Pax3基因无义突变导致Wbct小鼠显性白斑形成  

Dominant Spotting Phenotype Resulted from a Nonsense Mutation of Pax3 in Wbct mouse

作　　者：徐向明[1,2] 王琳 翟国勤 龚文 华峥 陈兵 薛整风 

机构地区：[1]江苏畜牧兽医职业技术学院,江苏泰州225300 [2]扬州大学比较医学中心,江苏扬州225009

出　　处：《江苏农业学报》2008年第6期857-861,共5页Jiangsu Journal of Agricultural Sciences

基　　金：国家自然科学基金项目(30670299)

摘　　要：本研究将Wbct杂合子小鼠与背景品系小鼠C57BL/6(B6)配种,记录后代白斑小鼠与正常小鼠数目,采用卡方检验确定遗传模式。在突变基因初步定位基础上增加样品数及微卫星标记数目对突变基因进行精确定位,确定候选基因。采用PCR扩增后直接测序方法对候选基因Pax3进行序列分析。结果表明:Wbct突变呈单基因显性遗传,但在不同遗传背景中白斑表型存在差异;Wbct突变纯合子致死;Pax3基因编码区第88位密码子由UGC变为终止密码子UGA,导致蛋白编码提前终止,是引起白斑突变表型的原因。To study the heredity pattern and identify the mutation gene of a kind of white spot mouse （ named Wbct） obtained by ethylnitrosourea （ENU） mutagenesis, Wbct heterozygous mice were mated with normal C57BL/6 （B6） mice. Their offspring with normal or mutation phenotype were registered respectively and X^2 test was used to confirm the heredity pattern. Fine mapping was conducted by increasing [ （ B6×D2） ×B6 ] N2 mice DNA sample and microsatellite markers. Based on fine mapping, the candidate gene Pax3 was found. Pax3 gene from Wbct heterozygote was amplified by PCR followed by sequencing. Heredity test indicated that the white spot phenotype was controlled by a single dominant gene with 100% penetrance but was affected by genetic background. The homozygous mice could not survive. A C-to-A transversion at the 264th nucleotide in Wbct ORF introduced a pre-termination codon of amino acid and caused the phenotype of dominant white spot.

关 键 词：WBCT PAX3 基因 无义突变 白斑 小鼠 

分 类 号：Q754[生物学—分子生物学]