IMED2004 Study Guide - Final Guide: Gap Gene, Body Plan, Zygote
Document Summary
D v axes in drosophila & vertebrates are related, but inverted. Have signaling and tf that enforce ventral and dorsal fates. Conserved pathway for regulating nuclear transport of transcription factors in. Indication of how highly conserved signaling pathways are. Sequential expression of different sets of genes establishes body plan along anterior-posterior axis. Maternal effect localised mrna & proteins translated. After fertilisation give positional information to activate zygotic genes. Meg depositing mrna and getting differential expression and conc of proteins from those genes. All that determine no. of segments in fly. Then homeotic genes determine identity of what these cells will be. Mutations in these cause diff phenotypes of embryo. First zygotic a-p genes = gap genes. (mutants have gap in normal segmentation) promoters have differential sensitivity. To the maternally derived tf (bicoid, hb-m, caudal) One branch to establish correct number of segments one branch to assign proper identity to each segment. 1st zg to be activated by meg.
