Prolactin-Inducible Genes of Pigeon Crop

催乳素（PRL）的作用特征如下： 细胞分化和基因表达的变化， 这是差异化的基础。 这项研究是针对 为了理解诱导基因表达的改变， 乳鸽生殖器组织中的催乳素。 这个模型特别有用 因为组织组织和发育相对简单， 催乳素引起的变化是深刻而迅速的。 使用了各种分子方法。 特异性催乳素诱导 基因产物已经被我们通过在体内和在体外鉴定， 体外蛋白质合成，克隆，差异 杂交、免疫化学探针和与已知的 基因. 催乳素诱导基因表达的机制 将是本提案所述实验的主题。 将对来自作物的主要PRL诱导型cDNA进行测序， 完成研究可能的关系，这些基因与基因 已知的功能。 这些数据在以后也会很有用。 预测参与调控的序列， 基因. 核径流转录测定和mRNA周转 测量将用于确定是否PRL的调节- 可诱导的mRNA主要在转录或后 转录水平。 根据迄今为止的数据，预计 大部分调节将是转录后的。 如果是这样的话， 负责控制的因素的生物化学性质 PRL诱导的mRNA衰减将通过重建以下两种蛋白质来研究： 具有胞质因子的天然或克隆的PRL诱导型转录物 从作物组织中提取。 产品的衰变将通过以下两种方法测量： 末端标记转录物的杂交或电泳。 如果 转录是PRL控制的主要机制， 一个或多个PRL诱导基因的结构将被 通过Southern分析、基因组克隆、S1作图和 测序 拟议的实验将提供一个了解 催乳素刺激作物组织的机制和底物 模型，并将有助于对 这一重要激素的作用机制。

The actions of prolactin (PRL) are characterized by cellular differentiation and the changes of gene expression that underlie that differentiation. This research is directed toward understanding the induction of altered gene expression in pigeon crop tissue by prolactin. This model is especially useful because the tissue organization and development is relatively simple, and the changes prolactin induces are profound and rapid. Various molecular approaches are used. Specific prolactin-induced gene products have been identified by us through in vivo and in vitro protein synthesis, cloning, differential hybridization, immunochemical probes, and hybridization with known genes. The mechanisms responsible for PRL-induced gene expression will be the subject of the experiments described in this proposal. Sequencing of the major PRL-inducible cDNAs from the crop will be completed to examine possible relationships of these genes with genes of known function. These data will also be useful later in making predictions about sequences involved in the regulation of the genes. Nuclear run-off transcription assays and mRNA turnover measurements will be used to determine whether the regulation of PRL- inducible mRNAs is primarily at a transcriptional or post- transcriptional level. Based on data thus far it is expected that a large part of the regulation will be post-transcriptional. If so, the biochemical nature of the factors responsible for controlling PRL-inducible mRNA decay will be studied by reconstituting either native or cloned PRL-inducible transcripts with cytosolic factors from crop tissues. Decay of the products will be measured by either hybridization or electrophoresis of end-labelled transcripts. If transcription is the primary mechanism of PRL control, the genomic structure of one or more of the PRL-inducible genes will be determined by Southern analysis, genomic cloning, S1 mapping and sequencing. The proposed experiments will provide an understanding of the mechanisms and substrates of prolactin stimulation in the crop tissue model, and will contribute to the general understanding of the mechanism of action of this important hormone.