Cellular Basis of Differential Limb Growth in Postnatal Gray Short-Tailed Opossums (Monodelphis domestica)
Cellular Basis of Differential Limb Growth in Postnatal Gray Short-Tailed Opossums (Monodelphis domestica)
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DOI：
10.1002/jez.b.22556
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发表时间：
2014-06-01
影响因子：
2.2
通讯作者：
Sears, Karen E.
中科院分区：
文献类型：
--
作者：
Beiriger, Anastasia;Sears, Karen E.
虽然对无脊椎动物的生长进行了广泛的研究，但对脊椎动物，特别是哺乳动物的生长控制机制仍然知之甚少。在这项研究中，我们调查的差异肢体生长在出生后的Monodelphis南极洲，灰色短尾负鼠的细胞基础，以深入了解调节哺乳动物生长的机制。负鼠是研究生长的理想模型，因为它们出生时具有相对较大，发育良好的前肢和较小的后肢，必须在动物成年前赶上前肢。出生后第1-17天被确定为后肢生长的关键时期，在此期间，它们经历加速发育，长度几乎是原来的四倍。对该时期的前肢和后肢进行的组织学检查表明，后肢长骨中的细胞分化率较高。免疫组织化学分析表明，细胞增殖也发生在一个显着更大的速度在后肢的长骨在出生后6天。总之，这些结果表明，相对于前肢，后肢长骨中细胞增殖和分化的速度更快，产生了一个加速生长的时期，通过该时期，M.南极洲已经实现。基因表达的测定表明，这种差异增长的分子基础不同于以前确定的差异出生前负鼠的前肢和后肢的增长。J. Exp. Zool.（Mol. Dev. Evol.）322 B：221-229，2014. (c)2014 Wiley Periodicals，Inc.
While growth has been studied extensively in invertebrates, the mechanisms by which it is controlled in vertebrates, particularly in mammals, remain poorly understood. In this study, we investigate the cellular basis of differential limb growth in postnatal Monodelphis domestica, the gray short-tailed opossum, to gain insights into the mechanisms regulating mammalian growth. Opossums are an ideal model for the study of growth because they are born with relatively large, well-developed forelimbs and small hind limbs that must catch up to the forelimb before the animal reaches adulthood. Postnatal Days 1-17 were identified as a key period of growth for the hind limbs, during which they undergo accelerated development and nearly quadruple in length. Histology performed on fore- and hind limbs from this period indicates a higher rate of cellular differentiation in the long bones of the hind limbs. Immunohistochemical assays indicate that cellular proliferation is also occurring at a significantly greater rate in the long bones of the hind limb at 6 days after birth. Taken together, these results suggest that a faster rate of cellular proliferation and differentiation in the long bones of the hind limb relative to those of the forelimb generates a period of accelerated growth through which the adult limb phenotype of M. domestica is achieved. Assays for gene expression suggest that the molecular basis of this differential growth differs from that previously identified for differential pre-natal growth in opossum fore- and hind limbs. J. Exp. Zool. (Mol. Dev. Evol.) 322B: 221-229, 2014. (c) 2014 Wiley Periodicals, Inc.