tailieunhanh - Báo cáo y học: " PRDM9 points the zinc finger at meiotic recombination hotspots"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: PRDM9 points the zinc finger at meiotic recombination hotspots. | Neale Genome Biology 2010 11 104 http 2010 11 2 104 w Genome Biology RESEARCH HIGHLIGHT L__ PRDM9 points the zine finger at meiotie recombination hotspots Matthew J Neale Abstract Meiotic recombination events are spread nonrandomly across eukaryotic genomes in hotspots . Recent work shows that a unique histone methyltransferase PRDM9 determines their distribution. Recombination hotspots In most organisms a central feature of meiosis is the induction of homologous recombination. In meiosis homologous recombination involves searching for homologous DNA sequences on homologous chromosomes not on sister chromatids as in somatic recombination. The result is the effective alignment of chromosome pairs a prerequisite for their subsequent accurate segregation into separate gametes and the reciprocal exchange of chromosomal regions between the two homologs to create new allele combinations recombination . These rearrangements mean that each gamete contains a unique mixture of the parental alleles. In mammals multiple lines of investigation studies of pedigree linkage disequilibrium and sperm typing show that meiotic recombination events are not uniformly distributed across the genome. Instead large areas with low median recombination rate are punctuated by discrete 1-2 kb regions called hotspots that have a much higher recombination rate reviewed in 1 . How this distribution arose and how it is maintained are topics of great interest to genome biologists. The punctate hotspot distribution observed in mammals is directly comparable to the detailed recombination maps also described in the budding yeast Saccharomyces cerevisiae where the molecular steps of meiotic recombination have been characterized most clearly 1 2 . In one way this similarity is unsurprising. All organisms seem to induce meiotic recombination by the Correspondence MRC Genome Damage and Stability Centre University of Sussex Brighton BN1 9RQ UK BioWled