The role of the Fox gene fd64a in Drosophila embryonic development

描述（由申请人提供）：细胞迁移发生在所有多细胞生物中。因为细胞迁移可能对生物体有益，如在发育过程中，也可能有害，如在癌症中，所以在细胞和分子水平上了解这一过程的细微差别是很重要的。这项提议的目的是确定转录因子Fd64a在果蝇胚胎发育中的作用。Fd64a是Fox转录因子家族的一员，具有多种不同的作用，包括调节参与迁移的基因的表达。fd64a在直接接触迁移唾液腺的果蝇肌肉中表达，唾液腺是研究器官中细胞迁移的理想和独特的模型系统。在缺乏fd64a的果蝇中，唾液腺表现出一系列迁移缺陷。这些初步发现导致了Fd64a调节直接唾液腺迁移的分子表达的假设。为了进一步研究fd64a在细胞迁移中的作用，Specific Aim 1的第一部分将是创建fd64a的敲除

DESCRIPTION (provided by applicant): Cell migration occurs in all multicellular organisms. Because cell migration can be beneficial to an organism, as in development, or detrimental, as in cancer, it is important to understand the nuances of this process both at the cellular and molecular level. The goal of this proposal is to determine the role of the transcription factor, Fd64a, in Drosophila embryonic development. Fd64a is a member of the Fox family of transcription factors, which have multiple different roles, including modulating the expression of genes involved in migration. fd64a is expressed in a subset of Drosophila muscles that directly contact the migrating salivary gland, an ideal and unique model system for studying cell migration in the context of an organ. In flies deficient for fd64a, the salivary gland exhibits a range of migration defects. These preliminary findings led to the hypothesis that Fd64a regulates expression of molecules that direct salivary gland migration. To further investigate the role of fd64a in cell migration, Part A of Specific Aim 1 will be to create a knock-out of fd64a by homologous recombination, and then analyzing this null allele for salivary gland migration and musculature defects. Part B of Specific Aim 1 will test if over-expression of fd64a can affect salivary gland migration. Additionally, this aim will determine if the knock-out defects can be rescued by providing wild-type fd64a function in a tissue-specific manner. Because fd64a is expressed in multiple different tissues of the Drosophila embryo, the goals of Specific Aim 2 will be to first positively identify the tissues that express fd64a and then to examine the development and morphology of these tissues in the fd64a null allele. Specific Aim 3 will investigate the downstream targets of Fd64a. Part A will use a candidate gene approach. Expression of Semaphorin 2A, a molecule known to affect migration of multiple other cell types, overlaps that of fd64a, suggesting a potential regulatory interaction. I will use in situ hybridization, protein expression, and phenotypic analysis to determine if semaphorin 2A is a viable target of Fd64a. Part B will identify other targets of Fd64a via microarray analysis comparing changes of gene expression in wild-type and fd64a-null embryos. Potential targets will be verified by in situ analysis, chromatin IP, and mutant-allele phenotype analysis. The molecular and genetic analysis of fd64a in the Drosophila embryo will provide insight into how cues provided by surrounding tissues influence migration of specific organs. This represents an important contribution to the broadening field of cell migration.