罗非鱼低氧胁迫转录组响应及耐受性状QTL分析

水中溶氧含量不足或缺氧能导致严重的生态和水产养殖问题。应用分子标记辅助育种技术选育具有更强低溶氧耐受能力的鱼类新品种对于提高鱼类低氧逆境胁迫下的生存能力及增加养殖产量具有重要意义。鱼类低溶氧耐受性状属于复杂的经济性状，受到多基因调节。目前鱼类低溶氧耐受性状的遗传基础仍然不清楚。本项目在前期研究基础上，拟首先采用RNA-seq技术对罗非鱼不同器官低溶氧逆境胁迫下的基因时空响应模式进行分析，揭示罗非鱼低溶氧逆境胁迫响应过程中参与调节的功能基因及调控网络；进一步通过结合候选基因作图、数量性状座位（QTL）连锁作图和关联作图等方法，对影响罗非鱼低溶氧耐受性状的遗传网络进行解析，鉴定耐低氧性状相关的QTL及与性状紧密连锁的分子标记。本项目将阐明罗非鱼低溶氧耐受性状的遗传基础，为进一步开展分子标记辅助育种研究奠定基础。

Global warming causing from climate changes may be one of the biggest challenges to humankind today. Long-term trend of global warming will gradually increase the frequency of occurrence and severity of hypoxia in aquatic systems throughout the world. Recently,the rapid development and application of intensive fish culture system in aquaculture have introduced a strong requirement for fish lines with better hypoxia tolerance trait... The worsening hypoxic conditions could cause serious problems, e.g., direct mortality, reproduction, reduced growth rates and altered behaviour and distributions of aquatic animals, in aquatic ecosystem and aquaculture of commercially important species. The negative effects of hypoxia can be compromised by selection of new fish lines with stronger hypoxia tolerance using molecular marker-assisted selection technique. However,the genetic basis for hypoxia tolerance in fish remains unclear. .. Tilapia is the common name of a group of cichlid fishes native to Africa. Tilapia has become the third most important fish in aquaculture after carp and salmon, with a worldwide production of 3,500,000 metric tons in 2010. To date, no gene expression profiling and quantitative trait locus (QTL) mapping for hypoxia tolerance trait in Tilapia have been reported... Previously we have performed several genomic studies for Tilapia, e.g., in silico mapping of gene-associated SNPs, genome-wide scaning for signatures of recent selection, which provide valuable marker resources for QTL study. This proposed project aims to: (1) identify the genes, pathways and regulation networks involved in response to hypoxia stress in Tilapia by using RNA-seq technique; (2) explore the genetic basis of hypoxia tolerance in Tilapia using a combined strategy,e.g.,candidate gene mapping, QTL linkage mapping and association mapping.The results obtained from this project will deepen our understanding of the adaptations to hypoxia in fish. The availability of QTLs and markers that closely associated to hypoxia tolerance will facilitate the identification of candidate genes in fish by using a map-based cloning method, and will also be a valuable resource for genetic improvement of fish by using marker-assisted selection and/or gene selection methods.