Stage virtuel à Aarvård
Université Rennes 1 — UE Communication scientifique Stage virtuel à Aarvård Résumé — ce document contient la plupart des éléments nécessaires pour rédiger votre rapport de stage virtuel à Aarvård (la seule exception concerne les tableaux de données qui vous seront fournis séparément sous forme de fichier Excel et avec leur analyse statistique). Il se compose de deux parties. La première partie n'est pas sérieuse et figure juste ici pour planter le décor et vous distraire un peu. Vous pouvez donc la zapper totalement si vous le souhaitez sans aucun dommage à redouter concernant votre future note. La seconde partie est au contraire très sérieuse et contient les éléments que vous devrez impérativement utiliser pour la rédaction de votre rapport. Bonne lecture ! Pour toute question sur l'UE elle même : [email protected] Pour toute question que vous poseriez à un maître de stage : [email protected] (écrivez-lui en anglais, ça fait partie du jeu). Sommaire Première partie L'offre de stage qui vous enverra à l'université d'Aarvård Miko Nunaatuk vous souhaite la bienvenue au Santaklaus Institute Quelques vues photographiques de votre université d'accueil Lexique Thulaavik, ça peut toujours servir La passionnante histoire de l'université d'Aarvård La non moins passionnante biographie de son fondateur Quelques vues de Aarvård au temps des pionniers Interview de Miko Nunaatuk La page web personnelle de Miko 3 4 6 7 9 12 15 16 17 Deuxième partie La seule source (fictive) de biblio sur votre espèce d'étude Informations utiles sur l'équipement de votre labo d'accueil Description de vos manips, vital pour la rédaction de votre M&M 20 25 27 The very mysterious case of the Ouessant fly UE Bio 818 Communication Scientifique D. Poinsot The very mysterious case of the Ouessant fly 2 Santaklaus Wildlife Institute, Aarvård University, Greenland Lab internship position available for three month (Starting: January 15th, 2014) Behavioural mating isolation and larval competition between two Drosophila species Context: Drosophilids are the well known fruit flies developing from decaying vegetal material, the most famous being the laboratory model Drosophila melanogaster, which is found worldwide. We have discovered a new drosophilid species (D. enezeusae) which is wingless and strictly endemic to Ouessant (Enez Eusa, in Briton), a small windy island near the French Atlantic coast. Very surprisingly, D. melanogaster itself seems almost absent from this island. Project outline: The quasi absence of the cosmopolitan D. melanogaster from Ouessant as well as its obvious morphologic proximity with D. enezeusae are very puzzling. Your project will investigate whether the two species are isolated from a behavioural point of view, and you will determine to what extent their larvae show negative interactions when in competition for food. In practice, (i) you will observe the behaviour of males toward the odour of females from their own or the other species using a Y-shaped olfactometer, (ii) you will observe courtship and mating behaviours during intra and interspecific encounters, (iii) finally, you will check whether larvo-nymphal survival rate and adult fresh weight are affected when larvae of both species grow in monospecific or heterospecific groups, in conditions when food is limiting or not. Job profile: the successful applicant will have a BSc in biology and a keen interest for behaviour and evolution. Previous experience with insect rearing and some patience (repetitive observations must be made) are desirable. The ability to quickly distinguish a polar bear from a heap of snow might also be useful when walking on the campus. Contact Dr. Miko Nunaatuk Santaklaus Wildlife Institute, Aarvård University, 10 Harfang Lane, Aarvård, Greenland [email protected] D. Poinsot The very mysterious case of the Ouessant fly 3 Dr. Miko Nunaatuk Santaklaus Wildlife Institute, Aarvård University, 10 Harfang Lane, Aarvård, Greenland 25 miles north of Umaatuktituk, January the 1st, 2014 Dear trainee, A happy new year to you! I am very glad that you accepted this internship position and on behalf of all the staff I wish you a very good stay at the Santaklaus Wildlife Institute (which you will very rapidly call ―Santa‖ as everyone else). Wuk Qaamanassut, our caretaker, has certainly shown you into your room by now, and he has explained to you that the solid steel bars sealed to your window frames are not here to prevent your escape but rather to forbid rogue bears smashing their way in without being invited to. He also told you that because of those beautiful but dangerous neighbours it is strictly forbidden to wander alone on the campus after dark. Wuk also gave you a blanket for your bed. You may need it; it can get a bit cool at night. I will have the pleasure of being your supervisor for the duration of your internship, during which you will study behavioural traits in adult and larvae D. enezeusae when confronted with the closely related species D. melanogaster as previously agreed. Unfortunately, you will have to accept a remote supervision, because I have just been drafted to take part in the big decennial bear census, which means that for the next three month I will be on the move counting polar bears during their yearly migration, which means that I will not have the opportunity to meet you face to face. Fortunately, I have access to my e-mails via satellite link, so we can communicate anyway. Because weather conditions are a bit rough here, the connection can be erratic, especially during aurora borealis flares, so do not despair if I do not reply your requests immediately. You may ask me any questions you would ask to your supervisor but I cannot correct the paper for your exam: I do not read French at all! Of course, do not hesitate to ask other Aarvård students for advice about everyday questions such as ―The ink of my fountain pen has frozen solid! Do you know where I could buy pencils like those you use?‖. I wish you a good stay up here and please... Aargåff! (:)) Cheers, Miko You can contact me anytime at [email protected] D. Poinsot The very mysterious case of the Ouessant fly 4 Part One Introducing Aarvard University Notice: this first part is not necessary at all to write your exam paper. It is just here to create the atmosphere of a "real" internship. We hope you will enjoy it all the same. D. Poinsot The very mysterious case of the Ouessant fly 5 Aarvård today Aarvård campus in summer and in winter This may be you in a short while… If you see this by the window, stay indoors! Two different ways to take a break after lab experiments in Aarvård University D. Poinsot The very mysterious case of the Ouessant fly 6 A primer of the Thulaavik language Everyone at Santa speaks fluent English and you should not have any communication problem here. However, native students and staff will insist on also using (and making jokes at your expense) in Thulaavik. Therefore, learning a few strategic words and expressions would certainly help you a lot in making friends with the locals and enjoying a playful atmosphere during your stay with us. Aar Bear Vømir Beer Dåk [1] Yes; [2] I completely agree [1] No; [2] Don‘t even think