Differential contribution of the MTOR and MNK pathways to the regulation of mRNA translation in meiotic and postmeiotic mouse male germ cells.

Translation of stored mRNAs accounts for protein synthesis during the transcriptionally inactive stages of spermatogenesis. A key step in mRNA translation is the assembly of the initiation complex EIF4F, which is regulated by the MTOR (mammalian target of rapamycin) and MNK1/2 (MAP kinase-interacting kinase 1 and 2) pathways. We investigated the expression and activity of regulatory proteins of these pathways in male germ cells at different stages of differentiation.

Transcriptome analysis of differentiating spermatogonia stimulated with kit ligand.

Kit ligand (KL) is a survival factor and a mitogenic stimulus for differentiating spermatogonia. However, it is not known whether KL also plays a role in the differentiative events that lead to meiotic entry of these cells. We performed a wide genome analysis of difference in gene expression induced by treatment with KL of spermatogonia from 7-day-old mice, using gene chips spanning the whole mouse genome.

Dynamic regulation of histone H3 methylation at lysine 4 in mammalian spermatogenesis.

Spermatogenesis is a highly complex cell differentiation process that is governed by unique transcriptional regulation and massive chromatin alterations, which are required for meiosis and postmeiotic maturation. The underlying mechanisms involve alterations to the epigenetic layer, including histone modifications and incorporation of testis-specific nuclear proteins, such as histone variants and protamines. Histones can undergo methylation, acetylation, and phosphorylation among other modifications at their N-terminus, and these modifications can signal changes in chromatin structure.

PARP-1 interaction with VP1 capsid protein regulates polyomavirus early gene expression.

Poly(ADP-ribose)polymerases are involved in fundamental cellular events as well as they seem to be associated to some viral infection process. In this work, the poly(ADP-ribose)polymerase-1 (PARP-1) role in the polyomavirus life cycle has been investigated. Early viral transcription was reduced by competitive inhibitors of PARPs in Swiss 3T3 cells and almost abolished in PARP-1 knockout fibroblasts and in wild-type fibroblasts when PARP-1 was silenced by RNA interference.