| First Author | Choi YC | Year | 1997 |
| Journal | Mamm Genome | Volume | 8 |
| Issue | 5 | Pages | 317-23 |
| PubMed ID | 9107674 | Mgi Jnum | J:39621 |
| Mgi Id | MGI:86975 | Doi | 10.1007/s003359900431 |
| Citation | Choi YC, et al. (1997) Genomic analysis of the mouse protamine 1, protamine 2, and transition protein 2 gene cluster reveals hypermethylation in expressing cells. Mamm Genome 8(5):317-23 |
| abstractText | To understand the role of chromatin structure in the expression of the mouse protamine 1, protamine 2, and transition protein 2 genes during spermatogenesis, we have examined the genomic organization of this cluster of haploid-specific genes. As seen in the human genome, protamine 2, transition protein 2, and approximately 2.8 kb of a CpG island, hereafter called CpG island-dTP2, were clustered in a small region. Methylation analyses of this region have demonstrated that i) unlike most other tissue-specific genes, the protamine 1, protamine 2, and transition protein 2 genes were located in a large methylated domain in round spermatids, the cell type where they are transcribed, ii) the protamine 1 gene was only partially methylated in somatic cells and in testes from 7-day-old mice, and iii) the approximately 2 kb upstream and downstream of the CpG island-dTP2 were only partially methylated in somatic tissues. DNase I analysis revealed the presence of at least five strong DNase I hypersensitive sites over the CpG island-dTP2 in somatic tissues, but not in germ cells, and sequence analysis indicated that the CpG island-dTP2 is homologous to a CpG island located approximately 10.6 kb downstream of the human transition protein 2 gene. Although the nature of a CpG island-dTP2 and the function of a CpG island-dTP2-containing somatic tissue-specific DNase I hypersensitive sites in close proximity to the germ cell-specific gene cluster are unclear, the open chromatin structure of the CpG island-dTP2 may be responsible for the partial methylation pattern of the flanking sequences including the transition protein 2 gene in somatic tissues. |
