Science:精细测绘的黑猩猩基因组

2012-03-16 admin EurekAlert!
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 近日,国际著名杂志《科学》Science在线刊登了国外研究人员的最新研究成果“A Fine-Scale Chimpanzee Genetic Map from Population Sequencing,”,文章中,研究者精细测绘了黑猩猩的基因组。

 

一个黑猩猩的精细比例的基因图谱揭示了猿类经历与人类相比类似比率的基因重组,尽管在黑猩猩的基因组中牵涉到不同的区域。 这一重组,或者说是基因洗牌,对保持多样性及将有利的突变结合到某个生物体的遗传密码之中都是重要的。 因此,Adam Auton及其同事对10只西非黑猩猩的基因组进行了测序以发现基因重组的热点,这些热点看来是保存于所有猿类的基因组中。

他们所得到的基因图谱显示,尽管人与黑猩猩之间的基因重组率是类似的,但在这两个物种间,那些与重组事件有关的特殊位置及遗传基序则明显不同。 研究人员还观察到,被称作PDRM9的蛋白——它在人类基因组中可作为基因重组的证据——在黑猩猩的基因组中则不会同样地标示基因重组的热点。 到目前为止,这类精细比例的遗传图谱还只可从那些诸如小鼠和酵母菌等关系遥远的模式物种中获得。 但是,这一新的研究显示,类似的图谱也可以从更为复杂的、非模式的生物体中产生。

 

A Fine-Scale Chimpanzee Genetic Map from Population Sequencing

Adam Auton1,2,*, Adi Fledel-Alon3,*, Susanne Pfeifer4,*, Oliver Venn1,*, Laure Ségurel3,5, Teresa Street4, Ellen M. Leffler3, Rory Bowden1,4,6, Ivy Aneas3, John Broxholme1, Peter Humburg1, Zamin Iqbal1, Gerton Lunter1, Julian Maller1,4, Ryan D. Hernandez7, Cord Melton3, Aarti Venkat3,5, Marcelo A. Nobrega3, Ronald Bontrop8, Simon Myers1,4, Peter Donnelly1,4,†, Molly Przeworski3,5,9,†, Gil McVean1,4,†‡

 

To study the evolution of recombination rates in apes, we developed methodology to construct a fine-scale genetic map from high throughput sequence data from 10 Western Chimpanzees, Pan troglodytes verus. Compared to the human genetic map, broad-scale recombination rates tend to be conserved, but with exceptions, particularly in regions of chromosomal rearrangements and around the site of ancestral fusion in human chromosome 2. At fine-scales, chimpanzee recombination is dominated by hotspots, which show no overlap with humans even though rates are similarly elevated around CpG islands and decreased within genes. The hotspot-specifying protein PRDM9 shows extensive variation among Western Chimpanzees, and there is little evidence that any sequence motifs are enriched in hotspots. The contrasting locations of hotspots provide a natural experiment, which demonstrates the impact of recombination on base composition.