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Báo cáo sinh học: "The where and wherefore of evolutionary breakpoints"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: The where and wherefore of evolutionary breakpoints. | Journal of Biology Minireview The where and wherefore of evolutionary breakpoints David Sankoff Address Department of Mathematics and Statistics University of Ottawa 585 King Edward Avenue Ottawa K1N 6N5 Canada. Email sankoff@uottawa.ca Abstract The action in genome-level evolution lies not in the large genecontaining segments that are conserved among related species but in the breakpoint regions between these segments. Two recent papers in BMC Genomics detail the pattern of repetitive elements associated with breakpoints and the epigenetic conditions under which breakage occurs. For many years dating back to well before the genomics era there have been numerous observations and hypotheses of associations between the presence or absence of breakpoints of chromosomal evolution and prominent features of the genomic landscape telomeres centromeres recombination hotspots gene deserts or gene-rich regions isochores cytogenetically fragile sites oncological rearrangements segmental duplications transposons and other repetitive elements. Two recent papers in BMC Genomics take somewhat different tacks on this subject. Longo et al. 1 capitalize on new sequencing resources for the tammar wallaby Macropus eugenii to substantiate the links between the rapid and complex patterns of evolution of centromeric sequence and recurrent rearrangement activity in marsupials and to discover one evolutionary breakpoint region in humans that has repetitive element similarity to corresponding regions in marsupials. Lemaitre et al. 2 combine a high-resolution breakpoint localization procedure with specialized data that they have calculated or obtained on DNAse sensitivity CG content hypomethylation and replication origins 3 to dispel some of the most widespread folklore in the field. They show that propensity to breakage is not favored in gene deserts but on the contrary is closely related to transcriptional activity and DNA accessibility in a region a conclusion that lends a decidedly .