Jones N A, Kuo Y M, Sun Y H, Beckendorf S K
Division of Genetics, Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA.
Development. 1998 Nov;125(21):4163-74. doi: 10.1242/dev.125.21.4163.
What are the developmental mechanisms required for conversion of an undifferentiated, two-dimensional field of cells into a patterned, tubular organ? In this report, we describe the contribution of the Drosophila Pax gene eye gone to the development of the embryonic salivary glands and ducts. eye gone expression in salivary tissues is controlled by several known regulators of salivary fate. After the initial establishment of the salivary primordium by Sex combs reduced, fork head excludes eye gone expression from the pregland cells so that its salivary expression is restricted to the posterior preduct cells. trachealess, in contrast, activates eye gone expression in the posterior preduct cells. We have previously described the process by which fork head and the EGF receptor pathway define the border between the gland and duct primordia. Here we show that eye gone is required for the subdivision of the duct primordium itself into the posterior individual duct and the anterior common duct domains. In the absence of eye gone, individual ducts as well as the precursor of the adult salivary glands, the imaginal ring, are absent. We took advantage of this ductless phenotype to show that Drosophila larvae do not have an obligate requirement for salivary glands and ducts. In addition to its role in the salivary duct, eye gone is required in the embryo for the development of the eye-antennal imaginal disc and the chemosensory antennal organ.
将未分化的二维细胞区域转化为有图案的管状器官需要哪些发育机制？在本报告中，我们描述了果蝇Pax基因eyegone对胚胎唾液腺和导管发育的作用。唾液组织中eyegone的表达受几种已知的唾液命运调节因子控制。在由性梳减少基因初步建立唾液原基后，叉头蛋白将eyegone的表达排除在腺前体细胞之外，使其在唾液中的表达仅限于后导管前体细胞。相反，无气管基因激活后导管前体细胞中eyegone的表达。我们之前已经描述了叉头蛋白和表皮生长因子受体途径界定腺和导管原基之间边界的过程。在这里我们表明，eyegone是将导管原基本身细分为后单个导管和前共同导管区域所必需的。在没有eyegone的情况下，单个导管以及成年唾液腺的前体——成虫环均不存在。我们利用这种无导管表型表明果蝇幼虫对唾液腺和导管没有绝对需求。除了在唾液导管中的作用外，胚胎中eyegone对于眼触角成虫盘和化学感应触角器官的发育也是必需的。
