Murine beta 1,4-galactosyltransferase: both the amounts and structure of the mRNA are regulated during spermatogenesis.
AUTOR(ES)
Shaper, N L
RESUMO
Previously we have shown that the gene encoding murine beta 1,4-galactosyltransferase (beta 1,4-GT; UDPgalactose:N-acetyl-D-glucosaminyl-glycopeptide 4-beta-D-galactosyltransferase, EC 2.4.1.38) is unusual in that it specifies two sets of mRNAs of about 3.9 and 4.1 kilobases (kb). Translation of the 3.9- and 4.1-kb mRNAs results in the predicted synthesis of two related membrane-bound forms of the protein of 386 amino acids (short form) and 399 amino acids (long form), respectively. In this study we have examined the expression of beta 1,4-GT during murine spermatogenesis. Spermatogonia contain a 4.1-kb transcript that is comparable in size to the beta 1,4-GT mRNA identified in somatic cells. During differentiation from spermatogonia (2n) to pachytene spermatocytes (4n), the amount of beta 1,4-GT mRNA is reduced to barely detectable levels. Continued differentiation to round spermatids (n) is coincident with a renewed production of beta 1,4-GT mRNA to levels comparable with those detected in spermatogonia. However, the characteristic 4.1-kb mRNA detected in spermatogonia is replaced by two truncated transcripts of 2.9 and 3.1 kb. By S1 nuclease analysis, the 2.9- and 3.1-kb transcripts were shown to encode the same open reading frame as the 4.1-kb transcript found in somatic cells. The shorter round spermatid transcripts arise as a consequence of the use of alternative poly(A) signals. Lastly, we show that, in direct contrast to all somatic tissues and cell lines examined to date, male germ cells synthesize only the long form of the beta 1,4-GT polypeptide.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=53352Documentos Relacionados
- Mouse testes contain two size classes of actin mRNA that are differentially expressed during spermatogenesis.
- Cell surface and Golgi pools of beta-1,4-galactosyltransferase are differentially regulated during embryonal carcinoma cell differentiation.
- Determining transcript number using the polymerase chain reaction: Pgk-2, mP2, and PGK-2 transgene mRNA levels during spermatogenesis.
- Histone mRNA concentrations are regulated at the level of transcription and mRNA degradation.
- Molecular analysis of cell surface beta-1,4-galactosyltransferase function during cell migration.