1. Two distinct forms of the 64,000 Mr protein of the cleavage stimulation factor are expressed in mouse male germ cells
- Author
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Wallace, A. Michelle, Dass, Brinda, Ravnik, Stuart E., Tonk, Vijay, Jenkins, Nancy A., Gilbert, Debra J., Copeland, Neal G., and MacDOnald, Clinton C.
- Subjects
Germ cells -- Physiological aspects ,Meiosis -- Physiological aspects ,Messenger RNA -- Physiological aspects ,Proteins -- Physiological aspects ,Spermatozoa -- Physiological aspects ,X chromosome -- Physiological aspects ,Science and technology - Abstract
Polyadenylation in male germ cells differs from that in somatic cells. Many germ cell mRNAs do not contain the canonical AAUAAA in their 3[prime] ends but are efficiently polyadenylated. To determine whether the 64,000 [M.sub.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 64,000 [M.sub.r] form, we found a related [approximately equal to]70,000 [M.sub.r] protein that is abundant in testis, at low levels in brain, and undetectable in all other tissues examined. Expression of the [approximately equal to]70,000 [M.sub.r] CstF-64 was limited to meiotic spermatocytes and postmeiotic spermatids in testis. In contrast, the 64,000 [M.sub.r] form was absent from spermatocytes, suggesting that the testis-specific CstF-64 might control expression of meiosis-specific genes. To determine why the 64,000 [M.sub.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.
- Published
- 1999