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作者 主題: [作業一]-Pubmed-96443001  (閱讀 5119 次)


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« 於: 二月 23, 2009, 09:21:02 am »
期刊:Nature. 2009 Feb 12;457(7231):877-81.
標題:A burst of segmental duplications in the genome of the African great ape ancestor.
作者:Marques-Bonet T, Kidd JM, Ventura M, Graves TA, Cheng Z, Hillier LW, Jiang Z, Baker C, Malfavon-Borja R, Fulton LA, Alkan C, Aksay G, Girirajan S, Siswara P, Chen L, Cardone MF, Navarro A, Mardis ER, Wilson RK, Eichler EE.

It is generally accepted that the extent of phenotypic change between human and great apes is dissonant with the rate of molecular change. Between these two groups, proteins are virtually identical, cytogenetically there are few rearrangements that distinguish ape-human chromosomes, and rates of single-base-pair change and retrotransposon activity have slowed particularly within hominid lineages when compared to rodents or monkeys. Studies of gene family evolution indicate that gene loss and gain are enriched within the primate lineage. Here, we perform a systematic analysis of duplication content of four primate genomes (macaque, orang-utan, chimpanzee and human) in an effort to understand the pattern and rates of genomic duplication during hominid evolution. We find that the ancestral branch leading to human and African great apes shows the most significant increase in duplication activity both in terms of base pairs and in terms of events. This duplication acceleration within the ancestral species is significant when compared to lineage-specific rate estimates even after accounting for copy-number polymorphism and homoplasy. We discover striking examples of recurrent and independent gene-containing duplications within the gorilla and chimpanzee that are absent in the human lineage. Our results suggest that the evolutionary properties of copy-number mutation differ significantly from other forms of genetic mutation and, in contrast to the hominid slowdown of single-base-pair mutations, there has been a genomic burst of duplication activity at this period during human evolution.

人們普遍認為的程度,表型改變人類與類人猿是不和諧率的分子變化。兩組之間,蛋白質幾乎完全相同, cytogenetically很少有重排區分猿,人類染色體和利率的單一鹼基對的變化和座子活動減緩特別是原始人系相比,囓齒動物或猴子。基因家族的研究表明,基因進化的損失並獲得豐富的靈長類動物譜系。在這裡,我們進行系統的分析,重複內容的四個靈長類動物的基因組(獼猴,紅猩猩,黑猩猩和人類)的努力來理解模式和基因組的重複率在原始人進化。我們認為,祖先的分支,導致人類和類人猿表明非洲的最顯著增加重複活動兩方面的鹼基對,並在活動。此重複加速的祖先物種具有重要意義相比,系具體率估計即使佔拷貝數多態性與homoplasy 。我們會發現,突出的例子經常和獨立的基因包含重複的大猩猩和黑猩猩有沒有在人類譜系。我們的研究結果表明,進化性質的拷貝數突變大不相同其他形式的基因突變,並在對比的是原始人放緩的單鹼基突變,出現了基因組爆裂的重複活動在此期間,人類演變。

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