Fuels for development: evolution of maternal provisioning in asterinid sea stars
Fuels for development: evolution of maternal provisioning in asterinid sea stars
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发展的燃料：海星科海星母体供给的进化
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发表时间：
2008
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影响因子：
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通讯作者：
M. Byrne
中科院分区：
文献类型：
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作者：
T. Prowse;M. Sewell;M. Byrne
对于海洋无脊椎动物来说，幼虫的发育模式与卵的营养成分密不可分。在海星的asterinid家庭已经有多个，独立的，从祖先的lecithotrophic发展的进化过渡，lecithotrophic状态。要调查的孕产妇投资和发展的演化内的Asterinidae，我们量化的个人脂质类和总蛋白的鸡蛋和幼虫阶段的密切相关的物种代表三种发展模式（反式营养，反式lecithotrophy和底栖lecithotrophy）。在物种内，产妇提供不同的女性之间的鸡蛋质量随父母。母体投资与卵的大小有关，但在校正卵体积后，我们确定了与卵营养发育演变相关的两个主要的产卵修饰：（1）蛋白质沉积的减少，这可能反映了非摄食幼虫结构要求的减少，（2）一类能量脂质甘油三酯（TG）沉积的增加。例外的是甜菜小球藻，它具有底栖的、卵营养的发育，产卵的脂质与蛋白质的比例接近于嗜盐营养生物。这种产卵策略可能为甜菜夜蛾幼虫提供了一个蛋白质“重量带”，有助于维持底栖生存。海星类的营养型发展使用了一个显着的一部分鸡蛋TG建立一个喂养bipinnaria幼虫。Meridiastra mortenseni，女性特定的差异，在卵TG仍然是明显的bipinnaria阶段，表明鸡蛋质量有流动的影响，幼虫健身。在lecithotrophic asterinids，TG储备没有耗尽的发展到幼虫阶段，而蛋白质商店可能有助于燃料早期幼虫的发展。现有的数据表明，可能有两个进化稳定的自由产卵，温带棘皮动物的卵脂质配置文件。
For marine invertebrates, larval developmental mode is inseparably linked to the nutritional content of the egg. Within the asterinid family of sea stars there have been multiple, independent, evolutionary transitions to lecithotrophic development from the ancestral, planktotrophic state. To investigate the evolution of maternal investment and development within the Asterinidae, we quantified individual lipid classes and total protein for eggs and larval stages of closely related species representing three developmental modes (planktotrophy, planktonic lecithotrophy and benthic lecithotrophy). Within species, maternal provisioning differed between females indicating that egg quality varied with parentage. Maternal investment was related to egg size but, after correcting for egg volume, we identified two major oogenic modifications associated with the evolution of lecithotrophic development: (1) a reduction in protein deposition that probably reflects the reduced structural requirements of nonfeeding larvae, (2) an increase in deposition of a single class of energetic lipid, triglyceride (TG). The exception was Parvulastra exigua, which has benthic, lecithotrophic development and lays eggs with a lipid to protein ratio close to that of planktotrophs. This oogenic strategy may provide P. exigua larvae with a protein “weight-belt” that assists in maintaining a benthic existence. Asterinids with planktotrophic development used a significant portion of egg TG to build a feeding bipinnaria larva. For Meridiastra mortenseni, female-specific differences in egg TG were still evident at the bipinnaria stage indicating that egg quality has flow-on effects for larval fitness. In lecithotrophic asterinids, TG reserves were not depleted in development to the larval stage whereas protein stores may help fuel early larval development. Available data indicate that there may be two evolutionarily stable egg lipid profiles for free-spawning, temperate echinoderms.