The evolutionary significance of placental interdigitation in mammalian reproduction: Contributions from comparative studies
The evolutionary significance of placental interdigitation in mammalian reproduction: Contributions from comparative studies
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DOI：
10.1016/j.placenta.2012.07.004
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发表时间：
2012-10-01
期刊：
影响因子：
3.8
通讯作者：
Capellini, I.
中科院分区：
文献类型：
--
作者：
Capellini, I.
胎盘是哺乳动物繁殖的基础，不同物种之间的大体形态差异令人惊讶。这种多样性是否以及如何影响母体投资和胎儿发育，目前仍知之甚少。与高侵入性血绒毛膜胎盘有利于胎儿发育的说法相反，最近的比较研究表明，交错--母体和胎儿组织在交换区域的接触程度--对胎儿生长速度有很大影响。具有迷宫胎盘的物种所产新生儿的大小与那些具有绒毛或小梁胎盘的物种相似，但所需时间不到一半。这些发现表明，胎儿生长率(较高的交错)和妊娠时间(较短的交错)之间可能存在权衡，与交错的类型有关。这种权衡可能是母子在母体资源分配上发生冲突的结果，父系基因倾向于更大的交错，因此胎儿生长更快，母系基因的反应是缩短怀孕时间。这些结果强调了交指作为一种增加交换表面积的手段的作用，并与物种内的研究一致，该研究表明，较高的交换表面积与较重的新生儿相关。进一步的研究可以调查其他特征在胎盘多样性进化中的作用及其对胎儿发育的影响。(C)2012爱思唯尔有限公司。保留所有权利。
The placenta is fundamental to mammalian reproduction and is surprisingly diverse in gross morphology among species. Whether and how this diversity affects maternal investment and fetal growth is still poorly understood. Contrary to suggestions that highly invasive hemochorial placentation is beneficial to fetal development, recent comparative studies have revealed that interdigitation - the degree of contact between maternal and fetal tissues at the area of exchange - strongly influences fetal growth rates. Species with labyrinthine placentae give birth to neonates of similar size to those of species with villous or trabecular placentae but in less than half the time. These findings suggest that there might be tradeoffs between fetal growth rates (higher with greater interdigitation) and gestation time (shorter with greater interdigitation), in association with type of interdigitation. Such tradeoffs might be the results of maternal-offspring conflict over the allocation of maternal resources, with paternal genes favouring greater interdigitation and so higher fetal growth, and maternal genes responding by reducing gestation time. These results emphasize the role of interdigitation as a means to increase the surface area for exchange, and are consistent with within species studies demonstrating that a higher surface area for exchange is associated with heavier neonates. Further studies could investigate the role of other traits in the evolution of placental diversity and their impact on fetal development. (C) 2012 Elsevier Ltd. All rights reserved.