tailieunhanh - Báo cáo y học: "Why genes persist in organelle genomes"

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: Why genes persist in organelle genomes. | Opinion Why genes persist in organelle genomes Daniel O Daley and James Whelan Addresses Department of Biochemistry and Biophysics Stockholm University S106 91 Sweden. fPlant Molecular Biology Group School of Biomedical and Chemical Science University of Western Australia Nedlands 6009 Western Australia Australia. Correspondence James Whelan. E-mail seamus@ Published 29 April 2005 Genome Biology 2005 6 110 doi gb-2005-6-5-110 The electronic version of this article is the complete one and can be found online at http 2005 6 5 110 2005 BioMed Central Ltd Abstract Mitochondria and plastids including chloroplasts have a small but vital genetic coding capacity but what are the properties of some genes that dictate that they must remain encoded in organelles The sequencing of both organelle and nuclear genomes from phylogenetically diverse species will help us to infer how these genomes have evolved and the forces that have shaped them. Recent findings of high rates of transfer of organelle DNA to the nucleus 1 and of high rates of functional gene transfer from organelles to the nucleus 2-5 demonstrate that the endosymbiotic origin of organelles was a major determinant in defining eukaryotic nuclear genomes and was probably a defining event for the formation of the eukaryotic cell 1 6 . Clearly there is an evolutionary pressure to centralize genetic information in the nucleus but the forces behind this transfer are not obvious. Muller s ratchet -the unidirectional process of building up mutations in an asexually reproducing population - is one commonly suggested hypothesis to account for this centralization but is limited in its ability to explain more recent gene transfer events reviewed in 5 . But despite a wealth of information it is still not clear from genome sequencing why some genes remain encoded in organelles such as mitochondria and chloroplasts. A recent study in yeast 7 indicated that an astonishing 25 of the .