Kopczynski C C, Alton A K, Fechtel K, Kooh P J, Muskavitch M A
Department of Biology, Indiana University, Bloomington 47405.
Genes Dev. 1988 Dec;2(12B):1723-35. doi: 10.1101/gad.2.12b.1723.
Delta (D1) is required for normal segregation of the embryonic ectoderm into neural and epidermal cell lineages in Drosophila melanogaster. Loss-of-function mutations in D1 and other zygotic neurogenic loci lead to expansion of the neuroblast population at the expense of the dermoblast population within the ectoderm. Characterization of the transcriptional organization and maternal/embryonic expression within the chromosomal interval corresponding to D1 reveals that the locus encodes multiple transcripts: a minimum of two maternal transcripts, approximately 4.5 and 3.6 kb in length, and four zygotic transcripts, approximately 5.4 (two distinct species), 3.5, and 2.8 kb in length. These transcripts differ on the bases of differential splicing and differential polyadenylation site choice. The DNA sequence of a cDNA clone representing the predominant transcripts of the locus indicates that D1 encodes a transmembrane protein homologous to blood coagulation factors and epidermal growth factor. The relationship between coding sequences and transcript-specific exons within the locus suggests that D1 encodes multiple translational products.
在黑腹果蝇中，胚胎外胚层正常分离为神经和表皮细胞谱系需要Delta（D1）。D1和其他合子神经源基因座的功能丧失突变会导致神经母细胞群体扩张，以外胚层内的成皮细胞群体为代价。对与D1对应的染色体区间内的转录组织和母体/胚胎表达进行表征，发现该基因座编码多种转录本：至少两种母体转录本，长度约为4.5和3.6 kb，以及四种合子转录本，长度约为5.4（两种不同的物种）、3.5和2.8 kb。这些转录本在可变剪接和可变聚腺苷酸化位点选择的基础上有所不同。代表该基因座主要转录本的cDNA克隆的DNA序列表明，D1编码一种与凝血因子和表皮生长因子同源的跨膜蛋白。该基因座内编码序列与转录本特异性外显子之间的关系表明，D1编码多种翻译产物。
