Developmental Differences in Brain Androgen Synthesis

描述（由申请人提供）：斑胸草雀的鸣叫系统包括： 性二形核。早期雌激素治疗使端脑型 在遗传雌性中的歌核，但阻断雌激素不会使雄性细胞去雄性化 这些细胞核的基因。研究表明， 一种大脑固有的遗传因素是歌曲男性化模式的基础 系统组织最近，性别差异已经被发现， 转录水平的17 α羟化酶（β 17），酶，使 雄激素，在发育中的斑胸草雀的端脑中。据推测 GYP17的表达贯穿了歌曲的类固醇敏感期， 系统的发展，并分布在附近的宋核。这将是 使用原位杂交进行研究。据推测， CYP17 mRNA水平反映了蛋白质介导的 转录调控DNA序列从启动子区的17 基因将通过筛选cDNA文库，进行5？种族和 筛选斑胸草雀基因组文库。这代表了第一步， 确定差异调节BMP17转录的因子， 正在发育的雄性和雌性斑胸草雀的端脑他们还将 表明在其他哺乳动物中雄激素合成潜在调节机制 物种，包括人类。

DESCRIPTION (provided by applicant): The zebra finch song system consists of sexually dimorphic nuclei. Early estrogen treatment masculinizes telencephalic song nuclei in genetic females, but blocking estrogen does not demasculinize these nuclei in genetic males. Studies have suggested that the existence of a genetic factor intrinsic to the brain underlies the masculine pattern of song system organization. Recently, a sex difference has been seen in transcriptional levels of 17 alpha hydroxylase (CYP 17), the enzyme that makes androgen, in the telencephalon of developing zebra finches. It is hypothesized that GYP 17 expression extends through the steroid sensitive period of song system development, and is distributed near the song nuclei. This will be investigated using in situ hybridization. It is hypothesized that the different levels of CYP17 mRNA reflect sex differences in protein-mediated transcriptional regulation. DNA sequence from the promoter region of the CYP 17 gene will be determined by screening a cDNA library, performing 5? RACE, and screening a zebra finch genomic library. This represents a first step in identifying the factors that differentially regulate CYP 17 transcription in the telencephalon of developing male and female zebra finch. They will also indicate potential regulatory mechanisms for androgen synthesis in other species, including humans.