Whiteley M, Noguchi P D, Sensabaugh S M, Odenwald W F, Kassis J A
Laboratory of Cellular and Molecular Biology, Food and Drug Administration, Bethesda, MD 20892.
Mech Dev. 1992 Feb;36(3):117-27. doi: 10.1016/0925-4773(92)90063-p.
Two independent P-element enhancer detection lines were obtained that express lacZ in a pattern of longitudinal stripes early in germband elongation. In this paper, molecular and genetic characterization of a gene located near these transposons is presented. Sequence analysis of a cDNA clone from the region reveals that this gene has a high degree of similarity with the Drosophila snail gene (Boulay et al., 1987). The sequence similarity extends over 400 nucleotides, and includes a region encoding five tandem zinc finger motifs (72% nucleotide identity; 76% amino acid identity). This region is also conserved in the snail homologue from Xenopus laevis (76% nucleotide identity; 83% amino acid identity) (Sargent and Bennett, 1990). We have named the Drosophila snail-related gene escargot (esg), and the region of sequence conservation common to all three genes the 'snailbox'. A number of Drosophila genomic DNA fragments cross-hybridize to a probe from the snailbox region suggesting that snail and escargot are members of a multigene family. The expression pattern of escargot is dynamic and complex. Early in germband elongation, escargot RNA is expressed in a pattern of longitudinal stripes identical to the one observed in the two enhancer detection lines. Later in development, escargot is expressed in cells that will form the larval imaginal tissues, escargot is allelic with l(2)35Ce, an essential gene located near snail in the genome.
获得了两条独立的P因子增强子检测系，它们在胚带伸长早期以纵向条纹模式表达lacZ。本文介绍了位于这些转座子附近的一个基因的分子和遗传学特征。对该区域一个cDNA克隆的序列分析表明，这个基因与果蝇的蜗牛基因有高度相似性（Boulay等人，1987年）。序列相似性延伸超过400个核苷酸，包括一个编码五个串联锌指基序的区域（核苷酸同一性为72%；氨基酸同一性为76%）。这个区域在非洲爪蟾的蜗牛同源物中也保守（核苷酸同一性为76%；氨基酸同一性为83%）（Sargent和Bennett，1990年）。我们将果蝇的蜗牛相关基因命名为蜗牛蛋白（esg），并将所有三个基因共有的序列保守区域称为“蜗牛盒”。一些果蝇基因组DNA片段与来自蜗牛盒区域的探针交叉杂交，表明蜗牛和蜗牛蛋白是一个多基因家族的成员。蜗牛蛋白的表达模式是动态且复杂的。在胚带伸长早期，蜗牛蛋白RNA以与在两条增强子检测系中观察到的相同的纵向条纹模式表达。在发育后期，蜗牛蛋白在将形成幼虫成虫组织的细胞中表达，蜗牛蛋白与l(2)35Ce等位，l(2)35Ce是基因组中位于蜗牛附近的一个必需基因。
