小鼠模型中疟原虫P.yoelii17XL易感位点的染色体定位  

Mapping for susceptibility gene to Plasmodium yoelii infection

作　　者：张娅琳 韩雪[1] 张一彤 杨冀 曹洪滔 祁赞梅 

机构地区：[1]中国医科大学基础医学院免疫学教研室,沈阳110122 [2]湖北省宜昌市疾病预防控制中心

出　　处：《公共卫生与预防医学》2017年第6期11-15,共5页Journal of Public Health and Preventive Medicine

基　　金："影响小鼠疟疾易感性的遗传机制研究"辽宁省高等学校科学研究一般项目(L2014304)

摘　　要：目的利用全基因组扫描方法,对BALB/c和DBA2小鼠基因组中疟原虫P.yoelii17XL(P.y17XL)易感位点进行染色体定位。方法以雌性BALB/c小鼠与雄性DBA2小鼠杂交建立杂交一代小鼠(C.DF1),以雄性C.DF1小鼠与雌性BALB/c小鼠回交,得到回交小鼠(C.DN2)。提取129只雌性C.DN2小鼠基因组DNA。利用扩增片段长度多态性确定每只小鼠分布于全基因组的微卫星遗传标记基因型;同时监测小鼠感染P.yoelii17XL后的原虫血症水平。采用基因定位专用软件(MAPMANAGER)进行数量性状位点(QTL)分析。结果 BALB/c小鼠感染P.y17XL后,原虫血症水平迅速攀升,于第6~7d全部死亡;DBA2小鼠感染后原虫血症水平上升缓慢,第10d的生存率为75.00%;C.DF1小鼠的原虫血症水平与DBA2相近,生存率为100.00%。对C.DN2小鼠基因组中的控制感染后原虫血症水平的QTL进行的连锁分析显示,控制感染后第3、4、5d原虫血症水平的QTL均与小鼠第3号染色体66.69c M处遗传标记D3Mit258连锁。此外,控制原虫血症水平的QTL还与第3号染色体的D3Mit307(19.01c M)、D3Mit278(32.59c M)、D3Mit75(43.73c M)以及第15号染色体的D15Mit90(30.86c M)形成有统计学意义的连锁。当C.DN2小鼠D3Mit278、D3Mit75、D3Mit258和D15Mit90位点为纯合的BALB/c来源的等位基因时,感染P.y17XL后的原虫血症水平低于以上位点基因型为杂合的小鼠;在D3Mit258基因型相同的小鼠中,D15Mit90位点为纯合的BALB/c来源的等位基因时,感染P.y17XL后的原虫血症水平低于以上位点基因型为杂合的小鼠。结论控制C.DN2小鼠感染P.y17XL后原虫血症水平的QTLs与遗传标记D3Mit307、D3Mit278、D3Mit75、D3Mit258、D15Mit90连锁。BALB/c小鼠来源的与D3Mit278、D3Mit75、D3Mit258和D15Mit90连锁的QTLs对P.y17XL的感染起抵抗作用。Objective To identify the Quantitative Trait Locus（QTL）for the genetic component of controlling malaria susceptibility in BALB/c. and DBA/2 mice. Methods Genome-wide linkage analysis was conducted. BALB/c. female mice were mated with DBA/ 2 males to produce the C. DF1 hybrid mice. C. DN2 backcross mice were obtained by crossing female BALB/c mice with male C. DF1 mice. Genome DNA was extracted from 129 female C. DN2 mice. Genome screening entailed genotyping of 129 female C. DN2 mice with59 microsatellite markers polymorphic between BALB/c mice and DBA/2 mice. Phenotypic values including survival rate andparasitemia were monitored. Linkage analysis was performed using the MAPMANAGER software. Statistical analysis was performed by using Student’s t test. P value of〈0. 05 was considered significant. Results After P. y17XL infection, all BALB/c mice died on the 6th and 7th day. The level of parasitemia and survival phenotype of C. DF1 mice were basically the same as their paternal DBA/2 mice,all of them survived. This analysis linked QTL controlling the level of parasitemia on the 3rd, 4th and 5th day to markers D3Mit258. In addition,the analysis of QTL controlling the level of parasitemia wdth D3Mit278（32. 59cM）, D3Mit75（43. 73cM）, D3Mit307（ 19. 01cM） and D15Mit90（30. 86cM））was statistically significant. On backcross mice,the C - type level of parasitemia was lower than the H - type group on markers： D3Mit258, D3Mit278, D3Mit75 and D15Mit90. When the backcross mice had the sa^ne genotype on D3Mit258, the C - type level of parasitemia was lower than the H - type group on D15Mit90. Conclusions The QTLs controlling the level of parasitemia in C. DN2 mice infected with P. y17XL linked to markers D3Mit258, D3Mit278, D3Mit307, D3Mit75 and D15Mit90. The QTLs derived from BALB/c linked to D3Mit258, D3Mit278, D3Mit75and D15Mit90 could resist the infection of P. y17XL.

关 键 词：约氏疟原虫 易感基因 染色体定位 BALB/C小鼠 DBA2小鼠 

分 类 号：R117[医药卫生—公共卫生与预防医学]