Marine Biotech Fellowship: Dietary Regulation of Gene Expression During Opportunistic Growth in a Polychaete

在温带生态系统中，大多数底栖生物群落在季节外观和机会主义成员的丰度方面表现出年之间的变化。这些生物的生活史策略似乎直接调节了它们的生长和繁殖。这可能是由于膳食微量营养素供应的年度差异造成的。机会主义的、以沉积物为食的多毛类面临着一种独特的营养限制：它们的小体型限制了它们可以储存的同化物质的数量。它们的生长和繁殖依赖于即时获得的饮食需求。虽然机会主义者的生长和繁殖受到食物供应的刺激，但人们对调节机会主义者生长多少和多快的饮食成分知之甚少。该项目将评估两种微量营养素（维生素D和类胡萝卜素b -胡萝卜素）在多食虫benedicti Streblospio基因转录水平上刺激体细胞分裂的潜力。C-myc原基因将用于在饲喂后立即（0-24小时）测定组织对饲粮成分的反应。定量c- myc mRNA转录水平将提供组织样本中细胞分裂活性的瞬时快照。将组织反应与快速生长和繁殖的生活史模式联系起来，将主要集中在评估维生素D或b -胡萝卜素启动和维持独立于饮食成分的有丝分裂循环的潜力。

In temperate ecosystems, most benthic communities exhibit between-year variability in the seasonal appearance and abundance of their opportunistic members. It seems likely that the life-history strategies of these organisms directly regulates their growth and reproduction. This may result form annual differences in the availability of dietary micronutrients. Opportunistic, deposit-feeding polychaetes face a unique nutritional constraint: their small body size limits the amount of assimilated materials they can store. They are dependent on the immediate availabilities of their dietary requirements to fuel their growth and reproduction. Although growth and reproduction in opportunists in stimulated by food supply, little is known about the dietary components that regulate how much and how fast an opportunist can grow. This project will assess the potential for two micronutrients (vitamin D and the carotenoid, B-Carotene) to stimulate somatic cell divisions at the gene transcription level in the polycheate worm, Streblospio benedicti. The C-myc protooncogne will be used to assay tissue responses to dietary composition immediately (0-24h) after feeding. Quantifying c- myc mRNA transcript levels will provide an instantaneous snapshot of cell division activity in a tissue sample. Relating tissue responses to a life-history pattern of rapid growth and reproduction will primarily focus on evaluating the potential for vitamin D or B-carotene to initiate and maintain mitotic cycling independent of dietary composition.