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Báo cáo sinh học: "Making sense of centromeres"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Making sense of centromeres. | J. Biol. Journal of Biology BioMed Central Research news Making sense of centromeres Pete Moore Published 31 August 2004 Journal of Biology 2004 3 16 The electronic version of this article is the complete one and can be found online at http jbiol.com content 3 4 16 2004 BioMed Central Ltd Comparative analysis of the proteins that bind exclusively at the centromere provides evidence of an evolutionary battle that may make sense of sex. At the pinched waist of each eukaryotic chromosome is a region that is both elusive and enigmatic. Despite considerable effort and multiple announcements of completed genome sequences this zone stubbornly refuses to reveal its complete sequence and what little we know of it at first sight runs counter to standard theories of evolution. The region in question is of course the centromere. Back in the 1880s scientists worked out that centromeres played a critical part in helping cells get their fair share of chromosomes during cell division and we now know that it is at these sites that spindle microtubules attach. It s not just another intriguing organelle that we would like to understand it is central to eukaryotic biology claims Steven Henikoff researcher in the Basic Sciences Division of the Fred Hutchinson Cancer Research Center Seattle and senior author of the study of centromere protein evolution published in Journal of Biology 1 see the The bottom line box for a summary of the work . In prokaryotes chromosome segregation at division occurs simultaneously with DNA replication whereas in eukaryotes the two processes occur at different points in a complex cell cycle. And while the rest of the chromosome s DNA is packaged away and consequently silenced during mitosis the centromere alone remains active in directing chromosomal movement. The bottom line Centromeric DNA is highly repetitive and is therefore difficult to sequence. It is also highly variable between species which is surprising for a region with an essential function. .