Salivary Gland Genetic Markers

果蝇唾液腺的胚胎发育 提供了几个优势，分析基因参与， 决定和区别。在胚芽的外胚层 在带状延伸的胚胎中，腺体开始发育， 这表明涉及几个已知的模式， 调节基因然后，在几个 小时，这意味着从承诺到承诺几乎没有步骤 差异化。该提案提出了确定 在这个早期阶段在唾液腺中起作用的基因， 使它们进入唾液腺发育的通道。 将使用P-lacZ鉴定唾液腺标记基因 组织特异性表达β-半乳糖苷酶的转座子 包括唾液腺的模式。纯合子胚胎 将检查致死转座子插入物的表型， 改变唾液腺发育。对于非致命性插入物， 突变将通过不精确的转座子切除来诱导， 测试是否需要一个相邻的基因的发展， 唾液腺对于显示为在或 靠近一个对唾液腺发育很重要的基因， 插入片段侧翼的区域将通过质粒拯救克隆， 这些区域寻找胚胎唾液腺转录物。 为了获得基因功能的线索， 并检查与已知基因的同源性。最后， 将检查所需基因对β-半乳糖苷酶的影响 在几个增强子捕获系中表达。结果形成这些 测试将有助于确定胚胎唾液腺 发展 %%% 对早期形成模式的基因的研究 果蝇的发育非常成功， 解决了一个长期存在的谜团一个受精卵 细胞发展出复杂而有规律的模式， 是成熟胚胎的特征。这一提议是为了 将这些研究延伸到下游， 分化器官唾液腺

The embryonic development of the Drosophila salivary glands provides several advantages for analysis of the genes involved in determination and differentiation. In the ectoderm of the germ band extended embryo, the glands begin development at a defined position which suggests the involvement of several known pattern regulating genes. Differentiation then occurs within a few hours, implying that there are few steps leading from commitment to differentiation. This proposal suggests methods to identify genes acting in the salivary glands at this early stage and to order them into a pathway for salivary gland development. Salivary gland marker genes will be identified using P-lacZ transposons that express beta-galactosidase in tissue specific patterns that include the salivary glands. Embryos homozygous for lethal transposon inserts will be examined for phenotypes that alter salivary gland development. For non-lethal inserts, mutations will be induced by imprecise transposon excision to test whether an adjacent gene is required for the development of salivary glands. For some inserts that are shown to be within or near to a gene that is important for salivary gland development, regions flanking the insert will be cloned by plasmid rescue and these regions searched for embryonic salivary gland transcripts. To get clues to gene function, exonic regions will be sequenced and examined for homology with known genes. Finally, mutations in required genes will be examined for effects on beta-galactosidase expression in several enhancer trap lines. Results form these tests will help define a pathway for embryonic salivary gland development. %%% Investigations of the genes that form patterns in early drosophila development have been spectacularly successful in solving the longstanding riddle of how a single fertilized egg cell develops the intricate and regular pattern that characterizes the mature embryo. This proposal is an attempt to extend those studies downstream to the actual formation of a differentiated organ, the salivary gland.