Increased positive selection pressure within the complementarity determining regions of the T‐cell receptor β gene in New World monkeys
Increased positive selection pressure within the complementarity determining regions of the T‐cell receptor β gene in New World monkeys
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新世界猴 T 细胞受体 β 基因互补性决定中阳性区域选择压力增加
DOI：
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发表时间：
2011
影响因子：
2.4
通讯作者：
R. Suzuki
中科院分区：
文献类型：
--
作者：
T. Matsutani;Yoshiki Fujii;Kazutaka Kitaura;S. Suzuki;Y. Tsuruta;T. Takasaki;K. Ogasawara;N. Nishimoto;I. Kurane;R. Suzuki
由于TCR和MHC分子的长期共同进化，在TCRβ基因的结构域内积累了许多核苷酸取代。我们之前发现，非同义核苷酸取代发生在互补决定区（CDR）β比CDRα更频繁，即使只有有限数量的普通绒猴（Callithrix jacchus）和人类T细胞受体β可变区（TRBV）序列进行了比较。这一有趣的发现提出了一个问题，即CDRβ内增加的选择压力是否具有种属特异性。在这项研究中，我们从普通绒猴中鉴定了21个TRBV区域序列，并对人类、黑猩猩、恒河猴、棉顶绢毛猴、马氏夜猴和普通绒猴的T细胞受体α可变区（TRAV）和TRBV区域进行了比较序列分析。每个位点的非同义核苷酸取代数（dN）与dS值（dN/dS）的比值在TRAV和TRBV区域序列的框架区（FR）内小于1，表明纯化选择在FR内主要占主导地位。相比之下，在新世界猴中，CDRβ的dN值在统计学上显著大于CDRα。此外，在人类和新世界猴之间的CDRβ内观察到增加的dN/dS比率（dN/dS>1），有趣的是，在新世界猴之间，它们有一个相对较近的共同祖先。此外，通过最大似然分析进行的系统发育分析提供了有力的证据，支持沿着沿着新世界猴谱系在CDRβ内发生正选择。这些结果表明，CDRβ内增加的正选择压力在新世界猴中很常见，而不是种属特异性的。这项研究为灵长类动物体内TCR和MHC分子的共同进化提供了有趣的见解。Am. J. Primatol. 73：1082-1092，2011.© 2011 Wiley‐利斯公司
Because of the long‐term co‐evolution of TCR and MHC molecules, numerous nucleotide substitutions have accumulated within the domains of TCRβ genes. We previously found that nonsynonymous nucleotide substitutions occurred more frequently in complementarity determining region (CDR)β than in CDRα, even though only a limited number of common marmoset (Callithrix jacchus) and human T‐cell receptor β variable (TRBV) sequences were compared. This interesting finding raised the question of whether the increased selective pressure within CDRβ was species‐specific. In this study, we identified 21 TRBV region sequences from the common marmoset and performed comparative sequence analyses of the T‐cell receptor α variable (TRAV) and TRBV regions from human, chimpanzee, rhesus monkey, cotton‐top tamarin, Ma's night monkey, and common marmoset. The ratios of the number of nonsynonymous nucleotide substitutions per site (dN) to the dS values (dN/dS) were less than 1 within the framework regions (FRs) of TRAV and TRBV region sequences, suggesting that purifying selection is largely dominant within the FRs. In contrast, the dN values were statistically significantly greater for CDRβ than for CDRα only in New World monkeys. Also, increased dN/dS ratios (dN/dS>1) were observed within CDRβ between humans and New World monkeys and, interestingly, between New World monkeys, which share a relatively recent common ancestor. Moreover, phylogenetic analysis by maximum likelihood analysis provided firm evidence to support that positive selection occurred within CDRβ along New World monkey lineages. These results suggest that increased positive selection pressure within CDRβ is common in New World monkeys rather than being species‐specific. This study provides an intriguing insight into the co‐evolution of TCR and MHC molecules within primates. Am. J. Primatol. 73:1082–1092, 2011. © 2011 Wiley‐Liss, Inc.
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影响因子：
4.1
作者：
Opazo, Juan C.;Wildman, Derek E.;Goodman, Morris
通讯作者：
Goodman, Morris
影响因子：
32.4
作者：
Maynard, J;Petersson, K;Garcia, KC
通讯作者：
Garcia, KC
DOI：
10.1073/pnas.94.15.7799
发表时间：
1997-07-22
影响因子：
11.1
作者：
Nei, M;Gu, X;Sitnikova, T
通讯作者：
Sitnikova, T
影响因子：
3.7
作者：
Lanford, RE;Chavez, D;Brasky, KM
通讯作者：
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