about it Ked Kawåntrøp! Nonsense! Børdeiluk! Good heavens! Rü Frozen cod with fried ice (traditional dish) Fåar A delicious milk and eggs cake Køuignamåanutuq A very caloric survival cake made of seal fat and sugar marinated in whale oil (some people add a pinch of flour, purists don‘t). Vapøwuq Ether Dodomoochvapøwuq Etheriser (used to anaesthetize flies) Kuk Snow Finnkuk Powdery snow Krakuk Old snow with a crusty surface Refinnkrakuk New powdery snow fallen on old crusty snow Mortkuk Water (literally ―snow that is not snow anymore‖) Tregrokuk A very large amount of snow indeed Hjaerkuk Pristine snow accumulated on the wind-shielded side of rocks and shining like diamonds under the winter moon. A classical theme of Thulaavik romantic poetry Splotchkuk Snow which has been both vomited and urinated on. This very special kind of snow is not uncommon near student‘s lodging halls on late Thursday evenings. Very rarely – if ever – mentioned in Thulaavik romantic poetry, splotchkuk is on the other hand omnipresent in raucous Inuit drinking songs. Aarkuk A sleeping bear which you had most unfortunately mistaken for a large heap of snow. Often used metaphorically to mean ―violent and unexpected death‖ in Thulaavik literature. A Short Thulaavik phrasebook Wandering on the campus Aargåff! Kedj boutik piftuq grek då ? D. Poinsot Beware of the bear! (this happens to be the shortest grammatically correct sentence in Thulaavik) Isn‘t it a bit of your frozen nose I see on the ground? (traditional joke used to tease newcomers to the arctic) The very mysterious case of the Ouessant fly 7 Going out to the pub Onvaø Rü? Ked, jeveij vømir Would you care for some frozen cod and fried ice? No thanks, I‘ll just have a beer A few hours later, still at the pub Yuk? Anpåas me aarpoum Oh yeah ? Well, only last year, I shot a bear which was aak trogrø ! at least that big! Kedis voåar Hjaerkuk How about going out to watch the pure white snow søluuntuk ? twinkling under the winter moon? (a subtle proposition to get to know each other better in private) Kevuut påas Hjaernotche Would you fancy spending the next four-month-night apoåal me Aarpø ? naked on a bearskin with me? (a more direct approach) In the lab Dodomoochvapøwuq me øglik ? drosophila vieij metuk påar ? Børdeiluk ! somaaksgreløtuk aaki vapowuq ked vapo ! Be kretinuk drosophila køelceltuq -15°C termøk ? Thulaavik proverbs Tregrøkuk met pifnoår Aar guesstuuk Aerst trøil, dert amsooq Grenekuk, Frenekuk D. Poinsot Has anyone seen my etherizer? Would you have some spare drosophila bottles for me? Good heavens! It‘s so darn cold in here that my ether can‘t evaporate! Who the hell modified the settings of the thermostatic drosophila rearing room to -15°C??? A large snow heap with a black nose is most probably a bear (a fine example of old Inuit wisdom) First the hole, then the line (ice fishing proverb) Snow in November, snow in December (one of the many, many proverbs about snow) The very mysterious case of the Ouessant fly 8 Aarvård History Pikomiko, the man who saw the bear How and when Aarvård was really founded is — and will remain — a mystery. However, Thulaavik shamans have been repeating for centuries the legend of its founder, and here it is: Once upon a time, there was a courageous Thulaavik chief and fine seal hunter called Pikomiko (―Miko the very little‖) because of his diminutive size. One day that he had ventured far away on the pack, Pikomiko was surprised by a deadly blizzard. To save his life, he hastened to dig a hole in the snow accumulated at the base of a snow hill protected from the wind by a large block of ice. Unfortunately, ―someone‖ else had had the same idea before, and Pikomiko fell right through the ceiling of the den where a fierce female bear was nursing her two pups. Realising that his last hour (or, to be more precise, his last tenth of a second) had come, the small hunter bravely drew out his trusted hunting knife and prepared for a desperate last fight during which he was guaranteed to be shred to pieces. However, the female bear had been so startled by Pikomiko‘s sudden irruption that she collapsed and died on the spot, victim of a heart attack (a sad but not uncommon consequence of eating too much polysaturated animal fat, please make a note of this, little children). Pikomiko and the Bear (traditional inuit carving on a giant squid bladder stone, Thule Museum of traditional Inuit Fine Arts) Convinced that the Great Bear (Inuit‘s supreme divinity) had miraculously saved him from a certain death, Pikomiko adopted the two bear pups as his own sons and swore that never again would his tribe hunt bears. To prove it, he moved the Thulaavik base camp close to the coast, right into the path of the polar bear migration route, to mark the fact that bears and Thulaavik people were now of the same blood. To inform his new blood brothers that they would forever be welcome, the camp was called Aarvård (―bear camp‖). Several centuries later, Aarvård inhabitants would much prefer that their city does not lie straight in the middle of a polar bear migration route, but on the other hand they have grown into a close knit and watchful community. D. Poinsot The very mysterious case of the Ouessant fly 9 Viking invasions Aarvård is reliably recorded in history for the first time in the 11th century, at the time when it was discovered by a Viking expedition. The genesis of this trip was initially an attempt at ransacking the newly discovered Vinland (North America). For that purpose, the three most terrible Viking warlords of the far North decided to unite forces. Since they were the most dreaded warriors of their time, History has duly noted their names for posterity: Haarken the Destructor, Harulf the Deathblower, and Harald the Birdwatcher. However, things did not turn out as they had been planned. The day of departure had been carefully chosen, as usual, to avoid offending the many and susceptible Gods, and also to allow everyone to attend the 56th final game of the Nordic herring barrel throwing competition that took place every three years in Guteberg. On D-day, the men were all on the departure pier, ready to go and ransack the new continent. Haarken and Harulf were there since dawn, but Harald the Birdwatcher was nowhere to be seen. He was still at home, and so busy explaining to his servants how to take care of his pet sparrows during his absence that it was mid afternoon when he finally turned up. Furious, Haarken and Harulf had already left the port and their sails were mere little dots on the horizon. Harald had to wait for the next high tide and finally embarked with his men twelve full hours after his two warlord colleagues. By an irony history is fond of, these few hours of delay would both save his life and change his destiny forever. Within view of the coast of Iceland, Haarken and Harulf were surprised by a terrible hurricane which sunk their boats. None survived. The departure of Harald the Birdwatcher's expedition according to the Aradraggha tapestry (notice that more than three boats are represented, for emphasis. Notice also the birds, a symbolic representation of Harald's nickname). National History Museum of Brooghaven, Denmark. Arriving at the