“Telomere-led chromosome movements are a conserved feature

“Telomere-led chromosome movements are a conserved feature of meiosis I (MI) prophase. Several roles have been proposed for such chromosome motion, including promoting homolog pairing and LY2606368 ic50 removing inappropriate chromosomal interactions. Here, we provide evidence in

budding yeast that rapid chromosome movements affect homolog pairing and recombination. We found that csm4 Delta strains, which are defective for telomere-led chromosome movements, show defects in homolog pairing as measured in a “one-dot/two-dot tetR-GFP” assay; however, pairing in csm4 Delta eventually reaches near wild-type (WT) levels. Charged-to-alanine scanning mutagenesis of CSM4 yielded one allele, csm4-3, that confers a csm4 Delta-like delay in meiotic prophase but promotes high spore viability. The meiotic delay in csm4-3 strains is essential for spore viability because a null mutation (rad17 Delta) in the Rad17 checkpoint protein suppresses the delay but confers selleck chemicals llc a severe spore viability defect. csm4-3 mutants show a general defect in chromosome motion but an intermediate defect in chromosome pairing. Chromosome velocity analysis in live cells showed that while average chromosome velocity was strongly

reduced in csm4-3, chromosomes in this mutant displayed occasional rapid movements. Lastly, we observed that spo11 mutants displaying lower levels of meiosis-induced double-strand breaks showed higher spore viability in the presence of the csm4-3 mutation compared to csm4 Delta. On the basis of these observations, we propose that during meiotic prophase the presence of occasional fast moving chromosomes over an extended period of time is sufficient to promote WT levels of recombination and high spore viability; however, sustained and rapid chromosome movements are required to prevent a checkpoint response selleck and promote efficient meiotic progression.”
“Theileria sp. MK in sheep and goats were detected

first time by polymerase chain reaction (PCR) and detection limit of PCR and reverse line blotting (RLB) were compared. A part of 18S ssu rRNA gene was amplified from blood samples that were taken from sheep and goats naturally infected with Theileria sp. MK by PCR. Detection limit of both PCR and RLB methods was one infected cell in 10(7) sheep erythrocytes. Nine hundred twenty field samples that had been tested previously by RLB were evaluated by the PCR assay. As found by RLB previously, 12 of 920 (1.30%) samples were detected as positive by PCR. Two positive PCR products, one of which was from sheep and the other from goat, were sequenced. These sequences were identical to the reported nucleotide sequence of Theileria sp. MK. It is concluded that the PCR described in this study will be useful for epidemiological studies and for discrimination between Theileria sp. MK and other Theileria species. In addition, PCR has superiority over RLB because of its ease of use and time period required.

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