Absence of mammary development in male Dromiciops gliroides: another link to the Australian marsupial fauna
Absence of mammary development in male Dromiciops gliroides: another link to the Australian marsupial fauna
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DOI：
10.1644/11-mamm-a-282.1
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发表时间：
2012-04-01
影响因子：
1.7
通讯作者：
Temple-Smith, Peter D.
中科院分区：
文献类型：
--
作者：
Frankham, Greta J.;Temple-Smith, Peter D.
南美洲微生物动物有袋类Dromiciops gliroides被认为是单系澳大利亚有袋类分支的姐妹分类群。乳房原基在美国雄性有袋类动物中有记载，但在任何澳大利亚有袋类动物中都没有观察到。本研究的目的是确定是否乳房原基存在于发育袋年轻（PY）的Dromiciops。对3只新生的雄性（n = 2）和雌性（n = 1）Dromiciops PY（与产后15-20天相似）的发育解剖学，特别是乳房原基的存在进行了研究。检查外部和内部结构，以确认PY性别，并提供发育的基本信息，特别是泌尿生殖系统。在雌性PY中观察到早期育儿袋发育以及4个明确定义的腹部乳房原基。在2只雄性PY中未观察到外乳头或乳房原基发育，从外生殖器到上胸部的连续切片未能显示与雌性中观察到的乳房原基相似的任何组织学结构。男性Dromiciops PY乳房原基的缺乏提供了进一步的证据，Dromiciops股更密切的关系，澳大利亚有袋动物分支比美国有袋动物区系。
The South American microbiotherian marsupial Dromiciops gliroides is regarded as a sister taxon to the monophyletic Australasian marsupial clade. Mammary anlagen have been documented in male American marsupials but have not been observed in males of any Australian marsupials. The aim of this study was to determine if mammary anlagen were present in developing pouch young (PY) of Dromiciops. The developmental anatomy, particularly the presence of mammary anlagen, was investigated in 3 neonatal male (n = 2) and female (n = 1) Dromiciops PY (similar to 15-20 days postpartum). External and internal structures were examined to confirm PY gender and to provide basic information on development, particularly of the genitourinary system. In the female PY early pouch development was observed as well as 4 clearly defined abdominal mammary anlagen. No external teat or mammary anlagen development was seen in the 2 male PY and serial sections from the external genitalia to upper thorax failed to reveal any histological structures similar to mammary anlagen seen in the female. Absence of mammary anlagen in male Dromiciops PY provides further evidence that Dromiciops shares a closer relationship with the Australasian marsupial clade than with the American marsupial fauna.