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REGULATION OF GENE EXPRESSION DURING SPERMATOGENESIS

精子发生过程中基因表达的调控

基本信息

批准号：
04454021
负责人：
KATAGIRI Chiaki
金额：
$ 4.48万
依托单位：
HOKKAIDO 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

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04454021/
关键词：
SPERM NUCLEAR BASIC PROTEINS Xenopus laevis SPERMATOGENESIS cDNA AMINO ACID SEQUENCE GENE STRUCTURE GENOMIC ANALYSIS TRANSCRIPTIONAL REGULATION 両生類塩基配列ゲノミックDNA 卵膜ライシン cDNAライブラリー

项目摘要

Nuclear basic proteins of an anuran amphibian Xenopus laevis consist of 6 sperm specific proteins (SPs 1-6) in addition to somatic core histones. Analyzes based on cDNAs indicated that SP4 and SP5 each comprising 78- and 74 amino acids have properties intermediate between typical protamines and somatic histones, and are present in a ratio of 5/1 (SP4/SP5). Construction of restriction maps based on Southern blot analyzes of genomic DNA revealed the presence of a total of five SP4 genes which are arranged in a tandemly repeated array forming a cluster of simple multigenes per haploid genome, over a range of 20kbp. Each gene contains an intron, typical TATA and CCAAT boxes in the 5'-flanking region, and a polyadenylation signal in the 3'-flanking region. In addition, there are three regions of extensive sequence homology within the upstream non-coding region among three SP4 genes which were totally seuquenced for over 10kbp, suggesting its possible relevance to the expression of these genes at a particular phase of spermatogenesis and/or in testis. Among the five tandemly arranged genes, the one located at the most upstream position differed from others in possessing a single base substitution which could give rise to an amino acid replacement of Ala to Ser. The presence of this particular variant of SP4 was confirmed by reversed-phase HPLC fractionation of sperm nuclear proteins, and its relative amout to SP4 was 1/4, reflecting the relative amount of relevant genes. Similar measurements of the amounts of protein and mRNA,and the number of genes for SP5 relative to SP4 indicated that in all these parameters the ratio was consistently 1/5 (SP5/SP4). Thus the deposition of different amounts of 'SP5 and SP4 (including its variant) in sperm nuclei reflects the relative number of these genes in the genome.

无尾目两栖动物非洲爪蟾的核碱性蛋白除体细胞核心组蛋白外还包含 6 种精子特异性蛋白 (SP 1-6)。基于cDNA的分析表明，分别包含78个和74个氨基酸的SP4和SP5具有介于典型鱼精蛋白和体细胞组蛋白之间的特性，并且以5/1(SP4/SP5)的比例存在。基于基因组 DNA 的 Southern 印迹分析构建的限制性图谱揭示了总共 5 个 SP4 基因的存在，这些基因排列成串联重复阵列，形成每个单倍体基因组的简单多基因簇，范围超过 20kbp。每个基因都包含一个内含子、5' 侧翼区域中的典型 TATA 和 CCAAT 盒以及 3' 侧翼区域中的聚腺苷酸化信号。此外，在三个SP4基因的上游非编码区内存在三个具有广泛序列同源性的区域，这三个SP4基因的总测序长度超过10kbp，表明其可能与这些基因在精子发生和/或睾丸中的特定阶段的表达相关。在这五个串联排列的基因中，位于最上游位置的基因与其他基因的不同之处在于具有单个碱基取代，可以导致氨基酸从Ala替换为Ser。通过精子核蛋白的反相HPLC分级分离证实了SP4的这种特殊变体的存在，其与SP4的相对量为1/4，反映了相关基因的相对量。对蛋白质和 mRNA 的量以及 SP5 相对于 SP4 的基因数量的类似测量表明，在所有这些参数中，比率始终为 1/5 (SP5/SP4)。因此，精子核中不同数量的'SP5和SP4（包括其变体）的沉积反映了这些基因在基因组中的相对数量。