Patterns of Second-to-Fourth Digit Length Ratios (2D:4D) in Two Species of Frogs and Two Species of Lizards at La Selva, Costa Rica
Patterns of Second-to-Fourth Digit Length Ratios (2D:4D) in Two Species of Frogs and Two Species of Lizards at La Selva, Costa Rica
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DOI：
10.1002/ar.22411
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发表时间：
2012-04-01
影响因子：
2
通讯作者：
Stynoski, Jennifer Lynn
中科院分区：
文献类型：
--
作者：
Direnzo, Graziella Vittoria;Stynoski, Jennifer Lynn
现在有充分的证据表明，雄激素和雌激素信号在早期发育过程中会导致第二到第四个指长比(2D：4D)的性别二型性。哺乳动物中雄性的2D：4D比雌性的要小，这一点也得到了很好的证明。尽管在鸟类身上的2D：4D研究之间存在差异，但一致认为鸟类表现出相反的模式，雄性比雌性具有更大的2D：4D。目前，文献缺乏关于两栖动物和爬行动物这一特征的系统发育模式的大量信息。在这项研究中，我们检测了两种蛙(Oophaga umilio和Craugastor bransfordii)和两种蜥蜴(Anolis humilis和Anolis limifrons)的2D：4D，以确定性别二型性的存在和模式。在两个前肢中，至少有一个雄虫的2D：4D比雌虫大。雄鼠双后肢2D：4D大于雌鼠，但前肢2D：4D小于雌鼠。在右前肢，雄蜂的2D：4D也可能比雌蜂小。最后，手指比例有时与体长呈正相关，表明异速生长。总体而言，我们的结果支持在两栖动物和蜥蜴中存在2D：4D性二型性，并增加了四足动物中2D：4D特征模式的知识。Anat Rec，295：597-603,2012。(C)2012年威利期刊公司。
It is now well documented that androgen and estrogen signaling during early development cause a sexual dimorphism in second-to-fourth digit length ratio (2D:4D). It is also well documented that males of mammalian species have a smaller 2D:4D than females. Although there are discrepancies among 2D:4D studies in birds, the consensus is that birds exhibit the opposite pattern with males having a larger 2D:4D than females. The literature currently lacks substantial information regarding the phylogenetic pattern of this trait in amphibians and reptiles. In this study, we examined 2D:4D in two species of frogs (Oophaga pumilio and Craugastor bransfordii) and two species of lizards (Anolis humilis and Anolis limifrons) to determine the existence and the pattern of the sexual dimorphism. Male O. pumilio and C. bransfordii displayed larger 2D:4D than females in at least one of their two forelimbs. Male A. humilis had larger 2D:4D than females in both hindlimbs, but smaller 2D:4D than females in both forelimbs. Male A. limifrons may also have smaller 2D:4D than females in the right forelimb. Finally, digit ratios were sometimes positively related to body length, suggesting allometric growth. Overall, our results support the existence of the 2D:4D sexual dimorphism in amphibians and lizards and add to the knowledge of 2D:4D trait patterning among tetrapods. Anat Rec, 295:597-603, 2012. (C) 2012 Wiley Periodicals, Inc.