Open AccessTwo distinct forms of the 64,000 M r protein of the cleavage stimulation factor are expressed in mouse male germ cells
Author(s) -
Andrew Wallace,
Brinda Dass,
Stuart E. Ravnik,
Vijay Tonk,
Nancy A. Jenkins,
Debra J. Gilbert,
Neal G. Copeland,
Clinton C. MacDonald
Publication year - 1999
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.96.12.6763
Subject(s) - biology , cleavage stimulation factor , polyadenylation , meiosis , somatic cell , microbiology and biotechnology , cleavage (geology) , cleavage and polyadenylation specificity factor , gene , rna binding protein , genetics , gene expression , messenger rna , paleontology , fracture (geology)
Polyadenylation in male germ cells differs from that in somatic cells. Many germ cell mRNAs do not contain the canonical AAUAAA in their 3′ ends but are efficiently polyadenylated. To determine whether the 64,000M r protein of the cleavage stimulation factor (CstF-64) is altered in male germ cells, we examined its expression in mouse testis. In addition to the 64,000M r form, we found a related ≈70,000M r protein that is abundant in testis, at low levels in brain, and undetectable in all other tissues examined. Expression of the ≈70,000M r CstF-64 was limited to meiotic spermatocytes and postmeiotic spermatids in testis. In contrast, the 64,000M r form was absent from spermatocytes, suggesting that the testis-specific CstF-64 might control expression of meiosis-specific genes. To determine why the 64,000M r CstF-64 is not expressed in spermatocytes, we mapped its chromosomal location to the X chromosome in both mouse and human. CstF-64 may, therefore, be absent in spermatocytes because the X chromosome is inactivated during male meiosis. By extension, the testis-specific CstF-64 may be expressed from an autosomal homolog of the X chromosomal gene.