PostDoctoral Research Fellowship in Polar Regions

这是一个博士后奖学金。研究人员将使用分子工具研究南极鱼类无法忍受水温超过6摄氏度的原因。这些鱼是极端恒温动物，在零度以下的水域中进化了500万到1500万年。目前尚不清楚这些鱼无法忍受温度升高是否反映在无法改变基因表达以应对热应激。拟议的实验将创建第一个cDNA（互补DNA）微阵列，从水蚤bernachii，一个常见的物种在麦克默多湾。经过不同时间适应4℃的鱼类组织将被用来构建一个复杂的多组织cDNA文库，其中包含在热暴露期间表达的基因。这个文库将用于制造一个cDNA微阵列，使我们能够监测数千个基因的同时表达。来自对照和热休克个体的RNA将用于创建荧光标记的cDNA探针，并与微阵列杂交，从而生成热反应基因的基因表达谱。主要的假设是，在T. bernachii和两个相关的南极物种中，不存在响应温度升高而改变基因表达的能力。来自南极物种的基因表达模式将与来自新西兰的温带近亲进行比较。这个项目将增加我们对与寒冷适应、低温性和极地动物对环境变化的响应相关的基因组机制的理解。

This award is for a postdoctoral fellowship. The investigator will use molecular tools study the reasons why antarctic fish are unable to tolerate water warmer than about 6oC. These fish are extreme stenotherms, having evolved in sub-zero degree waters for somewhere between 5-15 million years. It is not known at this time whether the inability of these fish to tolerate increases in temperature is reflected in an inability to shift gene expression in response to heat stress. The proposed experiments will create the first cDNA (complementary DNA) microarray from Trematomus bernacchii, a common species in McMurdo Sound. The tissues of fish acclimatized over varying time periods to 4oC will be used to construct a complex, multi-tissue cDNA library of genes expressed during heat exposure. This library will be used to fabricate a cDNA microarray that will allow us to monitor the simultaneous expression of thousands of genes. RNA from control and heat shocked individuals will be used to create fluorescently tagged cDNA probes to be hybridized to the microarray, thereby generating gene expression profiles for thermally responsive genes. The primary hypothesis is that the ability to shift gene expression in response to elevated temperature will be absent in T. bernacchii and two related Antarctic species. The gene expression patterns from the Antarctic species will be compared to their temperate relatives from New Zealand. This project will increase our understanding of the genomic mechanisms related to cold-adaptation, stenothermality, and the response of polar fauna to environmental change.