Comprehensive studies on meiotic behavior and pollen biology of a species are crucial for its conservation strategies. The presence bottlenecks directly or indirectly influences the reproductive success plant species. present study records chromosome number, male behavior, seed set, viability, germination in two populations Swertia thomsonii, an important medicinal Himalaya. count recorded both...

Allopolyploids have globally higher fitness than their diploid progenitors; however, by comparison, most resynthesized allopolyploids poor fertility and highly unstable genome. Elucidating the evolutionary processes promoting genome stabilization is thus essential to comprehend allopolyploid success. Using Brassica model, we mimicked speciation process of a nascent species resynthesizing allote...

Mitotic sister-chromatid cohesion (SCC) is known to depend in part on conserved proteins called adherins, which although necessary for SCC are not themselves localized between sister chromatids. We have examined mitotic DNA-repair and meiotic chromosome behavior in the Coprinus cinereus adherin mutant rad9-1. Genetic pathway analysis established that Rad9 functions in an Mre11-dependent pathway...

Meiotic crossovers are produced when programmed double-strand breaks (DSBs) are repaired by recombination from homologous chromosomes (homologues). In a wide variety of organisms, meiotic HORMA-domain proteins are required to direct DSB repair towards homologues. This inter-homologue bias is required for efficient homology search, homologue alignment, and crossover formation. HORMA-domain prote...

Meiotic recombination of sex chromosomes is thought to be repressed in organisms with heterogametic sex determination (e.g. mammalian X/Y chromosomes), due to extensive divergence and chromosomal rearrangements between the two chromosomes. However, proper segregation of sex chromosomes during meiosis requires crossing-over occurring within the pseudoautosomal regions (PAR). Recent studies revea...

Senna occidentalis (L.) Link, subarbusto pertencente à família Fabaceae, conhecido popularmente como fedegoso, é uma espécie invasora com grande potencial biológico para uso medicinal. Este estudo objetivou avaliar o índice meiótico, viabilidade polínica e composição citoquímica dos grãos de pólen S. occidentalis. Botões florais 20 indivíduos fedegoso foram coletados no município Alta Floresta,...

THE PRESENT report on the chromosomes of Neurospora crassa represents the results of observations which were confined to a period of ten weeks in the biological laboratories of Stanford University. The purpose of this study was to obtain some knowledge of nuclear and chromosome behavior in normal and mutant strains. The author realizes that no single phase of these investigations could be adequ...

It has been established that meiotic recombination and chromosome segregation are inhibited when meiotic DNA replication is blocked. Here we demonstrate that early meiotic gene (EMG) expression is also inhibited by a block in replication. Since early meiotic genes are required to promote meiotic recombination and DNA division, the low expression of these genes may contribute to the block in mei...

The genus Mesosetum is a primarily South American genus with 42 species. Mesosetum chaseae, regionally known as 'grama-do-cerrado', is abundant in the Pantanal Matogrossense (Brazil); it is a valuable resource for livestock and for environmental conservation. We collected specimens from the Nhecolandia sub-region of the Brazilian Pantanal, located in Corumbá, Mato Grosso do Sul, Brazil. We...

In budding yeast, meiotic commitment is the irreversible continuation of the developmental path of meiosis. After reaching meiotic commitment, cells finish meiosis and gametogenesis, even in the absence of the meiosis-inducing signal. In contrast, if the meiosis-inducing signal is removed and the mitosis-inducing signal is provided prior to reaching meiotic commitment, cells exit meiosis and re...