same place he day after, little did Harald know that the boats he was looking for on the horizon were in fact several hundreds of fathoms below him, resting forever on the bottom of the ocean. The tail of the tempest that had sunk them blew him north for several hundreds of miles and he found himself lost in the middle of an iceberg field. The crew was awed by the size of these mountains of ice, and to make matters worse a dense icy fog fell on the expedition. For three more days, they were lost and half frozen, waiting for their certain death when one of the iceberg would sooner or later crack their hull open when, on the morning of the fourth day, they heard a voice calling. The sea was empty and Harald‘s men were already speaking about evil spirits, when they had the surprise to discover an old and smiling D. Poinsot The very mysterious case of the Ouessant fly 10 man in a tiny boat which was pointy at both ends. This was no bad evil but more simply old Tiuk Inuuqtitak fishing squid for dinner in Aarvård bay. Thus was Aarvård discovered by the western world. However, it was to remain unknown for several more centuries since Harald and his men never came back. Indeed, a few hours only after their arrival, the drakkar was already blocked by ice. Later this winter, the pressure of the pack was too much for its tar-jointed planks and the hull was crushed with a terrific cracking noise. Forced to adopt their new home for good, Harald and his men took wives in Aarvård. The slow blending of the inuit and Viking customs led to a new culture, which explains why the Thulaavik language stands unique among inuit idioms in that it is a mixture or true inuktituq and Old Norse, hence the presence of typical Viking letters such as å or ø. Wruk the dragon, a creature from the rich Thulaavik bestiary. According to the legend, it is inspired from the decoration of the sail aboard Harald‘s boat, the Black Wren. (carved walrus ivory, Aarvard History Museum) D. Poinsot The very mysterious case of the Ouessant fly 11 Santaklaus, the man behind the institute Jack 'Santaklaus' Williamson was conceived in 1816 in Portsmouth, England, but born in Churchill, Canada, as a result of being the illegitimate son of the – then adolescent – future English Earl of S*** and Emy 'Applebottom' Williamson, the daughter of a poor periwinkle harvester. Indeed, his young highness had become pretty intimate (to put it mildly) with Emy Williamson after a popular dance party celebrating the first anniversary of the battle of Waterloo. When the Earl's father was informed of Emy's pregnancy by his furious future would-be-father-in-law, he snapped into action and offered cash in exchange for his absolute silence. To be on the safe side, he also demanded and obtained that the 6-month-pregnant Emy be sent to Canada where she would receive a stipend to sustain her and the baby. Accordingly, "Jack no-father", as he was nicknamed by his schoolmates, grew up in the snowy streets of Churchill where his professors at the St Saskatch boarding school praised his superb drawing skills and keen sense of observation, as well as a gift for Latin, which at the time formed the pre-requisite to do anything serious in the Good Society. However, Jack's scholarly education came to an abrupt and tragic end when his mother died from pneumonia during the hard winter of 1829. At age 12, Jack was an orphan for good, in a society which was fortunately not as rigid as Victorian England, but yet very hard on poor people. Jack survived as a newspaper boy for a few years during which he read a great deal and acquired a remarkably broad culture for a person of his modest condition, but pay was miserable and at age 16 he boldly joined the powerful Hudson Bay Company to become a trapper. Despite of his enthusiasm and natural endurance, young Jack knew nothing about life in the open and had to learn his trade following older experts, doing the hardest part of the work for a small percentage of their gains. However, he learned the ropes very fast and his reputation as marksman started to grow. 'Tobacco Pete', pictured here in studio just after his retirement in 1836. He was one of Jack's hard-nosed professors of wildlife, and a living legend in his own days. How he was capable of approaching even the most vigilant creatures of the wild while exhaling such a pungent tobacco smell will forever remain a mystery. D. Poinsot The very mysterious case of the Ouessant fly 12 Jack "Santaklaus" Williamson in 1859. He was then renowned all over Canada as the best trapper alive. (Kodiakhrome process, Thule National Gallery) However, what put Jack Williamson fundamentally apart from his many trapping colleagues roaming the uncharted immensity of the northern territories in search for valuable furs was his genuine interest for the beauty and adaptations of the creatures he was running after. All along his career, he kept a diary of his observations which he illustrated with hundreds of precise silver point drawings as well as several watercolors for which he spend what was for him a fortune on expensive artist-quality paint and paper (although he obviously made his wolf and sable hair brushes himself). The originals of these documents are now the most precious pieces kept at the Aarvård natural history museum. Even more unique among northern trappers of the time, Jack's real writing skills and his knowledge of the publication process allowed him to have some of his notes on the behavior of the local fauna accepted in respected scientific gazettes such as the Bulletin of the Saskatchewan Society for the Advancement of Science. His well deserved reputation as a northern wildlife expert led Jack to be solicited regularly to guide scientific expeditions. In particular, he led in 1857 the exploration of Ellesmere island, where he made the first description of arctic wolves hunting techniques in their natural environment. During this expedition, he had the opportunity to meet Inuit people for the first time as the team spent the winter in Thule (north Greenland), where he learned a lot about native survival techniques in extreme conditions. The following year, Jack was then chosen to accompany one of the first trans Greenland expedition, at the end of which the isolated village of Aarvård had its first contact with the Western world. There, Jack literally fell in love with the place, and with a charming inuit girl called Nanooka Qmutluq. Unfortunately, the demands of the expedition meant that Jack had to leave, but he promised to come back as soon as possible. On the way Back to Churchill, following the eastern Greenland coast, Jack noticed that polar bears could be seen almost every day, and that they were all heading south. He then realized that the expedition was following a migration route, a migration which was known by inuits for ages but had never been actually mapped. It D. Poinsot The very mysterious case of the Ouessant fly 13 was decided to follow the bears, which led the expedition to the southernmost tip of Greenland. Jack then reasoned with common sense that these were not the polar bears seen every year in Churchill, meaning that polar bears might be separated in more than one population. Back