在今日的BMC Genetics上，來(lái)自加州大學(xué)的科學(xué)家們發(fā)表了一篇基因組研究文章,，文章對(duì)比了非洲裔美國(guó)人和歐洲人的基因組信息,，文章首次構(gòu)建了非洲裔美國(guó)人的DNA序列拷貝數(shù)目變異copy number variant（CNV）圖譜。
拷貝數(shù)目變異也稱拷貝數(shù)目多態(tài)（copy-number polymorphism,，CNP）是一種大小介于1kb至3Mb的DNA片段的變異,，在人類基因組中廣泛分布，其覆蓋的核苷酸總數(shù)大大超過(guò)單核苷酸多態(tài)性fsingle nucle otidepolymorphisms,，SNPs）的總數(shù),，極大地豐富了基因組遺傳變異的多樣性。CNV對(duì)于物種特異的基因組構(gòu)成、物種的演化和系統(tǒng)發(fā)育以及基因組某些特定區(qū)域基因的表達(dá)和調(diào)控可能具有非常重要的生物學(xué)意義,。
該文章作者加州大學(xué)Jorge Oksenberg的神經(jīng)科學(xué)實(shí)驗(yàn)室博士后Joseph McElroy稱,，這一研究結(jié)果對(duì)非洲裔美國(guó)人多發(fā)性硬化癥病的研究具有指導(dǎo)意義。Joseph還表示,，以前對(duì)于CNV的研究都集中在白人身上,，現(xiàn)在從整個(gè)基因組上分析非洲裔美國(guó)人的CNV對(duì)非洲裔美國(guó)人具有重要的意義。
研究小組選取385名健康非洲裔美國(guó)人和435名健康白人（歐洲血統(tǒng)或是北美血統(tǒng)）來(lái)進(jìn)行研究,，經(jīng)過(guò)對(duì)比,，研究者發(fā)現(xiàn)白人組有1972個(gè)CNVs，黑人有1362個(gè)CNVs具有顯著的差異,。白人17號(hào)染色體重復(fù)拷貝數(shù)尤其多,，黑人15號(hào)染色體重復(fù)拷貝數(shù)也比較多。
研究者稱,，這些結(jié)果對(duì)某些疾病的研究具有重大的意義,，比如說(shuō)，類風(fēng)濕性關(guān)節(jié)炎,，糖尿病和Crohn氏疾病,。（生物谷Bioon.com）
生物谷推薦原始出處：
BMC Genetics 2009, 10:15doi:10.1186/1471-2156-10-15
Copy number variation in African Americans
Joseph P McElroy , Mathew R Nelson , Stacy J Caillier and Jorge R Oksenberg
Background
Copy number variants (CNVs) have been identified in several studies to be associated with complex diseases. It is important, therefore, to understand the distribution of CNVs within and among populations. This study is the first report of a CNV map in African Americans.
Results
Employing a SNP platform with greater than 500,000 SNPs, a first-generation CNV map of the African American genome was generated using DNA from 385 healthy African American individuals, and compared to a sample of 435 healthy White individuals. A total of 1362 CNVs were identified within African Americans, which included two CNV regions that were significantly different in frequency between African Americans and Whites (17q21 and 15q11). In addition, a duplication was identified in 74% of DNAs derived from cell lines that was not present in any of the whole blood derived DNAs.
Conclusions
The Affymetrix 500K array provides reliable CNV mapping information. However, using cell lines as a source of DNA may introduce artifacts. The duplication identified in high frequency in Whites and low frequency in African Americans on chromosome 17q21 reflects haplotype specific frequency differences between ancestral groups. The generation of the CNV map will be a valuable tool for identifying disease associated CNVs in African Americans.
