In the yeast Saccharomyces cerevisiae, meiotic recombination is initiated by double-strand DNA breaks (DSBs). Meiotic DSBs occur at relatively high frequencies in some genomic regions (hotspots) and relatively low frequencies in others (coldspots). We used DNA microarrays to estimate variation in the level of nearby meiotic DSBs for all 6,200 yeast genes. Hotspots were nonrandomly associated wi...

Vochysia divergens Pohl. is a tree species used in folk medicine, landscaping and reforestation. Its occurrence recorded the Amazon, Pantanal Cerrado biomes and, despite these uses its wide distribution, studies regarding reproductive aspects are nonexistent. Thus, this research aimed to study morphology of pollen V. evaluate viability meiotic index, as well compare descriptors two natural popu...

Meiotic recombination safeguards proper segregation of homologous chromosomes into gametes, affects genetic variation within species, and contributes to meiotic chromosome recognition, pairing and synapsis. The Prdm9 gene has a dual role, it controls meiotic recombination by determining the genomic position of crossover hotspots and, in infertile hybrids of house mouse subspecies Mus m. musculu...

Holliday junctions (HJs) are cruciform DNA structures that are created during recombination events. It is a matter of considerable importance to determine the resolvase(s) that promote resolution of these structures. We previously reported that C. elegans GEN-1 is a symmetrically cleaving HJ resolving enzyme required for recombinational repair, but we could not find an overt role in meiotic rec...

Signals that promote germ cell self-renewal by preventing premature meiotic entry are well understood. However, signals that control mitotic proliferation to promote meiotic differentiation have not been well characterized. In Caenorhabditis elegans, GLP-1 Notch signalling promotes the proliferative fate by preventing premature meiotic entry. The germline niche cell, which is the source of the ...

I T has been known since the early work of PLOUGH (1917, 1921) that alterations in temperature can increase recombination frequencies in females of Drosophila melanogaster. Two distinct, yet related, problems have arisen from such studies. First, does the additional frequency of crossing over represent gonial or meiotic events, or both? Second, does temperature act at the time of crossing over ...