SNP标记对角膜混浊小鼠 突变相关基因的精细定位

为深入研究前期工作中以ENU诱变技术建立的遗传性角膜混浊突变系小鼠(B6-Co)的遗传机制, 利用 SNP标记对其突变基因进行精细定位, 将该品系中具有角膜混浊表型的小鼠(B6-CoP)与DBA/2小鼠(简称D2)配种得到F₁代, 再回交D2亲本品系得到F₂代, 提取F₂代角膜混浊小鼠鼠尾DNA。在MGI数据库中选取小鼠13号染色体已定位区间附近5个在C57BL/6(简称B6)和D2两个品系之间有差异的SNP, 应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)技术及连锁分析方法对B6-Co小鼠突变基因进行精细定位。结果表明: B6-Co小鼠突变基因定位于13号染色体上112 546 283~113 397 654 bp之间, 因该区间内有5个已知基因, 其中Map3k1基因与小鼠眼睛形态生成和眼睑闭合密切相关, 提示Map3k1是B6-Co小鼠突变的强力候选基因。

Fine mapping of mutant gene related corneal opacity mouse with SNPs

To further investigate the genetic mechanism of the mutant mice(B6-Co) with hereditary corneal opacity phenotype obtained by ENU-induced mutagenesis from B6 in previous study, SNP markers were used to map the mutant gene of B6-Co mice. F₂ generation mice were bred by backcrossing (B6-CoP×D2 )F₁ with D2 and the DNA samples of F₂ mutant mice were extracted from the tails. Five SNP sites that showed differences between B6 and D2 strains nearby the located region on chromosome 13 were screened from MGI database. Five SNPs, PCR-RFLP and linkage analyses were carried out to map the mutant gene. The result showed that the mutant gene was located between 112 546 283~113 397 654 bp on chromosome 13. There are five identified genes including Map3k1 that is associated with eye morphogenesis and eyelid closure of mouse in this region. This suggests that Map3k1 is the most probable candidate mutant gene of B6-Co mice.