Alton A K, Fechtel K, Kopczynski C C, Shepard S B, Kooh P J, Muskavitch M A
Department of Biology, Indiana University, Bloomington 47405.
Dev Genet. 1989;10(3):261-72. doi: 10.1002/dvg.1020100315.
Delta (Dl) is one of the six known zygotic neurogenic genes, each of which is essential for proper segregation of the embryonic ectoderm into neural and epidermal lineages. Molecular analysis of Dl reveals that it is a transcriptionally complex locus that yields multiple maternal and zygotic transcripts. DNA sequence analysis suggests that the predominant product of the locus is a putative transmembrane protein exhibiting homology to blood coagulation factors and epidermal growth factor of vertebrates. The structure of this product is consistent with the hypothesis that Dl participates in cell-cell interactions that are central to establishment of the epidermal lineage within the developing ectoderm. Genetic analyses demonstrate that Dl mutations can modify the imaginal phenotypes that result from heterozygosity for Notch (N) mutations as well as the interaction between particular alleles of Notch (N) and Enhancer of split [E(spl)], two other members of the neurogenic gene set. Vital interactions also occur between Dl and N. Given the structures of products encoded by N, Dl, and E(spl), we suggest that the synergistic phenotypic interactions observed among mutations in these three loci result from physical, as opposed to regulatory, interactions.
Delta（Dl）是已知的六个合子神经源性基因之一，每个基因对于胚胎外胚层正确分离为神经和表皮谱系至关重要。对Dl的分子分析表明，它是一个转录复杂的基因座，可产生多种母体和合子转录本。DNA序列分析表明，该基因座的主要产物是一种推定的跨膜蛋白，与脊椎动物的凝血因子和表皮生长因子具有同源性。该产物的结构与以下假设一致：Dl参与细胞间相互作用，而这种相互作用对于发育中的外胚层内表皮谱系的建立至关重要。遗传分析表明，Dl突变可以改变因Notch（N）突变杂合性导致的成虫表型，以及Notch（N）的特定等位基因与神经源性基因集的其他两个成员——分裂增强子[E(spl)]之间的相互作用。Dl和N之间也存在重要的相互作用。鉴于N、Dl和E(spl)编码产物的结构，我们认为在这三个基因座的突变之间观察到的协同表型相互作用是由物理相互作用而非调节相互作用导致的。
