近期一项发表于《自然》杂志网络版的最新遗传分析表明,从法国的狮子狗到德国的牧羊犬,所有的家狗都起源于中东,而非之前研究所认为的东亚。
相关链接:BMC Biology:狗起源于中东
研究所指的中东地区也就是俗称的“新月沃土”,包括中东两河流域及附近一连串肥沃的土地,位于今日的以色列、黎巴嫩、约旦部分地区以及伊拉克和土耳其的东南部、埃及东北部。研究小组负责人、美国加州大学洛杉矶分校的进化生物学家罗伯特·韦恩表示,家猫和很多其它的家畜也都起源于此,农业也是最先从这里发展起来的。
狗的起源一直是进化生物学上的热点问题。科学家认为它们是由灰狼驯化而来的,但对于起源地在哪里却各执一词。研究人员对来自于北美、欧洲、东亚和中东的900只狗(代表85个品种)以及200多只野生灰狼的基因进行了比较,得出了上述结论。
这是迄今为止对狗和灰狼进行的涵盖范围最广的遗传分析,科学家们使用了分子遗传技术,分析了所有实验动物的DNA中的4.8万多个遗传标记。他们发现,绝大多数狗都同来自于中东的灰狼(与其他地方的灰狼相比)共享了很多独特的遗传标记。他们也发现,狗同欧洲灰狼之间也有亲属关系,但是,关系并不密切。另外,有少部分东亚狗和中国灰狼之间也有遗传关系。
研究人员表示,第一只中东狗可能出现在1.2万年前到1.3万年前之间。第一个将野狼驯化成狗的人可能是游牧民族的猎人。在几千年的发展中,狗与人住得越来越近,并开始为人类提供保护,甚至帮助人们狩猎,最终成为人类的密友。
新的研究反驳了之前认为的所有的狗都源于东亚和中国的狼的结论。此前的研究基于对来自实验动物线粒体的单个小DNA序列的比较,而非对整个基因组的分子标记进行比较。韦恩认为,此次研究涵盖的狗和灰狼的品种更多,分析也更为全面。(生物谷Bioon.com)
更多阅读
高烧的GWAS——生物谷盘点2009
MBE:狗的祖先是中国驯狼
PNAS:建立全球幼犬祖先基因图 揭示家狗的起源
生物谷推荐原文出处:
Nature doi:10.1038/nature08837
Genome-wide SNP and haplotype analyses reveal a rich history underlying dog domestication
Bridgett M. vonHoldt1, John P. Pollinger1, Kirk E. Lohmueller2, Eunjung Han3, Heidi G. Parker4, Pascale Quignon4, Jeremiah D. Degenhardt2, Adam R. Boyko2, Dent A. Earl5, Adam Auton2, Andy Reynolds2, Kasia Bryc2, Abra Brisbin2, James C. Knowles1, Dana S. Mosher4, Tyrone C. Spady4, Abdel Elkahloun4, Eli Geffen6, Malgorzata Pilot7, Wlodzimierz Jedrzejewski8, Claudia Greco9, Ettore Randi9, Danika Bannasch10, Alan Wilton11, Jeremy Shearman11, Marco Musiani12, Michelle Cargill13, Paul G. Jones14, Zuwei Qian15, Wei Huang15, Zhao-Li Ding16, Ya-ping Zhang17, Carlos D. Bustamante2, Elaine A. Ostrander4, John Novembre1,18 & Robert K. Wayne1
Advances in genome technology have facilitated a new understanding of the historical and genetic processes crucial to rapid phenotypic evolution under domestication1, 2. To understand the process of dog diversification better, we conducted an extensive genome-wide survey of more than 48,000 single nucleotide polymorphisms in dogs and their wild progenitor, the grey wolf. Here we show that dog breeds share a higher proportion of multi-locus haplotypes unique to grey wolves from the Middle East, indicating that they are a dominant source of genetic diversity for dogs rather than wolves from east Asia, as suggested by mitochondrial DNA sequence data3. Furthermore, we find a surprising correspondence between genetic and phenotypic/functional breed groupings but there are exceptions that suggest phenotypic diversification depended in part on the repeated crossing of individuals with novel phenotypes. Our results show that Middle Eastern wolves were a critical source of genome diversity, although interbreeding with local wolf populations clearly occurred elsewhere in the early history of specific lineages. More recently, the evolution of modern dog breeds seems to have been an iterative process that drew on a limited genetic toolkit to create remarkable phenotypic diversity.