home at last in 1860 after three years of hardship, Jack was probably the one and only trapper of that century to buy a copy of Darwin's On the origin of species and one of the very rare men of his time to appreciate with an expert eye the enormous amount of fieldwork and careful observations carried out by its author. He emitted, however, a thundering roar of laugher when discovering Darwin's hypothesis that the whale descended from the polar bear's "habit of swimming with his mouth open to capture insects at the surface of the water". Jack had skinned a sufficiently large number of polar bears and seen enough corpses of whales, including fossil bones, to realize that it was quite a remote possibility, to say the least. A direct man as always, he did not hesitate to write Darwin a long letter about it, to which he joined a number of his personal observations of polar bear stomach contents (remarkably devoid of insects), and some of his drawings of fossil whale skulls. Charles Darwin toward the end of his life. At the time, his scientific correspondence with Jack ‗Santaklaus‘ Wiliamson filled two volumes. Jack ‗Santaklaus‘ Williamson at the turn of the century. The 80 years old extrapper had become the respected founder of the first university ever above the polar circle. (Whale oil on canvas, Greenland National Gallery, Thule). An excellent field naturalist himself, Darwin was impressed by the knowledgeable trapper and a long correspondence between the two men ensued, which was going to lay the foundations of a project that Jack was nurturing in the secret of his heart but did not have the funds to start. Then, just at the right moment, Jack, literally, struck gold. He was trapping in Klondike when he discovered what was to become one of the most productive gold mine of the area for the years to come. After a hard fought legal battle against local barons, Jack managed to establish his claim to his discovery. Now an extremely rich man at only 50, the most famous Canadian trapper of his time did not retire in the sunny south Carolina but on the contrary headed straight up north and boldly started a completely new career. Indeed, Jack loaded as much top-level scientific equipment as was possible in an old whale boat (the Stern) and set sail to Aarvård, where he arrived after a heroic navigation among icebergs in august 1866. Then, he did what nobody else but him would have dared to do : laying the foundations of a polar wildlife research institute in the middle of nowhere. D. Poinsot The very mysterious case of the Ouessant fly 14 Aarvård at the turn of the century A group of picturesque natives discussing about next seal hunting season? Well, think again. These are some of the participants of the international 1902 polar ecology conference. On the left (with snow googles) Eltiak Knusquunak, then director of the Santaklaus Wildlife institute and first dean of Aarvård University. He will be remembered as the best specialist of polar bear behaviour of the 20th century. Nanook Qmatuklivik, then a post-doctorate fellow at the Santa', pictured here on a field trip to collect krill samples somewhere in Aarvård bay in the early 1920's. He became the youngest Aarvård professor ever, at age 29, and was a recognized pioneer in polar marine food-chains. D. Poinsot The very mysterious case of the Ouessant fly 15 Aarvård Weekly Founded in 1875 A new fruit fly species discovered in France by an Aarvård scientist An interview with Miko Nunaatuk LGL — Dr Nunaatuk, what exactly have you discovered in Ouessant this summer? MN — A new Drosophila species, which has been named Drosophila enezeusae. Drosophilas are the very small flies that you see hovering over ripe fruits in summer and autumn in temperate and tropical regions, even in supermarkets. They are especially fond of melon and grapes. LGL — are they dangerous? MN — Not at all. Unlike so called ―domestic‖ or ―dung‖ flies, fruit flies are only interested in fermenting fruits. They would never land on dung or rotten meat (or a wound!), so they are not carriers of dangerous microbes. In fact, like some people, they are mostly attracted by the smell of... alcohol [laughs] LGL — Are these the small flies flying around sangria bowls at barbecue parties? MN — Exactly. In the wild, Drosophilas lay their eggs in over-ripe fruits because their larvae eat the flesh of fermenting fruits. As a result, drosophila larvae are extremely resistant to alcohol, and adults use its smell to find suitable sites to lay their eggs. They do not need a full sangria bowl though: Drosophilas are so minute that they can develop in the few drops left at the bottom of an empty wine or beer bottle. LGL — A sort of wine fly, then? MN — Indeed. In French the fruit fly Drosophila melanogaster is precisely called ―mouche du vinaigre‖ (i.e. ―vinegar fly‖), which proves that the proverb saying that flies cannot be caught using vinegar is... completely false! [laughs]. LGL — What makes Drosophila so interesting to science? MN — Their small size means that Drosophilas develop very fast. You can have a generation in less than ten days at 25°C. As a result, a lot of important genetic discoveries (e.g. mutations) have been made using these flies. What is less known is that the first animal launched in outer space in a rocket was not Laika the famous Russian female dog but... some American Drosophila melanogaster! This fruit fly is the first animal which genome has been entirely known. However, I am mostly interested in Drosophila ecology and behaviour, i.e. the way different drosophila species interact with their environment. LGL — What on earth gave you the idea to come and look for a new species in Ouessant? MN — Good question! [laughs] In fact, as with many scientific discoveries, this one was largely due to chance. I was in Europe for my holidays when I stumbled across my old friend Trevor McIntosh buying fresh lobsters in Lampaul‘s port! Put two scientists together, and within five minutes they are talking about science, of course. Since we are both interested in drosophila ecology (I met Trevor in Scotland during my thesis on drosophila), we decided to set a few traps to see which species were present on your island, just out of curiosity. And bingo! We hit on this new species! We were so excited that I spent the rest of my vacation collecting flies in Brittany to try finding other individuals. My wife nearly killed me for that. How I avoided getting a divorce this summer is anyone‘s guess [laughs] LGL — You say you used traps? What kind of traps do you use to capture fruit flies? MN — All you need to ―capture‖ drosophilas is any kind of small containers where you put ripe fruits. Hang those in the shade for a few days and if there are fruit flies around, believe me, they will find D. Poinsot The very mysterious case of the Ouessant fly 16 them and lay dozens of eggs! Sure enough, we captured fruit flies on your island, and they all belonged to this new species, which is extremely strange! LGL — What is so strange? MN — We would have expected to capture more than one species. More precisely, we were expecting to find many individuals of the very common species Drosophila melanogaster. On the contrary, in three