权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Regulation mechanisms of transcription of sex steroidogenic enzymes during follicular growth in the chicken.

鸡卵泡生长过程中性类固醇生成酶转录的调节机制。

基本信息

批准号：
04454106
负责人：
SHIMADA Kiyoshi
金额：
$ 3.01万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1994
项目状态：
已结题

项目摘要

Concentrations of estradiol (E), testosterone (T) and progesterone (P), and levels of the 1.9-kb and 4.0-kb mRNA encoding P450_<17alpha> hydroxylase(P450_<17alpha>) and P450_<aromatase> (P450_<arom>), respectively, were measured in the isolated granulosa, theca interna and theca externa of the largest preovulatory (F1-F4) follicles of the chicken 20 h and 3 h before expected ovulation of F1. In the granulosa layr, E and T concentrations remained low throughout this period of follicular growth, whereas P concentrations were high 3 h before ovulation in F2 and F1 follicles. Estradiol levels were highest in the theca interna and externa of the amallest (F4) follicle, decreasing progressively with follicular growth. Testosterone content of theca interna and granulosa was greater in less mature F4-F2 follicles than that found in the most mature (F1) follicle, whereas theca externa contained little T.P was quantifiable in significant amounts only in granulosa tissue, peaking in F2 and F1 follicles at 3 h before ovulation, at which time plasma levels of steroids also rose significantly. P450_<17alpha> was expressed mainly in theca interna, whereas P450_<arom> mRNA levels found in theca externa refiected the pattern of E in this compartment. Expression of these two genes was very low in granulosa tissue, remaining unchanged during follicular growth. These results indicate that E and T synthesis in the chicken ovary is regulated, at least in part, at mRNA levels of P450_<17alpha> and P450_<arom> in the theca interna and theca externa layrs during follicular growth.

在鸡排卵前20 h和3 h，测定了离体最大卵泡（F1-F4）颗粒层、内膜和外膜中雌二醇（E）、睾酮（T）和孕酮（P）的浓度，以及编码P450_<17alpha>羟化酶（P450_<17alpha>）和P450_<aromatase>（P450_<arom>）的1.9 kb和4.0 kb mRNA的水平。在颗粒层中，E和T浓度在整个卵泡生长期间保持较低，而P浓度在F2和F1卵泡排卵前3小时较高。雌激素水平在最小卵泡（F4）的内膜和外膜中最高，随着卵泡的生长而逐渐降低。不太成熟的F4-F2卵泡的内膜和颗粒的睾酮含量比最成熟的（F1）卵泡中发现的更大，而外膜含有很少的T.P是可量化的，仅在颗粒组织中的显着量，在排卵前3小时在F2和F1卵泡达到峰值，此时血浆类固醇水平也显着上升。P450<17alpha>主要表达于内膜，而P450 mRNA<arom>表达于外膜，反映了E在该室的表达模式。这两个基因的表达是非常低的颗粒组织，保持不变，在卵泡生长。这些结果表明，在卵泡发育过程中，鸡卵巢E和T的合成至少部分受到内外膜层P450_和P450_mRNA水平的调节<17alpha><arom>。