Molecular phylogeny of RPB2 gene reveals multiple origin, geographic differentiation of H genome, and the relationship of the Y genome to other genomes in Elymus species
Molecular phylogeny of RPB2 gene reveals multiple origin, geographic differentiation of H genome, and the relationship of the Y genome to other genomes in Elymus species
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DOI：
10.1016/j.ympev.2007.12.024
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发表时间：
2008-03-01
影响因子：
4.1
通讯作者：
Daley, Tracy
中科院分区：
文献类型：
--
作者：
Sun, Genlou;Ni, Yan;Daley, Tracy
从同工酶和细胞学的研究推测，旧大陆和新世界类群可能是H基因组在th基因组物种中的独立起源。为了验证这一假设，并估计小麦科多倍体Elymus物种的系统发育关系，对36份含有StH或StY基因组的Elymus材料的RNA聚合酶II （RPB2）序列与Pseudoroegneria （St）、Hordeum (H)、Agropyron (P)、Australopyrum (W)、Lophopyrum （E-e）、Thinopyrum （E-b）和Dasypyrum (V)的序列进行了分析。我们的数据表明，羊草属物种的H基因组是根据地理来源分化的，欧亚和美洲的羊草属物种具有独立的异倍体起源，具有不同的H基因组供体。Y基因组序列与其他基因组供体（St、H、P、W）的系统发育分析表明，W和P基因组是Y基因组的姊妹基因组，具有87%的自引导支持度，而Y和H两个物种群的RPB2 St序列可能来自不同的Pseudoroegneria基因库。我们的数据不支持先前使用ITS数据的研究提出的St和Y基因组具有相同起源的建议。我们的研究结果对羊草Y基因组的起源及其与其他基因组的关系提供了一些见解。(c) 2008爱思唯尔公司版权所有。
It has been hypothesized from isozymic and cytological studies of Elymus species that the Old and New World taxa may be of separate origin of the H genome in the StH genome species. To test this hypothesis, and estimate the phylogenetic relationships of polyploid Elymus species within the Triticeae, the second largest subunit of RNA polymerase II (RPB2) sequence of 36 Elymus accessions containing StH or StY genomes was analyzed with those of Pseudoroegneria (St), Hordeum (H), Agropyron (P), Australopyrum (W), Lophopyrum (E-e), Thinopyrum (E-b) and Dasypyrum (V). Our data indicated that the H genome in Elymus species is differentiated in accordance with geographical origin, and that the Eurasian and American StH genome species have independent alloploid origins with different H-genome donors. Phylogenetic analysis of Y genome sequences with other genome donors (St, H, P, W) of Elymus revealed that W and P genomes are sister to Y genome with a 87% bootstrap support, and that StY and StH species group might have acquired their RPB2 St sequences from distinct Pseudoroegneria gene pools. Our data did not support the suggestion that the St and Y genomes have the same origin as put forward in a previous study using ITS data. Our result provides some insight on the origin of Y genome and its relationship to other genomes in Elymus. (c) 2008 Elsevier Inc. All rights reserved.