EMBYONIC SALIVARY GLAND DEVELOPMENT IN DROSPHILA

果蝇胚胎唾液腺发育

基本信息

批准号：
3307782
负责人：
Steven K. Beckendorf
金额：
$ 12.17万
依托单位：
UNIVERSITY OF CALIFORNIA BERKELEY
依托单位国家：
美国
项目类别：
财政年份：
1992
资助国家：
美国
起止时间：
1992-08-01 至 1995-07-31
项目状态：
已结题

项目摘要

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 under the control of several known pattern regulating genes. Differentiation then occurs within a few hours, implying that there are few steps leading from commitment to differentiation. Recent work has suggested a model for initial salivary placode determination that implicates both anterior-posterior and dorsal-ventral pattern forming genes in this initial step in salivary development. We not want to identify two kinds of genes that this model predicts may be involved in determination, and we want to begin examining the roles of additional genes in the later stages of salivary development. Three genes that affect dorsal-ventral patterning will be tested for positive effects on placode formation and a search will be started for genes that regulate the gene, fkh, that is expressed earliest in the developing placode. Since it is clear that cell-cell interactions are important in placode formation and further development, mutants lacking or having abnormal patterns of EGF homologues like Notch or Delta will be tested for effects on placode structure or on its subsequent invagination. Since the signal for placode invagination appears to originate from the posterior margin of the placode, segment polarity genes like wingless that are necessary for the posterior part of the parasegment will be tested for effects on invagination. Two genes, Toll and Dsrc28C, that may be involved in spreading this signal to the rest of the placode will be tested by expressing them ectopically throughout the placode. A method for marking particular cells in the developing embryo will be used to determine whether additional cells join the placode after it is formed and to locate the precursors for salivary duct cells. Formation of the ducts will also be examined in embryos mutant for Serrate or for genes of the spitz group, both of which may be involved in distinguishing between gland and duct cells.

果蝇唾液腺的胚胎发育提供分析确定基因的几个优势和分化。在胚芽延伸胚胎的外胚层中，腺体在几个的控制下开始以确定的位置开发已知模式调节基因。差异化发生在几个几个小时，这意味着从承诺到分化。最近的工作提出了一个初始唾液置脚的模型确定含义前后和背腹侧的确定在唾液发育的这一第一步中形成基因的模式。我们不是想要识别该模型预测的两种基因可能是参与决心，我们想开始研究唾液发育后期的其他基因。将测试影响背腹面图案的三个基因对位置形成的积极影响，并开始搜索调节基因FKH的基因最早表达开发位置。由于很明显细胞 - 细胞相互作用是对于位置形成和进一步发展，重要的突变体缺乏或具有EGF同源物（如Notch或Delta）的异常模式将是测试了对位置结构的影响或随后的内陷。由于置换的信号似乎起源于位置的后缘，段极性基因，如翅膀无翼对于段段的后部是必需的对内陷的影响。两个基因Toll和DSRC28C，可能涉及在将此信号传播到其余部分时，将通过在整个位置中以异位表达它们。将使用一种标记发育胚中特定细胞的方法确定形成其他单元格之后是否会加入该位置并找到唾液管细胞的前体。形成在胚胎突变体中还将检查管道的锯齿状或基因 Spitz组，两者都可能参与区分腺体和导管细胞。