1. Expression of Replication-Dependent Histone Genes in Avian Spermatids Involves an Alternate Pathway of mRNA 3′-End Formation
- Author
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Mark Groudine, Peter B. Challoner, and Stuart B. Moss
- Subjects
DNA Replication ,Male ,endocrine system ,animal structures ,Somatic cell ,Molecular Sequence Data ,Biology ,Histones ,Animals ,Gene family ,Amino Acid Sequence ,RNA, Messenger ,Molecular Biology ,Gene ,S phase ,Regulation of gene expression ,Messenger RNA ,Base Sequence ,urogenital system ,Cell Cycle ,DNA replication ,RNA ,DNA ,Cell Biology ,Spermatids ,Molecular biology ,Gene Expression Regulation ,embryonic structures ,Poly A ,Chickens ,Research Article - Abstract
In somatic cells the expression of replication-dependent histone genes is coupled to the S phase of the cell cycle. However, we have found a number of novel H2a, H2b, and H3 poly(A)+ RNA species in avian haploid round spermatids. The spermatid-specific H2a and H2b 0.8-kilobase RNAs are transcribed from a subset of the replication-dependent H2a and H2b gene families. Two cDNAs derived from the spermatid-specific H2b transcripts were isolated and sequenced. The structures of these cDNAs reveal that the spermatid-specific RNAs are identical to the 0.5-kilobase poly(A)- H2b mRNAs expressed in proliferating somatic cells, except for the addition of poly(A) at the 3' ends. The site of poly(A) addition in the spermatid-specific RNAs is located 26 to 28 nucleotides 3' of the poly(A)- H2b mRNA terminus. Thus, the hairpin structures and purine-rich elements required for the U7 small nuclear ribonucleoprotein-mediated cleavage reaction that generates the 3' ends of poly(A)- H2b mRNAs are not utilized in spermatids and are retained in the poly(A)+ H2b RNAs.
- Published
- 1989
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