EPAS1介导藏獒骨髓低氧适应的造血调控机制

我们前期基因组结果发现低氧调控核心转录因子EPAS1是藏獒低氧选择信号最强基因，并具有降低血红蛋白浓度的遗传效应。前期血液生理结果发现，藏獒移居到平原血红蛋白浓度竟然未改变（典型遗传环境互作）？基于此，我们提出了遗传功能“突变”与环境调控“量变”的互作发生模式假设（巧适应？）。本研究拟通过易地饲养群体的骨髓表达谱检测，剖分遗传、环境、互作效应，探讨互作基因发生比例和互作效应大小？同时，拟通过骨髓红系造血祖细胞（BFU-E）常氧（21%）和低氧（1%）培养，从不同基因型的细胞生长表型剖析互作效应。最后，拟通过ChIP-seq、过表达、RNAi、荧光素酶报告基因和EMSA等技术检测EPAS1调控靶基因和结合元件，并设计两种基因型细胞的低氧和常氧培养，检测EPAS1“突变”与 “量变”的互作发生模式，揭示藏獒血液生理互作案例发生的分子机制。本研究是遗传环境互作适应分子机制研究的典型案例。

EPAS1, a core regulatory factor of hypoxia adaptation, is confirmed as the gene with the strongest selection signal in Tibetan mastiff and with the effects on decrease of RBC and blood resistance, however, the mechanism of hemopoietic regulation mediated by EPAS1 remains unclear. In addition, our previous results also revealed a typical case of interaction between gene and environment that there was not changes of hemoglobin concentration when Tibetan mastiff migrated to lowland. Based on the above, we proposed an interaction pattern exemplified by functional mutation and environment-regulated quantitative change. In this study, firstly, the local and migrated populations will be selected as materials to determine the hypoxic expression profile of hemopoietic system of bone marrow by transcriptome, and to dissect effects of gene, environment and their interaction. Secondly, the cell BFU-E will be selected to be cultured under normxia and hypoxia and to validated interaction by observe cell growth phylotype. Finally, on binding activity of transcriptional factors to regulatory element, such experiments as ChIP-seq, over-expression, RNAi, luciferase reporter gene and EMSA can be performed to determine the selectively binding of transcriptional factors to regulatory elements, and to explore the molecular mechanism of G×E interaction. This study can provide a typical case on research areas of G×E interaction respectively on the level of physiology, cell and molecular.