BACKGROUND Meiosis is a process of universal importance in eukaryotic organisms, generating variation in the heritable haploid genome by recombination and re-assortment of chromosomes. The intranuclear movement of chromosomes is expected to achieve pairing and recombination of homologous chromosomes during meiosis. Meiosis in the budding yeast Saccharomyces cerevisiae has been extensively studi...

Centromere protein A (CENP-A) is a histone H3 variant that defines centromeric chromatin and essential for centromere function. In most eukaryotes, CENP-A-containing epigenetically maintained, identity inherited from one cell cycle to the next. germ line of holocentric nematode Caenorhabditis elegans , this inheritance disrupted. CENP-A removed at mitosis-to-meiosis transition reestablished on ...

Production of haploid gametes from diploid progenitor cells is mediated by a specialized cell division, meiosis, where two divisions, meiosis I and II, follow a single S phase. Errors in progression from meiosis I to meiosis II lead to aneuploid and polyploid gametes, but the regulatory mechanisms controlling this transition are poorly understood. Here, we demonstrate that the conserved kinase ...

Meiosis, like mitosis depends on the activity of the mitotic Cyclin dependent kinase, Cdk1 and its cyclin partners. Here we examine the specific requirements for the three mitotic cyclins, A, B and B3 in meiosis of Drosophila melanogaster We find that all three cyclins contribute redundantly to nuclear envelope breakdown, though Cyclin A appears to make the most important individual contributio...

Progesterone induces fully grown, stage VI, Xenopus oocytes to pass through meiosis I and arrest in metaphase of meiosis II. Protein synthesis is required twice in this process: in order to activate maturation promoting factor (MPF) which induces meiosis I, and then again after the completion of meiosis I to reactivate MPF in order to induce meiosis II. We have used antisense oligonucleotides t...

Phospholipase D (PLD) enzymes catalyze the hydrolysis of phosphatidylcholine and are involved in membrane trafficking and cytoskeletal reorganization. The Saccharomyces cerevisiae SPO14 gene encodes a PLD that is essential for meiosis. We have analyzed the role of PLD in meiosis by examining two mutant proteins, one with a point mutation in a conserved residue (Spo14pK--> H) and one with an ami...

BACKGROUND: In most organisms proper reductional chromosome segregation during meiosis I is strongly correlated with the presence of crossover recombination structures (chiasmata); recombination deficient mutants lack crossovers and suffer meiosis I nondisjunction. We report that these functions are separable in the fission yeast Schizosaccharomyces pombe. RESULTS: Intron mapping and expression...

Sexual reproduction in eukaryotes is accomplished by meiosis, a complex and specialized process of cell division that results in haploid cells (e.g., gametes). The stereotypical reductive division in meiosis is a major evolutionary innovation in eukaryotic cells, and delineating its history is key to understanding the evolution of sex. Meiosis arose early in eukaryotic evolution, but when and h...

ABSTRACT Heterochromatin-related epigenetic mechanisms, such as DNA methylation, facilitate pairing of homologous chromosomes during the meiotic prophase mammalian spermatogenesis. In pro-spermatogonia, de novo methylation plays a key role in completing and initiating division. However, maintenance regulation meiosis, especially adult, is not well understood. Here, we reveal that NP95 (also kno...

Triploid oysters were induced using cytochalasin B upon retention of either the first (meiosis I triploids) or the second (meiosis II triploids) polar body in embryos from a single cohort derived from mixed parentage. Allozyme and microsatellite assays enabled the confirmation of both parentage and triploidy status in each oyster. Comparison of meiosis I triploids, meiosis II triploids and dipl...