Molecular mechanisms of oviposition control

产卵控制的分子机制

基本信息

批准号：
04044079
负责人：
SHIMADA Kiyoshi
金额：
$ 5.89万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

项目摘要

We have proposed a hypothesis for oviposition mechanism as follows ; ovarian prostaglandin is released into peripheral plasma to stimulating uterine contractions, which in turn, triggers AVT release from the neurohypophysis. The present project was conducted to prove the above hypothesis by providing following evidence on the molecular basis.1. Prostaglandins were produced in the theca layers of the largest pre- and postovulatory follicles and tissue PG level was highest with concurrent increase in plasma PGF concentration immediately before oviposition. Ovarian-oviposition inducing factor was identified as PG by HPLC analysis. These results indicate that ovarian PG plays a pivotal role in the regulation of oviposition.2. Plasma AVT concentration also increased at the time of oviposition. AVT was released in response to uterine contractions but this increase was suppressed by indomethacin treatment which delayed oviposition. Immunocytochemical studies revealed that AVT-containing neuro … More ns were detected at the preoptic region and superficial area of the third ventricle. AVT cDNA was cloned and its base sequence was determined. Using the 562-base cDNA as a probe Northern hybridization analysis detected about 700 bases of AVT mRNA in the hypothalamus. The mRNA levels increased 4-fold after 4-day of water deprivation. Analysis of in situ hybridization revealed AVT mRNA localized in the periventricular nuclei of the hypothalamus.3. Finally, the project of cloning of AVT receptor cDNA is stil in progress but solubilized fraction of AVT receptor of the chicken uterus was purified, electophoresed and this fraction was isolated. At present, amino acid sequencing is under an investigation and will be used for primers in PCR cloning to isolate the gene. On the basis of amino acid sequences of homologous region of human oxytocin receptor cDNA and rat arginine vasoporessin receptor, primers were synthesized for RT-PCR of chicken uterus RNA. The 452-bases RT-PCR cDNA product was used as a probe for Northern hybridization of the chicken uterus. Hybridizable mRNA species of 5.6, 4.6 and 2.1 kd were identified as AVT receptor mRNA. Less

我们提出了如下的产卵机制假设：卵巢前列腺素释放到外周血浆中，刺激子宫收缩，进而触发神经垂体释放 AVT。本项目旨在通过提供以下证据来证明上述假设。分子基础1.排卵前和排卵后最大的卵泡膜层中产生前列腺素，组织PG水平最高，同时在排卵前血浆PGF浓度增加。通过HPLC分析确定卵巢排卵诱导因子为PG。这些结果表明卵巢PG在排卵调节中发挥着关键作用。2．排卵时血浆AVT浓度也随着子宫收缩而升高。但这种增加被吲哚美辛治疗所抑制，该治疗延迟了产卵，免疫细胞化学研究表明，在视前检测到含有 AVT 的神经。克隆了第三脑室的AVT cDNA并测定了其碱基序列，使用Northern杂交分析检测到下丘脑中约700个碱基的AVT mRNA水平增加了4。原位杂交分析显示AVT mRNA定位于下丘脑的室周核中4倍后。3． AVT受体cDNA仍在研究中，但鸡子宫AVT受体的可溶部分已被纯化、电泳并被分离。目前，氨基酸测序正在研究中，并将用作PCR克隆的引物以分离该基因。根据人催产素受体cDNA和大鼠精氨酸血管加压素受体同源区的氨基酸序列，合成了鸡子宫RT-PCR引物。 RNA。452个碱基的RT-PCR cDNA产物用作5.6、4.6和2.1kd的可杂交mRNA种类的探针，被鉴定为AVT受体mRNA。