Expanding southwest pacific mitochondrial haplogroups P and Q
Expanding southwest pacific mitochondrial haplogroups P and Q
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DOI：
10.1093/molbev/msi142
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发表时间：
2005-06-01
影响因子：
10.7
通讯作者：
Merriwether, DA
中科院分区：
文献类型：
--
作者：
Friedlaender, J;Schurr, T;Merriwether, DA
现代人类已经在新几内亚和附近的俾斯麦群岛和美拉尼西亚岛的所罗门群岛生活了至少4万年。先前的线粒体DNA （mtDNA）研究表明，该区域的两个共同谱系，单倍群P和Q，特别多样化，其中P的合并被认为比Q的合并要早得多。在本研究中，我们扩展了单倍群Q的定义，使其包括三个主要分支，每个分支由多个突变区分分开（Q1，相当于先前定义的Q1加Q2和Q3）。我们报告了三个完整的mtdna基因组，将Q2确定为主要的Q分支。此外，我们还描述了314个控制区序列，这些控制区序列属于西南太平洋收集的扩展单倍群P和Q。最大的P和Q分支（P1和Q1）的合并日期彼此相似（大约5万年），比先前的估计要早得多。新发现的Q2，是在美拉尼西亚岛东部的样本中发现的，稍微年轻了1万多年。我们的合并估计应该比以前的更可靠，因为它们是基于更大的样本以及完整的mtdna编码区测序。我们的估计大致与目前建议的新几内亚-萨胡尔第一次定居的日期一致。P和Q的系统地理学表明，古代新几内亚岛美拉尼西亚与澳大利亚几乎完全（女性）隔离，这可能从第一次定居开始就存在了。虽然Q随后在新几内亚-美拉尼西亚岛广泛多样化，但在澳大利亚尚未发现。迄今为止在澳大利亚和新几内亚发现的唯一共享的mtDNA单倍群仍然是非洲古猿的一个小分支。
Modem humans have occupied New Guinea and the nearby Bismarck and Solomon archipelagos of Island Melanesia for at least 40,000 years. Previous mitochondrial DNA (mtDNA) studies indicated that two common lineages in this region, haplogroups P and Q, were particularly diverse, with the coalescence for P considered significantly older than that for Q.In this study, we expand the definition of haplogroup Q so that it includes three major branches, each separated by multiple mutational distinctions (Q1, equivalent to the earlier definition of Q1 plus Q2 and Q3). We report three whole-mtDNA genomes that establish Q2 as a major Q branch. In addition, we describe 314 control region sequences that belong to the expanded haplogroups P and Q from our Southwest Pacific collection. The coalescence dates for the largest P and Q branches (P1 and Q1) are similar to each other (approximately 50,000 years old) and considerably older than prior estimates. Newly identified Q2, which was found in Island Melanesian samples just to the east, is somewhat younger by more than 10,000 years. Our coalescence estimates should be more reliable than prior ones because they were based on significantly larger samples as well as complete mtDNA-coding region sequencing. Our estimates are roughly in accord with the current suggested dates for the first settlement of New Guinea-Sahul.The phylogeography of P and Q indicates almost total (female) isolation of ancient New Guinea-Island Melanesia from Australia that may have existed from the time of the first settlement. While Q subsequently diversified extensively in New Guinea-Island Melanesia, it has not been found in Australia. The only shared mtDNA haplogroup between Australia and New Guinea identified to date remains one minor branch of P.