weeks of research all over Ouessant we could only find a few of them on fruits sold in a grocery store. All individuals captured in the open were Drosphila enezeusae, while we could not find a single D. enezeusae on continental Britanny nor on nearby islands like Hoedic or Belle-Île, and this is another mystery. LGL — What about it ? MN — Drosophila enezeusae appears to exists in Ouessant and nowhere else! (in technical terms we would call it an endemic species). LGL — Does it mean it is in danger of extinction? MN — Absolutely not. The population here in Ouessant is extremely strong. You can put a trap anywhere on the island and catch dozens of them in no time. LGL — What is the next step in your research on this new species? MN — Trevor, who works in Europe all year, will continue field sampling and study the species in the field, so that we learn more about its ecology and life cycle in realistic climatic conditions. I will concentrate on laboratory work. There are a lot of preliminary experiments to do, and several Master students will come in my lab in Aarvård, Greenland, to participate in this exciting task this year, including, by the way, a French student of the University of Rennes. LGL — Isn‘t it a bit weird that an Inuit scientist studies the ecology of temperate or tropical species in a Greenland University? MN — Only if you believe in clichés about Inuit people. Science is not necessarily about what you see out of the window. Of course, at the Santaklaus Wildlife Institute I have colleagues who study the diving behaviour of seals or the effect of global warming on tundra lichen reproduction, but I can study drosophila behavioural ecology there as easily as in Paris or New York. Besides, our climate is a great advantage since I am authorised to import any species of Drosophila without any heavy quarantine regulations or sophisticated confinement equipment in our institute. LGL — Why is that? MN — If a fly manages to escape from our lab it will immediately freeze to death [laughs] Translated with permission from La Gazette de Lampaul (August 28th, 2013). Original interview by Nolwenn Kerdantec © 2013 La Gazette de Lampaul. D. Poinsot The very mysterious case of the Ouessant fly 17 http://perso.univ-aarvard.gro/miko.nunaatuk Miko Nunaatuk’s personal Web page Ain‘t I cute? These precious ivory snow googles were a gift from my beloved grandfather, Ptenko Nunaatuk, on my 16th birthday, the day I was authorised to lead my first walrus hunt. Current position: Senior Lecturer, Aarvård University (Biology Dpt., Santaklaus Wildlife Institute) Teaching responsibilities: Behavioural Ecology (unit Bio 715); Statistical analysis (stats701) Research interests: I am mostly interested in the way animal behaviour is shaped by ecological forces such as the interaction with natural enemies or the availability of food resource. My biological models are in the field of entomology, especially drosophilids (fruit flies) Short curriculum: 1987 BSc (Hons) in Biology, Aarvård University, Greenland. Final paper: ―Optimal scavenging behaviour of the arctic silver fox: how close can you get from a hungry polar bear?‖ 1989 MSc in Ecology, Winnipeg University, Canada. Final paper: ―Cold weather tactics of the arctic drosophilid Drosophila svalbardii: optimal foraging in extreme conditions‖ 1994 Ecological volunteer, Kerguelen Island. Participation to a scientific mission with the ―Terres Australes Françaises‖. Study of the feeding habits of an endemic predatory beetle. 1997 PhD. University of Inverness, Scotland. Fellow of the Loch Ness School of Biological Sciences. Thesis: ―Optimal foraging in drosophilids: how to apply Charnov‘s theorem when you have the brain of a gnat?‖ Recent publications: Nunaatuk M & McIntosh T, 2014. Drosophila enezeusae (sp. n.), a wingless drosophilid species from Ouessant. Proc. Plougastel-Daoulas Acad. Sci. 58:1027-1030. doi:12451.ppdas.547.245 Punaaqnassut K, Noonak J & Nunaatuk M, 2012. Frostbite avoidance in Drosophila saskatchewanae: when the going gets tough, the tough hides underground. Canadian J. Drosophila Ecol. Evol. 27:256-259. doi: 451.547.cjdee8545 Nunaatuk M., 2011. Drosophilid foraging behaviour: from equatorial rainforests to the toundra. Annu. Rev. Behav. Entomol. 17:374-392. doi:375.47.arbe245 D. Poinsot The very mysterious case of the Ouessant fly 18 Part Two And now some real work to do Important notice: this is the part you must read to write your exam paper. D. Poinsot The very mysterious case of the Ouessant fly 19 Proceedings of the Plougastel-Daoulas Academy of Sciences (2014) 58:1027-1031. doi:12451.547.245 SHORT NOTE Drosophila enezeusae (sp. n.), a wingless drosophilid species from Ouessant Miko Nunaatuk1 & Trevor McIntosh2 1 2 Santaklaus Wildlife Institute, 10 Harfang Lane, Aarvård, Greenland Loch Ness School of Biological Sciences, 105 Square Crescent Road, Inverness, Scotland Abstract — Here we report the discovery of Drosophila enezeusae (sp. n.), the first apterous drosophilid species ever described, which appears to be strictly endemic to Ouessant, a small and windy oceanic island a few miles off the westernmost tip of Brittany, France. Apart from its lack of wings and smaller size, D. enezeusae is morphologically almost undistinguishable from D. melanogaster in the female sex, although D. enezeusae males are easily recognisable by their distinctive genitalia. In Ouessant, D. enezeusae is the only drosophilid we could find. Quite incredibly, D. melanogaster itself seems totally absent from the island, except for very rare individuals found near containers of fruits recently imported from the continent. The reason why such a widespread species as D. melanogaster has not yet succeeded in colonizing an island receiving so much traffic from the mainland is deeply puzzling, and the evolutionary origin of D. enezeusae is not clear. INTRODUCTION Drosophilids (Diptera : Drosophilidae) are small fruit flies originating from the tropics, and counting among them the famous genetic’s lab workhorse Drosophila melanogaster, the first animal ever to have its genome fully sequenced. Yet, despite of a century of research and thousands of papers dealing with this animal model, surprisingly little is known about the basic ecology and behaviour of drosophilids in the field, although a large number of species have been described. The current count stands at over 3,000 (Russo et al., 1995), the most recently described species being D. Santomea, which is endemic to São Tomé island in the Gulf of Guinea and was discovered at the turn of this century (Lachaise et al., 2000). In this short note we describe the serendipitous discovery of yet another endemic species, Drosophila enezeusae (sp. n). Contrary to Drosophila santomea, which is more than 200 kilometres from the African coast, we found D. enezeusae nearly on the doorsteps of the many scientific labs housed in the university of Brest, more precisely on the small windswept French island of Ouessant, which has been inhabited for centuries and receives tourists by the thousands every summer. The present note deals with morphological characters only, the basic life history traits of the new species will be the subject of a future more ecology-oriented paper. D. Poinsot The very mysterious case of the Ouessant fly 20 MATERIAL AND METHODS The island of Ouessant Ouessant (48° 28' 00'' N 05° 04' 60'' W in Lampaul) is a small island (4 × 7km, 1158ha) situated 12 nautical miles (approx. 