Parameters of the wing imaginal disc development ofDrosophila melanogaster

摘要: Abstract Using X-ray-induced somatic crossing-over, a clonal analysis of the wing disc development ofDrosophila melanogaster was carried out. Individuals carrying y in X-chromosomes, andscJ4 (y+)jv andmwh either 3L chromosome were irradiated at different developmental stages and inducedy;mwh andjv twin clones studied with respect to their frequencies, sizes, shapes. The results indicate that imaginal cells grow exponentially from beginning larval period up puparium formation. A total 15.6 divisions is necessary complete adult number cells. division rate constant intermolt periods, but apparently decreases during molt periods. average cell cycle time for about 8 hours 30 minutes. sensitivity SCO more or less periods (0.2–0.4%). It increases pupal 4 times presumptive hair 5–10 trichogen orientation mitotic spindle appears be major morphogenetic process. Cell are preponderantly oriented along proximodistal axis alternating transverse longitudinal random notum region. Clones indeterminate patterns. At least two determinative events separate into prospective pathways. From period, dorsal ventral do not mix over margin. Forty before formation, induced able give rise several bristles both same clone. differential mitoses giving bristle organ appear equivalent to, take place as,