DEVELOPMENTAL REGULATION IN DROSOPHILA

本建议的目的是进一步了解 转座因子P因子生物学特性及其调控 在果蝇中发现的。 P元素尤其 有趣的是，它们的转座在基因上 调节（P-M杂种发育不良综合征）和组织特异性 （转座仅发生在生殖系中，而不是在体细胞中。 组织）。 最近，我们已经证明， P元件转位在mRNA水平上受到调控 拼接 作为这些研究的继续，我们将：（1） 确定核苷酸的顺式作用序列的P 元件前mRNA转录物是生殖细胞所必需的 的特异性 (2)确定空间和发展概况 P元件生殖系特异性剪接使用β gal染色 比色法 (3)从遗传学上筛选编码 生殖系特异性RNA剪接因子。 (4)企图孤立 并维持一种果蝇生殖细胞系， 剪接P元件生殖系特异性内含子。 (5)试图 建立体外剪接系统， 种系的生化鉴定和纯化 特异性RNA剪接因子。 (6)确定哪些蛋白质产品 （7）确定P元件编码P细胞型阻遏物的基因型; P细胞型阻遏物发挥作用的机制。

The objective of this proposal is to further our understanding of the biology and regulation of P element, a transposable element found in Drosophila melanogaster. P elements are particularly interesting because their transposition is both genetically regulated (the P-M hybrid dygenesis syndrome) and tissue specific (transposition only occurs in the germline and not in somatic tissues). Recently we have shown that the germline specificity of P element transposition is regulated at the level of mRNA splicing. As a continuation of these studies we will: (1) Determine to the nucleotide which cis-acting sequences of the P element pre-mRNA transcript are required for the germline specificity. (2) Determine the spatial and developmental profile of the P element germline specific splice using a beta gal staining assay. (3) Genetically screen for mutants in the gene encoding the germline specific RNA splicing factor. (4) Attempt to isolate and maintain a Drosophila germline cell line that is capable of splicing the P element germline specific intron. (5) Attempt to establish an in vitro splicing system that will allow the biochemical identification and purification of the germline specific RNA splicing factor. (6) Identify which protein product(s) of P element encode the P cytotype repressor, (7) Determine the mechanism by which the P cytotype repressor functions.