20km) from the westernmost tip of Britanny, France. It enjoys a mild oceanic climate (maximum daily august temperatures: 22°C, minimal February temperatures: 6°C) with a typical rainfall of 700mm (similar to Paris). On the other hand, Ouessant is very windy, being subject to 178 days of winds exceeding Beaufort 4, including serious gale force winds in autumn and winter. As a result, the vegetation is low (trees are almost absent) and constituted essentially of a low turf near the coast and moors further inland. The island is criss-crossed by a network of low stone walls, which are not maintained as they used to be and are often hidden by brambles overgrowth (Rubus sp.). Mammals are rare on the island, but the avian fauna is quite rich both in marine and migratory species, such as the Northern Fulmar (Fulmarus glacialis), Great Shearwater (Puffin gravis), European Storm Petrel (Hydrobates pelagicus) and raptors such as the Osprey (Pandion halietus) or the emblematic Peregrine falcon (Falco peregrinus), which is observed nearly all year long (Audevard, 2006). Finally, Ouessant is home of 960 Ouessantins in winter, and receives several thousands of visitors during the summer season. As far as the historical record shows, it has been inhabited continuously in historical times, and archaeological evidence suggests a human presence as early as 1500yrs BC. Sampling sites Ouessant being a very small island, the 13 different locations sampled cover most of the area and are representative of the vegetation cover found. Their characteristics are described in table 1. As a second step, nearby continental locations (Brest, PlougastelDaoulas, the Crozon Peninsula) were included in the sampling scheme, as well as the neighbouring islands of Molène, Hoëdic or Sein. However, not a single Drosophila enezeusae was captured from this second series of traps (which yielded a total of 3,428 flies of the genus Drosophila). Accordingly, this paper will only deal with the Ouessant results. Sampling method All sampling in Ouessant was carried out on 5-10 August, 2013. Plastic bottles (250ml) were fitted with a U shaped aperture on the side and baited with ripe banana and baker’s yeast. The bottles where left in place for seven consecutive days, shaded from direct sun to avoid overheating (whenever possible, they were left dangling under brambles bushes (Rubus rubus). Upon collection, each trap was immediately sealed with cellotape and adult flies seen in the bottle were captured with an insect aspirator for examination under the binocular after light diethyl-ether anaesthesia. The larvae were left to develop in the shade at ambient temperature (day:2025°C, night:16-18°C) and were identified upon emergence of adults. D. Poinsot The very mysterious case of the Ouessant fly 21 Identification All drosophilids captured in Ouessant were all compared with the reference Drosophila collection of the first author under a dissecting microscope (max. magnification of 40x). RESULTS A total of 601 drosophilids were collected. With the exception of the trap placed in the fruits section of Lampaul’s grocery store (where two Drosophila melanogaster individuals were recovered out of 40 captures, table 1), all individuals belonged to an apterous and yet unknown species of the genus Drosophila, which we chose to name Drosophila enezeusae for its supposed endemic nature (the Breton name of Ouessant is Enez Eusa). Table 1. Sampling sites and identification of Drosophila sp. captured in Ouessant (5-10 August 2013). Each site was fitted with a trap baited with ripe banana and baker's yeast (see text for details) Location Characteristics Individuals recovered D. enezeusae D. melanogaster Lampaul 1 Private garden 22 – Lampaul 2 Grocery store* 38 2 Mez Notariou Bramble patch 147 – Locqueltas Sheep pasture 50 – Nividic Point Low coastal turf 3 – Niou Uhella Old pasture 15 – Kergadou Bramble patch 153 – Calgrac'h Cove Low coastal turf – – Stiff Point Low coastal turf – – Penn Ar Lan Wetland 17 – Stang Merdy Wetland 8 – Lann ar Grac'h Moorland 12 – Penn ar Roc'h Cove Low coastal turf 4 – Feunteun Velen Bramble patch 135 – * trap left for one night only, at owner's request 599 2 Diagnosis Apart from its lack of wings, D. enezeusae is extremely similar morphologically to D. melanogaster in females (figure 1). On the other hand, D. enezeusae males are readily distinguishable from D. melanogaster males by their very conspicuous black genital plate. A comparison of the aedeagus confirms a marked morphological difference (fig 1 d,e). These data strongly suggest that D. enezeusae is a new species, although it is obviously very closely related to D. melanogaster. Another distinguishing character between the two species is the smaller size in D. enezeusae (it is approximately 20% smaller than D. melanogaster in both sexes). This reduced size is not due to poor food sources since it is maintained after several generations in the lab in un-crowded conditions on high quality medium (data not shown). D. Poinsot The very mysterious case of the Ouessant fly 22 b a c d e Figure 1. Male (a, b) and female (c) of D. enezeusae. Notice the lack of wings and the conspicuously large genital plate in the male (arrow). Pannels (d) and (e) show a comparison between the male genitalia of D. melanogaster and D. enezeusae, (respectively). Notice in D. enezeusae the very large genital plate, the broader aedeagus as well as its peculiar trident shape. Bar: 100 m. Voucher specimens of the new species have been donated to the University of Brest. Holotypes are kept both at the British Museum (accession number BMS.251.278.1.695) and the Aarvård University Natural History Museum (accession number AAR.26.586.984) DISCUSSION [not reproduced here so as not to stiffen your creativity when trying to interpret your own results about the interaction between Wolbachia and the very mysterious Ouessant fly] D. Poinsot The very mysterious case of the Ouessant fly 23 CONCLUSION AND PERSPECTIVES The discovery of a new Drosophila species brings more questions than it answers, the first being of course: is it a bona fide species or merely a subspecies of D. melanogaster? To answer it, crossing experiments with D. melanogaster will be carried out shortly. Moreover, we will determine whether the reproductive isolation between these two drosophilids is due to pre-mating (i.e. behavioural) or post-mating (genetic) factors. If D. enezeusae is, as we believe, a true species, the question of how its speciation event took place and the extremely puzzling absence of D. melanogaster on Ouessant must be investigated. Acknowledgments The first author wishes to thank his friend B. Le Garff, whose extensive knowledge of Ouessant was a great help in discovering what D. enezeusae — if only it existed for real — might develop on: blackberries. My own initial ―guesstimate‖ (fallen cider apples) was ridiculous since there are virtually no trees in Ouessant! The skillful hands of T. Frétey