Underwood E M, Lengyel J A
Department of Biology, University of California, Los Angeles.
Dev Genet. 1988;9(1):23-35. doi: 10.1002/dvg.1020090104.
The unique cellular and genetic events which occur during the first few hours of Drosophila embryogenesis suggest that there are genes whose function is entirely or largely limited to this stage; this is supported by both genetic and molecular evidence. To identify some of these genes and characterize the relative contribution of specifically maternal and specifically zygotic transcription to early embryogenesis, we used competition and differential screening of a Drosophila genomic DNA library to obtain blastoderm- and maternal-differential sequences [Roark et al.: Dev Biol 109:476-488, 1985]. We describe here the Eco RI restriction fragments, chromosomal location, and size and developmental pattern of expression of the RNAs transcribed from 19 maternal-differential sequences. Five sequences encode maternal-specific transcripts (50-150-fold more abundant in maternal RNA than at any other stage). The maternal-specific and maternal-differential sequences are located at single sites on all major chromosome arms. Comparison of these sites with the sites of presently mapped maternal-effect genes shows several possible correlations, including one region containing three maternal-effect lethal mutations and two maternal-specific sequences.
果蝇胚胎发育最初几个小时内发生的独特细胞和基因事件表明，存在一些基因，其功能完全或很大程度上局限于这一阶段；遗传和分子证据均支持这一点。为了鉴定其中一些基因，并表征特定母体转录和特定合子转录对早期胚胎发育的相对贡献，我们利用果蝇基因组DNA文库的竞争筛选和差异筛选来获得囊胚期差异序列和母体差异序列[罗克等人：《发育生物学》109:476 - 488，1985年]。我们在此描述了从19个母体差异序列转录而来的RNA的Eco RI限制性片段、染色体定位、大小及表达的发育模式。五个序列编码母体特异性转录本（在母体RNA中的丰度比其他任何阶段高50 - 150倍）。母体特异性序列和母体差异序列位于所有主要染色体臂的单个位点上。将这些位点与目前已定位的母体效应基因的位点进行比较，发现了几种可能的相关性，包括一个区域含有三个母体效应致死突变和两个母体特异性序列。
