生物谷援引:据2007年7月31日netindia123网站报告,美国科罗拉多卫生科学中心大学和斯坦福大学联合研究小组公布了一项大规模基因组研究的结果,该研究旨在调查10种灵长类动物(包括人类在内)之间基因复制数量的差异。该研究全面调查了不同种系灵长类动物的基因和基因族,它们在长达6000万年的进化时间里,曾经历过主要基因复制数量的扩张和收缩。
为了调查这10种灵长类动物之间基因复制数量的差异,科研人员使用了带有24000多个人类DAN的微阵列来开展对比性基因杂交试验。接着,他们把人类的DNA样本与其它9种灵长类动物的DNA样本进行对比,这9种灵长类动物分别为:黑猩猩、大猩猩、倭黑猩猩、猩猩、长臂猿、短尾猿、狒狒、狨和狐猴。这种对比使他们识别出了一些特殊的基因和基因族,这些基因和基因族在进化过程中曾经历过种系特异性基因复制数量的增加和减少。
科学家声称,他们发现“许多已识别出的基因很可能与造就人类和其它9种灵长类动物的种系遗传特点有重要关系”。为了阐明这一潜在的可能性,科学家重点强调了几种表现出惊人的种系特异性差异的基因族。其中一个基因称为AQP7,它的人类种系特异性基因复制数量的扩张可以解释为什么人类进化出了长跑的耐力。AQP7的全称为水通道蛋白-7(aquaporin 7),它的作用是穿过细胞膜传送水和甘油。科研人员撰写的这篇研究论文发表在《基因组研究》杂志网络版上。因此,在人类进行剧烈运动期间,AQP7将捉使人体动用糖原(即能量)贮备。它同时还可以帮助人类通过出汗来排除多余的热量。
科学家称,他们还发现基因复制数量的巨大差异与认知、繁殖、免疫和遗传病敏感性有潜在的关系。詹姆士.西克拉教授说:“灵长类动物大约于9000万年首次出现在地球上,而今,大约存在300种不同种类的灵长类动物。灵长类动物进化的主要基因推动力之一是基因复制”。他说:“据我所知,这项研究是迄今为止对人类和灵长类动物基因复制数量变化最全面的评估。”(中国科技信息网Chinainfo)
原始出处:
Published online before print July 31, 2007
Genome Research, DOI: 10.1101/gr.6557307
Gene copy number variation spanning 60 million years of human and primate evolution
Laura Dumas1, Young H. Kim2, Anis Karimpour-Fard3, Michael Cox1,4,5, Janet Hopkins1,4,5, Jonathan R. Pollack2, and James M. Sikela1,4,5,6
1 Human Medical Genetics Program, University of Colorado at Denver and Health Sciences Center, Aurora, Colorado 80045, USA; 2 Department of Pathology, Stanford University, Stanford, California 94305, USA; 3 Department of Preventative Medicine and Biometrics, University of Colorado at Denver and Health Sciences Center, Aurora, Colorado 80045, USA; 4 Neuroscience Program, University of Colorado at Denver and Health Sciences Center, Aurora, Colorado 80045, USA; 5 Department of Pharmacology, University of Colorado at Denver and Health Sciences Center, Aurora, Colorado 80045, USA
Given the evolutionary importance of gene duplication to the emergence of species-specific traits, we have extended the application of cDNA array-based comparative genomic hybridization (aCGH) to survey gene duplications and losses genome-wide across 10 primate species, including human. Using human cDNA arrays that contained 41,126 cDNAs, corresponding to 24,473 unique human genes, we identified 4159 genes that likely represent most of the major lineage-specific gene copy number gains and losses that have occurred in these species over the past 60 million years. We analyzed 1,233,780 gene-to-gene data points and found that gene gains typically outnumbered losses (ratio of gains/losses = 2.34) and these frequently cluster in complex and dynamic genomic regions that are likely to serve as gene nurseries. Almost one-third of all human genes (6696) exhibit an aCGH- predicted change in copy number in one or more of these species, and within-species gene amplification is also evident. Many of the genes identified here are likely to be important to lineage-specific traits including, for example, human-specific duplications of the AQP7 gene, which represent intriguing candidates to underlie the key physiological adaptations in thermoregulation and energy utilization that permitted human endurance running.