Rubenstein N M, Cunha G R, Wang Y Z, Campbell K L, Conley A J, Catania K C, Glickman S E, Place N J
Department of Psychology, University of California, Berkeley, CA 94720, USA.
Reproduction. 2003 Dec;126(6):713-9. doi: 10.1530/rep.0.1260713.
Female moles of the Old World genus Talpa display a curious suite of reproductive features that include a peniform clitoris and ovaries with a discrete interstitial gland or testis-like region (so-called 'ovotestes'). The masculinization of the female external genitalia in Talpa has accordingly been linked with secretion of androgens from the interstitial gland region of the fetal gonad. Although their ovarian morphology has received less attention, some species of New World moles also have ovaries with a pronounced interstitial gland (for example star-nosed mole, Condylura cristata), whereas females of other species do not (for example eastern mole, Scalopus aquaticus). Although it is difficult to determine the sex of both Old and New World moles, published accounts describing the external genitalia of female moles are available only for Talpa. The hypothesis that masculinization of the female external genitalia in moles is associated with the presence of an ovarian interstitial gland (OIG) was tested in the present study by using a comparative approach to determine whether these features are ever found in isolation of one another. Three genera of North American moles (Scapanus, Condylura and Neurotrichus) were studied and a peniform clitoris was found in all three species, but OIG were found in only two of three genera. The ovaries of S. latimanus and S. orarius were unremarkable, with no evidence of a discrete interstitial gland or testis-like region. Mapping these results onto recent talpid phylogenies indicates that loss of the bipolar ovarian morphology is a derived trait in Scapanus, and conclusively demonstrates that masculinization of the external genitalia in female moles can develop in the presence or absence of 'ovotestes'.
旧大陆鼹鼠属（Talpa）的雌性鼹鼠展现出一系列奇特的生殖特征，包括阴茎状阴蒂以及带有离散间质腺或睾丸样区域（即所谓的“卵睾”）的卵巢。因此，Talpa属雌性鼹鼠的外生殖器雄性化与胎儿性腺间质腺区域分泌雄激素有关。尽管它们的卵巢形态较少受到关注，但一些新大陆鼹鼠物种也有明显间质腺的卵巢（例如星鼻鼹，Condylura cristata），而其他物种的雌性则没有（例如东部鼹鼠，Scalopus aquaticus）。虽然很难确定新旧大陆鼹鼠的性别，但已发表的描述雌性鼹鼠外生殖器的文献仅涉及Talpa属。在本研究中，通过比较方法来检验鼹鼠雌性外生殖器雄性化与卵巢间质腺（OIG）存在相关这一假说，以确定这些特征是否彼此独立存在。对北美鼹鼠的三个属（Scapanus、Condylura和Neurotrichus）进行了研究，发现所有三个物种都有阴茎状阴蒂，但仅在三个属中的两个属中发现了OIG。将这些结果映射到最近的鼹鼠系统发育树上表明，双极卵巢形态的丧失是Scapanus属的一个衍生特征，并最终证明雌性鼹鼠外生殖器的雄性化在有或没有“卵睾”的情况下都可能发生。
