Physiology, Development and Neuroscience Dept, Cambridge University, Downing St, Cambridge, United Kingdom.
Placenta. 2010 Aug;31(8):675-85. doi: 10.1016/j.placenta.2010.04.001. Epub 2010 Jun 16.
Most lizards lay eggs. However viviparity has evolved in the Squamata on many separate occasions by the process of extended retention of the egg coincident with gradual loss of the eggshell. This process is linked to reduction of the amount of yolk which is coupled with development of placental nutrient transfer. The family Scincidae currently show a range of multiple independent origins of viviparity and placentation along this pathway, and the genus Mabuya shows one of the most structurally complex placentas. This study investigates the transport potential of the different areas of the Mabuya placenta using immunocytochemistry to localize the systems in place for calcium, glucose and water transfer. The localization of these transporters demonstrated restricted distributions in the specialized areas of this morphologically complex placenta.
大多数蜥蜴产卵。然而,通过延长卵的保留时间,同时逐渐失去蛋壳,有鳞目动物在许多不同的场合进化出了胎生方式。这个过程与卵黄量的减少有关,同时伴随着胎盘营养物质转移的发展。石龙子科目前在这条途径上显示出多种独立起源的胎生和胎盘形成,而麻蜥属则表现出最具结构复杂性的胎盘之一。本研究使用免疫细胞化学技术研究麻蜥胎盘不同区域的运输潜力,以确定钙、葡萄糖和水转移的系统位置。这些转运蛋白的定位显示在形态复杂的胎盘的特定区域有局限性分布。