To test whether missense mutations in the cancer susceptibility gene MLH1 adversely affect meiosis, we examined 14 yeast MLH1 mutations for effects on meiotic DNA transactions and gamete viability in the yeast Saccharomyces cerevisiae. Mutations analogous to those associated with hereditary nonpolyposis colorectal cancer (HNPCC) or those that reduce Mlh1p interactions with ATP or DNA all impair...

Meiosis is a process unique to the differentiation of germ cells. Retinoic acid (RA) is the key factor controlling the sex-specific timing of meiotic initiation in tetrapods; however, the role of RA in meiotic initiation in teleosts has remained unclear. In this study, the genes encoding RA synthase aldh1a2, and catabolic enzyme cyp26a1 were isolated from Nile tilapia (Oreochromis niloticus), a...

The Set1 protein of Saccharomyces cerevisiae is a histone methyltransferase (HMTase) acting on lysine 4 of histone H3. Inactivation of the SET1 gene in a diploid leads to a sporulation defect. We have studied various processes that take place during meiotic differentiation in set1delta diploid cells. The absence of Set1 leads to a delay of meiotic S-phase onset, which reflects a defect in DNA r...

The yeast C-type cyclin Ume3p/Srb11p and its cyclin-dependent kinase partner Ume5p/Srb10p repress the transcription of several genes required for meiotic recombination or meiosis I nuclear division. To relieve this repression, Srbllp is destroyed early in meiosis, prior to the first meiotic division. This report identifies two roles for Srb11p in regulating meiotic development. First, SRB11 is ...

Meiotic cells undergo a single round of DNA replication followed by two rounds of chromosome segregation (the meiotic divisions) to produce haploid gametes. Both DNA replication and chromosome segregation are similarly regulated by CDK oscillations in mitotic cells. Yet how these two events are uncoupled between the meiotic divisions is unclear. Using Saccharomyces cerevisiae, we show that meio...

The aim of this study was to analyse meiotic cells of male interspecific hybrids of the red fox (Vulpes vulpes) and the arctic fox (Alopex lagopus). To this end we determined stages of meiotic cells as well as carried out FISH analyses with probes specific to heterosomes and a TUNEL assay on synaptonemal complex preparations. The meiotic cell analysis revealed only the presence of stages of the...

EWSR1, a protein whose role in meiosis was not previously clarified detail, binds to both the recombination regulator PRDM9 and phosphorylated meiosis-specific cohesin pREC8 male meiotic cells is essential for promoting PRDM9-dependent histone methylation normal progress.

Meiosis is a key process in mammalian gametogenesis. Male infertility is frequently associated to meiotic anomalies, either due to the behaviour of constitutional chromosome abnormalities or to specific meiotic disorders. These anomalies can result in the production of chromosomally abnormal gametes or be concomitant to a meiotic arrest, both leading to the decrease in the reproductive fitness ...

BACKGROUND Birefrigent meiotic spindle in live human oocytes can be visualized by the PolScope. This study investigated the relationship between birefrigent meiotic spindle and cytoplasmic mitochondrial DNA (mtDNA) and ATP contents in in vitro matured human oocytes. METHODS Oocytes at germinal vesicle stage were collected and cultured for 24-48 h with or without the metabolic inhibitor, carbo...