The distribution of Ultrabithorax transcripts in Drosophila embryos.

摘要: Abstract We have used in situ hybridization to monitor the distribution of Ultrabithorax (Ubx) transcripts during early stages Drosophila embryogenesis. When first detectable, late syncytial blastoderm, Ubx are broadly distributed from 20 50% egg length (measured posterior pole). By completion cellular blastoderm formation, a precisely bounded zone one segment wide is defined by accumulation high levels transcripts. This probably primordium for parasegment 6, that is, compartment third thoracic (T3) and anterior abdominal (A1). Following gastrulation, seven metameric units germ band express most or all cells both ectoderm mesoderm. principal domain expression sharply at superficial grooves embryo which mark A/P boundaries T3 A7, so consists parasegments 6-12. Outside this region, can be detected only few 5 13, amnioserosa. suggests major role lies morphological generally ascribed control bithoraxoid gene. Later embryogenesis, pattern transcript different each layers, suggesting controls regulate each. In ectoderm, but not mesoderm, accumulate differentially compartments. Probes prepared regions transcription unit show related patterns hybridization. These suggest 3.2-kb throughout wider expression, 4.7-kb accumulates preferentially 6.