Mcm10 proteolysis initiates before the onset of M-phase

<p>Abstract</p> <p>Background</p> <p>Mcm10 protein is essential for initiation and elongation phases of replication. Human cells proteolyze Mcm10 during mitosis, presumably to ensure a single round of replication. It has been proposed that anaphase promoting complex ubiquitinates Mcm10 in late M and early G₁phases.</p> <p>Results</p> <p>In contrast to the previous work, we report that the degradation of Mcm10 is initiated at the onset of mitosis. Immunoblotting and immunofluorescence assays display that Mcm10 levels are low in all phases of mitosis. We report that Mcm10 degradation is not dependent on anaphase promoting complex. Further, the proteolysis in M-phase can be independently mediated by non-overlapping regions of Mcm10, apparently employing a redundant mechanism to ensure downregulation.</p> <p>Conclusions</p> <p>It is believed that the proteolysis of Mcm10 during mitosis is a vital mechanism to prevent aberrant initiation of replication and the present study describes the regulation of Mcm10 during this phase of the cell-cycle.</p

Ichthyofaunal diversity of Chilika Lake, Odisha, India: an inventory, assessment of biodiversity status and comprehensive systematic checklist (1916-2014)

Chilika Lake, an assemblage of marine, brackish and freshwater ecosystems, on the east coast of India is a designated Ramsar site and a biodiversity hotspot. Intensive ichthyofaunal inventories and biodiversity assessments were carried out during 2000–2014 and documented 317 species belonging to 207 genera, in 88 families and 23 orders, including two endemic (Gobiidae) and one exotic cichlid species (Oreochromis mossambicus). In total, 255 collections (178 collections of previously recorded species and 77 that represent newly recorded species) were made during a post-restoration survey accounting for 80.44% retrieval of historically documented species. This paper presents an updated and comprehensive checklist of the lake’s ichthyofauna (1916–2014), which is comprised of 278 food fishes, 271 (85.49%) migratory and 46 (14.51%) are resident species indicating that the lake fishery is largely migratory species-dependent. An account of faunal characteristics for 129 commercially important species is provided. The checklist also documents 48 threatened species and 103 species under different categories of conservation status

The Attitute of Asian and African States toward the evolution of the United Nations International Law Commission and the formulation of rules on the Law of Treaties

Doctorat en sciences sociales, politiques et économiquesinfo:eu-repo/semantics/nonPublishe

The Attitute of Asian and African States toward the evolution of the United Nations International Law Commission and the formulation of rules on the Law of Treaties

Doctorat en sciences sociales, politiques et économiquesinfo:eu-repo/semantics/nonPublishe

Mechanistic View and Genetic Control of DNA Recombination during Meiosis

International audienceMeiotic recombination is essential for fertility and allelic shuffling. Canonical recombination models fail to capture the observed complexity of meiotic recombinants. Here, by combining genome-wide meiotic heteroduplex DNA patterns with meiotic DNA double-strand break (DSB) sites, we show that part of this complexity results from frequent template switching during synthesis-dependent strand annealing that yields noncrossovers and from branch migration of double Holliday junction (dHJ)-containing intermediates that mainly yield crossovers. This complexity also results from asymmetric positioning of crossover intermediates relative to the initiating DSB and Msh2-independent conversions promoted by the suspected dHJ resolvase Mlh1-3 as well as Exo1 and Sgs1. Finally, we show that dHJ resolution is biased toward cleavage of the pair of strands containing newly synthesized DNA near the junctions and that this bias can be decoupled from the cross-over-biased dHJ resolution. These properties are likely conserved in eukaryotes containing ZMM proteins, which includes mammals

Concerted action of the MutL beta heterodimer and Mer3 helicase regulates the global extent of meiotic gene conversion

Gene conversions resulting from meiotic recombination are critical in shaping genome diversification and evolution. How the extent of gene conversions is regulated is unknown. Here we show that the budding yeast mismatch repair related MutL beta complex, Mlh1-Mlh2, specifically inter acts with the conserved meiotic Mer3 helicase, which recruits it to recombination hotspots, independently of mismatch recognition. This recruitment is essential to limit gene conversion tract lengths genome-wide, without affecting cross over formation. Contrary to expectations, Mer3 helicase activity, proposed to extend the displacement loop (D-loop) recombination intermediate, does not influence the length of gene conversion events, revealing non-catalytical roles of Mer3. In addition, both purified Mer3 and MutL beta preferentially recognize D-loops, providing a mechanism for limiting gene conversion in vivo. These findings show that MutL beta is an integral part of a new regulatory step of meiotic recombination, which has implications to prevent rapid allele fixation and hotspot erosion in populations