小鼠18号染色体肿瘤易感性QTL初步定位研究

目的:研究小鼠骨髓瘤SP2/0细胞肿瘤接种实验,BALB/c为易感性近交系小鼠,C57BL/6J为抗性近交系小鼠,亲本杂交产生F1和F2代小鼠,并在F2代小鼠中进行移植瘤实验。方法:选定2个分布于小鼠基因组的微卫星DNA为遗传标记,用PCR方法扫描了208只产生了移植瘤和未产生移植瘤的小鼠18号染色体基因组。结果:通过连锁不平衡制图(mapping)软件Map Manager QTX20分析,发现分布于18号染色体上2个高连锁值的QTL,其中一个QTL位于D18Mit123与D18Mit49之间,似然比(likelihood ratio statistics,LRS)达到25.1,变异解释率为26%;另一个QTL位于D18Mit68与D18Mit123之间,似然比达9.0,变异解释率为9%,这两个QTL的P值均<0.01。结论:QTL的发现对我们精确定位肿瘤易感性和抗性基因有极大的帮助。

Identification of Tumor Susceptible QTLs on Chromosome 18 in Mice

Experiments found that BALB/c was an inbred strain mouse of tumor susceptibility, whereas C57BL/6J mice were barely susceptible. For identification of tumor susceptible QTLs on chromosome 18 in mice, a genomic scan on chromosome 18 by using microsatellite markers and composite interval mapping analysis was conducted in 208 F2 mice. Two microsatellite DNA were selected as genetic markers for screening genomic DNA by using PCR, and computer software Map Manager QTX20 was used for linkages analysis. Results of mapping showed that two QTLs were found on chromosome 18. One QTL was located between D18Mit123 and D18Mit49, likelihood ratio statistics (LRS) reached 25.1 and percent of the total variance explanation (variation %) was 26%. Another QTL was located between D18Mit68 and D18Mit123, LRS was 9.0 and variation % was 9%. P<0.01 both. These results provide a basis for cloning tumor susceptible/resistant gene.