Metabolic Physiology During Embryonic and Larval Development of Antarctic Echinoderms

南极棘皮动物胚胎和幼虫发育过程中的代谢生理学

• 批准号: 9420803
• 负责人: Donal Manahan
• 金额: $ 39.97万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-06-15 至 2000-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9420803&HistoricalAwards=false
• 关键词: Metabolic; Physiology; During; Embryonic; Larval

Manahan 9420803 Feeding larval forms of benthic marine invertebrates in the cold waters of McMurdo Sound, Antarctica are present in the water column for many months prior to the phytoplankton bloom. It is currently not understood how these feeding larvae of antarctic invertebrates survive long periods under starvation conditions. Knowing the physiological mechanisms of this process is important for understanding the ecology of larvae from antarctic regions. Recent findings with antarctic echinoderm larvae do not support the suggestion that feeding larvae survive this period of negligible phytoplankton abundance by using other food sources (bacteria or dissolved organic material). Physiological data, however, do suggest a possible survival strategy whereby potential larval lifespans can be extended for about one year in the complete absence of food. Such lifespans (without food) for feeding larval forms are unique to antarctic larvae. The metabolism of this process in antarctic echinoderm larvae is the focus of this research. A hypothesis that the metabolic cost of development will be lower in antarctic echinoderms than for the same "unit of differentiation" (fertilized egg to feeding larval form) in comparable temperate larvae will be tested. Such data on temperate larvae already exist and the proposed studies with antarctic larvae will allow for a comparison of stage-specific developmental metabolism. To obtain these metabolic data, a novel technique called coulometric respirometry that permits continuous measurements of metabolic rate during development will be used. In addition, the biochemistry of development will be examined to determine the mechanism(s) of low metabolism in antarctic larvae. Data from experiments will test long-standing hypotheses about cellular mechanisms of low metabolism as they apply to invertebrate development in antarctic environments. The findings from this research may also have implications for larvae developing under lo w food conditions in other cold environments, such as the deep sea.

Manahan 9420803在南极洲麦克默多海峡寒冷的沃茨中，在浮游植物大量繁殖之前，底栖海洋无脊椎动物的幼虫形式在水柱中存在了许多个月。 目前还不清楚这些无脊椎动物的幼虫是如何在饥饿条件下长期生存的。 了解这一过程的生理机制对于了解南极地区幼虫的生态学具有重要意义。 最近的研究结果与无脊椎棘皮动物幼虫不支持的建议，喂养幼虫生存这一时期的浮游植物丰度可以忽略不计，通过使用其他食物来源（细菌或溶解的有机物质）。 然而，生理数据确实表明了一种可能的生存策略，即在完全没有食物的情况下，幼虫的寿命可以延长约一年。 这样的寿命（没有食物）喂养幼虫的形式是独特的无脊椎动物幼虫。 本研究的重点是这一过程在无脊椎棘皮动物幼虫体内的代谢。 一个假设，即代谢成本的发展将是较低的无脊椎棘皮动物比相同的“分化单位”（受精卵喂养幼虫的形式）在可比的温带幼虫进行测试。 这种数据温带幼虫已经存在，拟与南极洲幼虫的研究将允许特定阶段的发育代谢进行比较。 为了获得这些代谢数据，将使用一种称为库仑呼吸测定法的新技术，该技术允许在发育期间连续测量代谢率。 此外，还将对发育的生物化学进行检查，以确定无脊椎动物幼虫低代谢的机制。 实验数据将测试长期存在的假设低代谢的细胞机制，因为它们适用于无脊椎动物的发展在缺氧环境。 这项研究的发现也可能对在其他寒冷环境（如深海）中低食物条件下发育的幼虫产生影响。