Improved breeding for disease resistant strain of fugu following whole genome sequencing

红鳍东方鲀（Takifugu rubripes）是目前已知的唯一一种经济鱼类。本研究的目的是建立利用基因组序列改良该物种抗病品系的策略.通过同源性搜索，我们成功地找到了许多与免疫反应相关的基因，如B细胞和T细胞相关因子，细胞因子，趋化因子，补体因子和凝集素。我们现在能够进一步研究针对寄生虫的免疫反应，因为这种鱼的体型很大，使我们能够分析与免疫相关的蛋白质和细胞。遗传连锁图：由于河豚基因组数据库中的序列高度片段化，因此需要制作一张遗传连锁图，以便于该物种的遗传研究。构建了包含1219个微卫星位点的连锁图谱，为86%的基因组组合提供了锚点.对寄生虫冈本异槽绦虫（Heterobothrium okamotoi）的抗性/敏感性的QTL分析。对河豚养殖来说最大的问题之一是寄生虫冈本异槽绦虫（Heterobothrium okamoti），它通过在鳃部吸血而引起贫血。该连锁图的建立使我们能够对与抗病性相关的分子进行QTL分析，尽管该物种的菌株相当有限。采用种间杂交技术，以草东方鲀（Kusa-fugu）、赤眼鳟（T. niphobles，这是抵抗寄生虫。F2代表现出广泛的个体差异的抗/感寄生虫。通过QTL分析，找到了寄生虫数量和寄生虫生长的两个QTL位点。进一步广泛的研究将导致基因的确定。

The fugu Takifugu rubripes is the only economic species among the fishes with genomes that have been sequenced. The aim of this study was to establish the strategy for the improved breeding for disease resistant strain of this species utilizing genome sequences.1. Search for immune factorsUsing homology searches, we succeeded to find many genes which are related to the immune reaction, such as B-cell and T-cell related factors, cytokines, chemokines, complement factors, and lectins. We are now able to make further investigations of immune response against the parasite, since this fish has a large body size that enables us to analyze proteins as well as cells related to immunity.2. Genetic linkage map.Since the fugu genome database is composed of highly fragmented sequences, we needed to make a genetic linkage map for the genetic research of this species. We have constructed the linkage map containing 1219microsatellite loci that provide anchor points to the 86% of the genome assembly.3. QTL analyses for resistance/susceptibility against a parasite, Heterobothrium okamotoi.One of the biggest problems for fugu culture is a parasite Heterobothrium okamoti, which cause anaemia by taking blood at the gill. Establishment of the linkage map enabled us to conduct QTL analysis of molecules related to disease resistance, although strains of this species are quite limited. We used inter species hybrid with Kusa-fugu, T. niphobles, which is resistant against the parasite. F2 generation showed wide individual variations in the resistance/susceptibility against the parasite. By QTL analysis, we found each two loci of parasite number and parasite growth. Further extensive research will lead to determination of the genes.