and B. Le Garff were also helpful in strategically altering the genitalia of a genuine South American drosophila species to create those of D. enezeusae. The (beautiful) original ink drawings of genitalia are due to Marta Erps Breuer (1902-1977), designer and lab technician at the Universidade de São Paulo, and a former Bauhaus student. REFERENCES Audevard A., 2006. L'année ornithologique. Bulletin Ornithologique Île Ouessant 15:1– 56. [http://audevard.aurelien.free/IMG/pdf/Bulletin-ornitho_Ouessant_2006.pdf] Lachaise D., Harry M., Solignac M., Lemeunier F., Bénassi V & M.L. Cariou, 2000. Evolutionary novelties in islands: Drosophila santomea, a new melanogaster sister species from São Tomé. Proceedings of the Royal Society of London B. 267:1487–1495. doi:10.1098/rspb.2000.1169 Russo, C.A.M., Takezaki N. & M. Nei, 1995. Molecular phylogeny and divergence times of Drosophilid species. Molecular Biology and Evolution 12:391–404. D. Poinsot The very mysterious case of the Ouessant fly 24 Useful information to get a feel of your virtual experiments. Basic drosophila lab equipment Drosophila bottles Such bottles are typically 250 ml flasks with a wide aperture for easier manipulation. They are filled with a one-inch layer of drosophila medium (25ml). The traditional (and most practical) way to close drosophila bottles is by means of a large cotton wool plug, which can be removed using the little finger alone if necessary, the rest of the hand being free to manipulate various objects. For better hand comfort, crude (non hydrophobic) cotton wool is used. Drosophila tubes These vials are typically not more than 15cm high (i.e., short enough to be put upright under a binocular) with a 2,5cm or wider diameter (i.e. a wide aperture). They have a flat bottom so that they can safely stand upright on their own, although they are moved around in bunches of 20 using plastic vial holders. Each tube holds a one inch layer of drosophila medium (5ml). Again, the most practical way to close them is by means of a small crude cotton ball. Drosophila medium The medium is the solid food seen at the bottom of bottles and tubes found in all drosophila labs. Since the days of Thomas Hunt Morgan (who used... ripe bananas) several dozens of media have been invented, but the basic components are usually wheat or maize flour and baker's yeast, cooked together with agar to form a solid layer firmly attached to the bottle, which can be put upside down and bumped on a rubber mat repeatedly without any medium falling. Some media use live bakers' yeast, others are axenic (sterile, at least at the moment when they are put into the bottle). David's medium (see further below) is an axenic medium. Rubber mats Also known as « bottom bumpers », they are small rugs (15x15cm) made from any soft and bumpy surface (often odd bits of used carpets) which are put on drosophila lab benches so that the bottom of drosophila bottles or tubes can be briskly bumped on the bench without breaking. This fast bumping action is one of the most frequent movement seen in drosophila labs around the world. Its role is to make all flies fall temporarily at the bottom of the bottle so that the plug can be open without any drosophila escaping. This gesture is used in particular when flies need to be masstransferred from an old bottle into a new one to maintain stocks. Insect "pooters" They are small « fly aspirators » made of one straight glass tube with an internal diameter of a few millimetres (enough for a drosophila to be sucked D. Poinsot The very mysterious case of the Ouessant fly 25 in) fitted tightly by a long plastic tube which the manipulator holds in his/her mouth. This aspirator is used to suck a fly in or flush it out, allowing it to be transferred from one tube to the other without the need to open the cotton plug (the glass tube is small enough to be inserted while the plug is in place). Needless to say, the junction between the two tubes is fitted with a fine fly-proof screen; otherwise drosophila workers would eat a large number of flies every day. Etherizers They are the traditional devices used to anaesthetize (or kill) drosophila. They are made of a chamber where ether diffuses and into which flies fall through a funnel. The difference between ether fly anaesthesia and ether fly murder being only a subtle question of timing, which strongly depends on the amount of ether put into the apparatus, the temperature of the room and the experience of the scientist, beginners are guaranteed to involuntarily slaughter quite a number of innocent flies before they get used to their etherizer. In modern labs, etherizers tend to be replaced by CO2 flow beds, but these have a rough surface and when it comes to sort rapidly large numbers of flies, they are not as efficient as the traditional ceramic white tile on which you dump your anaesthetised (or dead) flies. Fly strains in our laboratory D. enezeusae (wild type) Our D. enezeusae lab strain was established in August 2013 from more than a hundred females recovered captured from traps baited with ripe banana and yeast put in various places on the island of Ouessant during my summer vacation in France (for a full list of locations see table 1 in Nunaatuk & Mc Intosh, 2014). Since that time, the strain (known in our lab as « Ouessant 2013 ») is mass-bred here in the entomology lab of the Santaklaus Wildlife Institute. The strain is maintained on David's axenic medium (David J., 1962. A new medium for rearing Drosophila in axenic conditions. Drosophila Information Service 93:28.). We maintain at least 400 reproductive couples per generation to minimize drift and inbreeding. D. melanogaster (wild type) Our D. melanogaster lab strain was also established in August 2013 from more than a hundred females captured from traps baited with over-ripe carrots put on the balcony of the Paimpont research station, near Rennes. Since that time, the strain (known in our lab as « Paimpont 2013 ») is massbred as described above. Summary: Table 1. Strains to be used during the project Identification D. Poinsot Species Full strain name enez D. enezeusae Ouessant 13 mel D. melanogaster Paimpont 13 The very mysterious case of the Ouessant fly 26 Experiment 1 : Attraction of males toward the odour of conspecific and heterospecific virgin females In all experiments using adults, only use individuals which have been selected as virgin from the pupal stage and have been put in isolation, one per 25 ml vial. Pupae are translucid so you can recognize males from female before they emerge by looking for the sexual combs that males harbor on their legs. In this first experiment, you will test whether D. melanogaster and D. enezeusae virgin males are attracted to pheromones released by virgin females from the other species. To do so, you will use a two-arms ("Yshaped") olfactometer (see below the quick sketch I made). The male will be placed at the base of the Y-shaped tube and will receive two different airflows from each branch of the olfactometer. This airflow will be air only (control) or air which has passed through a chamber containing a virgin female (female odour). You will then record the time spent by the male in each of two meaningful zones : (i) arm A of the olfactometer, (ii) arm B of the olfactometer. Males will not see the females, and will not be able to reach them (the arms are obstructed by fine mesh gauze). You will confront D. melanogaster and D. enezeusae males with the three following dual choices: D. Poinsot The very mysterious case of the Ouessant fly 27 a) virgin D. melanogaster female vs air b) virgin D. enezeusae female vs air c) virgin D. melanogaster female vs virgin D. enezeusae female Here is how you will proceed : 1) check that the airflow of the olfactometer is OFF. 2) Using you fly aspirator, gently put a 3-day old virgin female in chamber A or B at random (do not use systematically the same chamber for a given treatment, to avoid position bias). 