Meiosis is a modified cell division that produces four haploid nuclei from a single diploid cell in two rounds of chromosome segregation. Here, we analyze the role of Arabidopsis thaliana SUPPRESSOR WITH MORPHOGENETIC EFFECTS ON GENITALIA7 (SMG7), THREE DIVISION MUTANT1 (TDM1), and TARDY ASYNCHRONOUS MEIOSIS (TAM) in meiotic progression. SMG7 is a conserved nonsense-mediated mRNA decay factor t...

BACKGROUND In budding yeast, Sgs1 is the sole member of the RecQ family of DNA helicases. Like the human Bloom syndrome helicase (BLM), Sgs1 functions during both vegetative growth and meiosis. The sgs1 null mutant sporulates poorly and displays reduced spore viability. RESULTS We have identified novel functions for Sgs1 in meiosis. Loss of Sgs1 increases the number of axial associations, whi...

Meiosis is essential for sexually reproducing organisms, including the fission yeast Schizosaccharomyces pombe In meiosis, chromosomes replicate once in a diploid precursor cell (zygote), and then segregate twice to generate four haploid meiotic products, named spores in yeast. In S. pombe, Php4 is responsible for the transcriptional repression capability of the heteromeric CCAAT-binding factor...

BACKGROUND Anomalies in meiotic prophase I have been related to partial or total meiotic arrest. These anomalies include an abnormal synaptic process, resulting in disorders in meiotic recombination. METHODS In the present study, we analyse primary spermatocytes from 12 infertile men (four with non-obstructive azoospermia, six with oligoastenoteratozoospermia, one with astenoteratozoospermia ...

BACKGROUND Meiotic disorders result in meiotic arrest and aneuploid spermatozoa, leading to male infertility, spontaneous abortions or affected offspring. We carried out meiotic studies in an infertile male to detect meiotic nondisjunction mechanisms leading to aneuploidy in spermatogenesis. METHODS AND RESULTS Meiotic studies were performed in testicular and semen samples from a 38-year-old ...

n meiosis II, vertebrate oocytes undergo a cell cycle arrest that is maintained until fertilization, but it has been difficult to identify the factors responsible for this process. By screening a novel cDNA library, Lefebvre et al., page 603, have discovered and characterized a protein that specifically regulates meiosis II spindle integrity during arrest. The work helps to explain how the cell...

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 ...

In cells containing disrupted spindles, the spindle assembly checkpoint arrests the cell cycle in metaphase. The budding uninhibited by benzimidazole (Bub) 1, mitotic arrest-deficient (Mad) 1, and Mad2 proteins promote this checkpoint through sustained inhibition of the anaphase-promoting complex/cyclosome. Vertebrate oocytes undergoing meiotic maturation arrest in metaphase of meiosis II due t...