Andrew D J
Department of Cell Biology and Anatomy, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2196, USA.
Ann N Y Acad Sci. 1998 Apr 15;842:55-69. doi: 10.1111/j.1749-6632.1998.tb09632.x.
The homeotic gene, Sex combs reduced (Scr), is a master regulator of Drosophila salivary gland formation. Embryos in which Scr function is missing do not form salivary glands, and embryos in which SCR protein is expressed everywhere form extra salivary glands. However, other known proteins, including the homeotic protein Abdominal-B, the unusual zinc finger protein Teashirt, and the secreted signaling molecule Decapentaplegic (a TGF-beta family member), limit the recruitment of SCR-expressing cells to salivary glands. To learn the molecular details of how salivary gland gene expression is controlled and as a first step toward understanding how the SCR transcription factor controls salivary gland morphogenesis, we screened for genes expressed in the developing salivary gland. Among our best candidates for potential direct downstream targets of SCR in the salivary gland are the genes trachealess (trh), dCREB-A, jalapeño, and Semaphorin II (SemaII). Our genetic studies suggest distinct and important roles for each of these genes in salivary gland morphogenesis. Current work includes studying the molecular interactions between SCR and these downstream target genes and asking how target genes coordinate their activities to effect the cell biological changes required to build functional salivary glands.
同源异型基因“性梳减少”（Scr）是果蝇唾液腺形成的主要调节因子。Scr功能缺失的胚胎不会形成唾液腺，而SCR蛋白在各处都表达的胚胎则会形成额外的唾液腺。然而，其他已知蛋白质，包括同源异型蛋白腹部B（Abdominal - B）、异常锌指蛋白T恤衫（Teashirt）以及分泌性信号分子“五体不全”（Decapentaplegic，一种转化生长因子β家族成员），会限制表达SCR的细胞向唾液腺的募集。为了了解唾液腺基因表达是如何受到控制的分子细节，并作为理解SCR转录因子如何控制唾液腺形态发生的第一步，我们筛选了在发育中的唾液腺中表达的基因。在唾液腺中作为SCR潜在直接下游靶点的最佳候选基因中，有“无气管”（trachealess，trh）、dCREB - A、“墨西哥胡椒”（jalapeño）和信号素II（Semaphorin II，SemaII）基因。我们的遗传学研究表明这些基因中的每一个在唾液腺形态发生中都具有独特且重要的作用。目前的工作包括研究SCR与这些下游靶基因之间的分子相互作用，以及探究靶基因如何协调它们的活性以实现构建功能性唾液腺所需的细胞生物学变化。