3) Leave the other chamber empty (case of a test "female vs air") or gently place a female of the other species in it (case of a test "melanogaster vs enezeusae"). 4) Open the valve and set the airflow to 5cm/s. The air reaching the base of the olfactometer will now come from both chambers. 5) Using your fly aspirator, gently place a 3-day old virgin male in the obscured part of the olfactometer (resting area). 8) start your chronometer. 9) When (and if) the male gets out of the obscured resting zone, record the time spent in each zone : arm A, arm B. 10) After three minutes, stop the recording, remove the male and the female from the olfactometer and prepare for a new repeat. You will need 20 repeats per treatment. 11) Between different treatments, dismantle the olfactometer, wash the Y tube and the chambers in soapy hot water and let dry overnight. 12) If the gaz bottle runs empty, call Wuk on extension 6711 and ask for a new one. (see next page for experiment 2) D. Poinsot The very mysterious case of the Ouessant fly 28 Experiment 2 : Compared behaviours during conspecific and heterospecific encounters between virgin males and virgin females In this experiment, you will test whether D. melanogaster and D. enezeusae accept to mate with individuals of the other species. To do so, you will compare the behaviour of homospecific and heterospecific couple of virgin flies by observing encounters during 30 minutes. You will record the number of typical courtship behaviour of males as well as the occurence and duration of mating if it takes place. Here is what you will do in practice : 1) 24h before the experiment, isolate virgin males and females in individual 25ml tubes. 2) With your fly aspirator, gently introduce a virgin female in an observation chamber (these chambers are made of plexiglas, 10mm in diameter and 3mm high with a transparent lid and a small hole at the bottom to introduce flies). 3) wait for one minute for the female to settle in its new environment. 4) With your fly aspirator, gently introduce a virgin male in the chamber, close the hole and immediately place the observation chamber under a dissecting microscope. 5) start your chronometer and note (i) the number of attempts of the male to court the female (the female walks rapidly towards the female, follows her and then orients 90 degrees from her body, trying to attract her attention by extending the wing -- if it has any), (ii) the occurence of mating (the male mounts the female) and, (iii) if a mating occurs, the total duration of the copulation (time from mounting to dismounting by the male). 6) change or wash in alcool the mating chamber between two couples. 7) repeat 20 times (i.e. observe 20 different couples for each kind of encounter). (see next page for experiment 3) D. Poinsot The very mysterious case of the Ouessant fly 29 Experiment 3 : Competition between D. melanogaster and D. enezeusae larvae In this experiment, you will test the effect of competition between D. melanogaster and D. enezeusae larvae in two situations : (i) food abundant and (ii) food scarce. To do so, you will place controlled numbers of first instar larvae of both species either on a sufficient or an insufficient amount of food. You will then count the number of adult individuals of each species to complete sucessfully their development, and weight them using an ultraprecise Sartorius scale. 1) 48h before the experiment, put at least100 couples of mated flies in a plexiglas cage with a small Petri dish containting David's medium (obviously, prepare one cage with D. melanogaster and another for D. enezeusae). Scratch the medium with a needle beforehand to create grooves (groves induce oviposition). 2) put the cage in the 25°C thermostated drosophila box so flies are warm and cozy. In the name of the Great Bear do *not* touch the thermostat of this box ever, ever, and I mean it. The last trainee who modified this sacred setting was sentenced to shovel the snow from the lab's door all the way to the Dean's office as a punition. 3) after 48h exactly, collect first instar larvae delicately with the tip of a humidified small brush to use them in your experiments. 4) for the "food abundant" condition, put either 20 larvae of one species or 10 larvae of both species in a 25ml vial containing 5ml of David's medium, this is more than enough for this number of larvae (5ml of David's medium is sufficient to obtain 100 larvae in good conditions). Close the tube with a cotton pad and place back at 25°C until emergence (approximately 9 days later). You will prepare 10 replicate tubes for each treatment (hence 200 larvae per treatment). 5) for the "food scarce" condition, do as above but with 100 larvae (or 50+50) in a vial containing only 1ml of Davids medium. This will create a severe competition for food, especially during the third instar. Again, prepare 10 replicate tubes per treatment (hence 1000 larvae per treatment). 6) during the emergence period, you will need to work round the clock (checking emergences every six hours) so bring a sleeping bag and an alarm clock to the office, and plenty of coffee (remember that it is forbidden to be out alone on the campus after dark, because of wandering bears). 7) check vials for emergences every 6h, kill emerging flies using the etherizer, sort them by species and weight them individually (to 0.01 mg accuracy) using our Sartorius microscale. Do not spill coffee on the microscale please, this stuff costs a fortune (the microscale, not the cofee). D. Poinsot The very mysterious case of the Ouessant fly 30 Before I forget: here is a quick sketch I made under the microscope: it compares the mouth hooks (the hard chitinized parts larvae use to feed) in the two species under study. The picture shows the hooks of the last larval stage (i.e. the L3). If it can be of any help for your project, be my guest. Results and statistical analysis Will be sent to you shortly (eh, you have to carry-out the experiments firsts!) but you can start straightaway to study the scientific literature on Wolbachia-host relationships (especially in drosophilids), you can start to write your Material & Methods, you can start to sketch ideas for your Introduction, you can start to think about the kind of figures and tables you will use, there is a lot of work to be done before you get the results! --- Good Work ! --- D. Poinsot The very mysterious case of the Ouessant fly 31
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