ENU诱变银鲫F_1的遗传差异分析

Genetic diversity of F_1 individuals of ENU-mutated gibel carp,Carassius autatus gibeblio Bloch

本研究采用乙酰基亚硝基脲(ENU)浸泡的方法诱变银鲫(Carassius autatus gibeblio Bloch)持续2周,后经清水反复漂洗,再进行人工催产得到诱变银鲫同源自交F1,利用AFLP技术对诱变银鲫F1(30尾)和对照银鲫(25尾)进行DNA指纹图谱分析,发现了Ⅰ型(缺失型)特异位点和Ⅱ型(插入型)特异位点;同时对6尾诱变银鲫F1和2尾对照银鲫mtDNA进行全序列测序分析,发现诱变组突变位点几乎覆盖整个线粒体DNA,主要集中在13个蛋白质编码基因、12SrRNA基因、16SrRNA基因和D-Loop控制区;通过对诱变组(55尾)和对照组(17尾)mtDNA的NADH1与NADH2部分序列比对发现,诱变银鲫F1诱变率约为38%。以上实验结果表明,诱变银鲫F1核质遗传物质同时发生变异,且变异位点基本相同,银鲫雄性子代的突变率大于雌性子代。这为探索提高ENU诱导银鲫突变的效率和开发养殖鱼类新的育种技术提供了新的理论依据。

Gibel carps（Carassius autatus gibeblio Bloch）were exposed in ENU（1-ethyl-l-nitrosourea）solution （92.8mg/L）for about two weeks,then restored in fresh water for at least another two weeks.Then single mating was conducted to produce F1 siblings.From AFLP fingerprint,Ⅰ typ（edeletion）specific site and Ⅱ type（insertion） specific site were detected from genomic DNA（gDNA）of 55 F1 individuals,among which 30 were from mutation group and 25 were from control group.The whole mitochondrial DNA（mtDNA）sequences were compared between six F1 individuals（3♀,3♂）from mutation group and two（1♀,1♂）from its counterpart.Compared with control group,the mutative loci could be found in the entire mtDNA in mutation group which mainly located in 13 protein- encoding genes,12S rRNA gene,16S rRNA gene and D-loop control regions.The frequencies of ENU mutation could be up to 38%in calculating nucleotide changes of NADH1 and NADH2 sequences alone.The mutated F1 individuals have similar mutative locations and loci based on the results of AFLP and mtDNA sequence alignment,with the mutated F1 males seeming to have obtained more mutative loci than F1 females.This study offers direct data for estimation of ENU efficiency in gibel carps,and provides a new trial for fish breeding.