Figure 13.17: Developmental program of Drosophila melanogaster.
Figure 13.17: Developmental program of Drosophila melanogaster. Figure 13.19: Early development in Drosophila. Early mitotic divisions Figure 13.20: Fate map of the Drosophila blastoderm, which shows the adult structures that derive from various parts. Adapted from J. C. Hall, W. M. Gelbart, and D. R. Kankel (M. Ashburner and E. Novitski, eds.). The Genetics and Biology of Drosophila, vol. 1a. Academic Press (1976): 265-‐314. ring loss at mitosis Sex mosaics (gynandromorphs) resulting from ring loss Drosophila sexual dimorphism Courtship and mating Figure 13.21A: Segmental organization of the Drosophila embryo and larva. Courtesy of Thom Kaufman and F. Rudolf Turner, Indiana University at Bloomington. Figure 13.30: Relationship between larval and adult segmentation in Drosophila. Figure 13.18: Early development in Drosophila melanogaster from stage 1 immediately after fertilization through stage 12 about 9 hours after fertilization. Courtesy of Thom Kaufman and F. Rudolf Turner, Indiana University at Bloomington. Figure 13.21B: Segmental organization of the Drosophila embryo and larva. Figure 13.17: Developmental program of Drosophila melanogaster. Figure 13.31: Adult Drosophila structures Overview of segmentation bcd ß ! ! ! ! à nos hb – gt – Kr – kni – gt – (hb) ! ! ! ! ! h, eve ,ftz, opa, prd ! ! ! ! ! en, wg, hh, ptc ! ! ! nanos is dispensable in absence of maternal hunchback Maternal bcd controls A/P position Hb Kr Figure 13.25: An embryo of Drosophila, approximately 2.5 hours after fertilization Courtesy of James Langeland, Sean Carroll, and Stephen Paddock, University of Wisconsin at Madison. Overview of segmentation Figure 13.26: Characteristic seven stripes of expression of the gene hairy in a Drosophila embryo approximately 3 hours after fertilization. Courtesy of James Langeland, Sean Carroll, and Stephen Paddock, University of Wisconsin at Madison. Enhancers determine stripe expression Gap gene binding sites in eve stripe 2 enhancer negative ! ! ! positive Location of pair-‐rule stripes relative to gap genes Influence of gap genes on eve stripe 2 Expression of pair rule genes Figure 13.28: Expression of the segment-‐polarity gene engrailed partitions the early Drosophila embryo into 14 regions. Courtesy of James Langeland, Sean Carroll, and Stephen Paddock, University of Wisconsin at Madison. Segment polarity genes define compartment boundaries Wg En Overview of embryonic development Hox gene expression in embryos Segment identity is determined by Hox gene expression The Antennapedia mutation Segment identity is determined by Hox gene expression A closer look at BX-‐C Figure 13.34A: Wildtype Drosophila showing wings and halteres (the pair of knob-‐like structures protruding posterior to the wings). Courtesy of Edward B. Lewis. Used with permission of Hugh Lewis. Figure 13.34B: A fly with four wings produced by mutations in the bithorax complex. Courtesy of Edward B. Lewis. Used with permission of Hugh Lewis. Hox gene conservation
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