Wolfe S A, Anderson J V, Grimes S R, Stein G S, Stein J S
Research Service, Veterans Administration Medical Center, Shreveport, LA 71130.
Biochim Biophys Acta. 1989 Mar 1;1007(2):140-50. doi: 10.1016/0167-4781(89)90032-8.
A rat somatic histone H4 gene was isolated by screening a rat genomic library using a cloned cell-cycle-regulated human histone H4 gene as a probe. The somatic histone H4 gene was subcloned and the nucleotide sequence was determined. The structural organization and expression of the somatic histone H4 gene and the rat germinal histone H4t gene were compared. Although the predicted amino-acid sequences of the two histones were identical, 49 out of 102 codons differed. The leader sequence of the germinal histone H4t mRNA was 17 bases compared to 40 bases for the somatic histone H4 mRNA, and the 3' terminal sequence of the germinal histone H4t mRNA was 52 bases compared to 75 bases for the somatic histone H4 mRNA. The germinal histone H4 gene also lacked a consensus purine-rich motif which was present in the 5' noncoding region of the somatic histone H4 gene. Northern blot analyses and S1-nuclease protection analyses revealed that the germinal histone H4t and H1t genes were expressed during spermatogenesis in rat pachytene spermatocytes, and the somatic histone H4 gene was expressed only in nongerminal rat cells and tissues. The histone H4t gene was also expressed in some other rat cell types. The differences in expression of the histone H4t and H1t genes may reflect differences in transcription, differences in turnover rates of the mRNAs, or a combination of these factors.
通过使用克隆的细胞周期调控的人组蛋白H4基因作为探针筛选大鼠基因组文库，分离出了大鼠体细胞组蛋白H4基因。对该体细胞组蛋白H4基因进行亚克隆并测定了核苷酸序列。比较了体细胞组蛋白H4基因和大鼠生殖细胞组蛋白H4t基因的结构组织及表达情况。尽管两种组蛋白预测的氨基酸序列相同，但102个密码子中有49个不同。生殖细胞组蛋白H4t mRNA的前导序列为17个碱基，而体细胞组蛋白H4 mRNA的前导序列为40个碱基；生殖细胞组蛋白H4t mRNA的3'末端序列为52个碱基，而体细胞组蛋白H4 mRNA的3'末端序列为75个碱基。生殖细胞组蛋白H4基因还缺少一个存在于体细胞组蛋白H4基因5'非编码区的富含嘌呤的共有基序。Northern印迹分析和S1核酸酶保护分析表明，生殖细胞组蛋白H4t和H1t基因在大鼠粗线期精母细胞的精子发生过程中表达，而体细胞组蛋白H4基因仅在大鼠非生殖细胞和组织中表达。组蛋白H4t基因也在大鼠的其他一些细胞类型中表达。组蛋白H4t和H1t基因表达的差异可能反映了转录差异、mRNA周转速率差异或这些因素的综合作用。
