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

Physiological role and molecular mechanism of a novel growth hormone sGH system in the chicken

新型生长激素sGH系统对鸡的生理作用及分子机制

基本信息

批准号：
16570054
负责人：
TAKEUCHI Sakae
金额：
$ 2.37万
依托单位：
OKAYAMA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16570054/
关键词：
growth hormone chicken alpha-MSH isoform physiological role POMC Pit-1 下垂体外発現転写調節

项目摘要

The chicken growth hormone (GH) gene produces two distinct GH mRNAs by alternative usage of two transcription initiation sites : the pituitary GH (p-GH) mRNA encoding circulating GH, and the extra-pituitary GH mRNA encoding a GH cytosolic isoform (s-GH). The s-GH mRNA is transcribed from the third intron of the GH gene which consists of 5 exons and 4 introns (1). Here we demonstrate for the first time that the chicken GH gene is bi-directionally transcribed in a wide variety of tissues to produce GH sense (p-GH and/or s-GH) mRNAs and multiple alternatively spliced anti-sense transcripts. Seven GH anti-sense (GH-as) transcripts with distinct exon composition were isolated by RT-PCR with RNA from embryonic chicken eyes. The 5' and 3' RACE revealed that their transcription initiates in the 3' downstream from the poly (A) site of the GH sense mRNAs, and each transcript was polyadenylated by using either of three poly (A) signals located 5' upstream from the promoter for p-GH mRNA. Those GH-as transcripts were composed of at least 5 exons, most of which overlap exons of the GH sense mRNAs. Interestingly, no open reading frame expanding over plural exons was observed in all GH-as transcripts. The RT-PCR analysis revealed that the GH sense mRNAs and the GH-as transcripts are co-expressed widely in adults and 3-day-old chickens, and the relative abundance of GH sense mRNAs and GH-as transcripts varied with tissue types. Moreover, the B-cell cell line DT40 expressed both GH sense mRNAs and GH-as transcripts, indicating that the bi-directional transcription occurs in a single cell. Protein analyses are required ; however, these findings imply the possibility that p-GH and/or s-GH expression is regulated at post-transcriptional levels by interaction between GH sense and anti-sense transcripts in the chicken.

鸡生长激素（GH）基因通过交替使用两个转录起始位点产生两种不同的GH mRNA：编码循环GH的垂体GH（p-GH）mRNA和编码GH胞质异构体（s-GH）的垂体外GH mRNA。s-GH mRNA从GH基因的第三内含子转录，其由5个外显子和4个内含子组成（1）。在这里，我们证明了第一次，鸡GH基因是双向转录在各种组织中产生GH正义（p-GH和/或s-GH）mRNA和多个选择性剪接的反义转录本。利用RT-PCR技术从鸡胚眼组织中分离到7个具有不同外显子组成的GH反义（GH-as）转录本。5'端和3'端RACE分析表明，它们的转录起始于GH正义mRNA的poly（A）位点的3'端下游，每个转录本都被位于p-GH mRNA启动子5'端上游的三个poly（A）信号中的一个多聚腺苷酸化。这些GH-as转录本由至少5个外显子组成，其中大部分与GH正义mRNA的外显子重叠。有趣的是，没有开放的阅读框架扩展到多个外显子中观察到所有GH-作为转录本。RT-PCR分析表明，GH正义mRNA和GH as转录本在成年鸡和3日龄鸡中广泛共表达，且GH正义mRNA和GH as转录本的相对丰度因组织类型而异。此外，B细胞系DT 40表达GH正义mRNA和GH-as转录物，表明在单个细胞中发生双向转录。蛋白质分析是必需的，然而，这些研究结果意味着可能性，p-GH和/或s-GH的表达在转录后水平的GH正义和反义转录本之间的相互作用，在鸡。