中国不同流行疫区利什曼原虫分离株的微卫星多态性分析  

Analysis on the Genetic Polymorphism of Microsatellite Markers in Leishmania donovani Isolates from Different Epidemic Foci

作　　者：张春莹[1] 宋兴勃[1] 严可宁[1] 代亚玲[1] 罗岚[1] 马莹[1] 

机构地区：[1]四川大学华西医院实验医学科,四川成都610041

出　　处：《现代预防医学》2014年第10期1852-1855,共4页Modern Preventive Medicine

摘　　要：目的了解中国荒漠、山丘和平原疫区利什曼原虫分离株的种群遗传学和流行病学特点。方法选用7个微卫星标记（Lm2TG，Li21—34，Li71—19，Li45—24，Li71—7，Li71—33，Li72—17／2）分别对中国不同疫区的5株杜氏利什曼原虫分离株（9044、SC9、771、LIU和XU）与WHO杜氏利什曼原虫参照株（MHOM／IN，80／DD8）进行PCR扩增和测序，分析序列的微卫星多态性，使用MEGA5．0软件构建系统发育树，推断杜氏利什曼原虫的种群结构。结果6株杜氏利什曼原虫分离株均扩增出7个微卫星位点。7个位点在杜氏利什曼原虫中检出3～7个等位基因，基因多样性最低为0＇5238（Li45—24），最高为1．000（Li72—17／2）。构建的系统发育树中，中国不同疫区的5株分离株与WHO参照株聚合为一群，其中山丘疫区四川犬分离株表现出明显的多态性。结论中国不同疫区杜氏利什曼原虫分离株的微卫星序列存在丰富的多态性，种系发育分析显示利什曼原虫遗传多态性与地理来源之间存在相关性。Objective This study was to address the population genetic and epidemiological characteristics in Chinese Leishmania donovani isolates from epidemic foci of desert, hill and plain. Methods A total of seven microsatellite DNA markers （Lm2TG, Li21-34, Li71-19, Li45-24, Li71-7, Li71-33, Li72-17i2） in L. donovani isolates were amplified by PCR and subsequently sequenced. The Neighbor-Joining （NJ） tree was constructed by MEGA 5.0 package to infer the population structure of the L. donovani isolates. Results The expected repetitive DNA fragments of 7 markers were amplified and sequenced in six isolates. Five were from epidemic foci in China （9044, SC9, 771, LIU, XU） and one was the WHO reference strain MHOMiINi80iDDS. Of the seven markers, 3 to 7 alleles were detected in the L. donovani isolates, with the minimal genetic diversity （GD） of 0.5238 （Li45-24） and maximal GD of 1.000 （Li72-17i2）. The constructed phylogenetic tree showed that the five isolates in China （9044, SC9, 771, LIU, XU） gathered together with L. donovani reference strain MHOMiINi80iDD8. Strain SC9 from canine in Sichuan Province showed rich genetic diversity. Conclusion The seven microsatellite DNA markers were rich in diversity in Chinese Leishmania strains which were isolated from different epidemic foci. Phylogenetic analysis displayed remarkable consistency between the pattern of genetic differentiation and geographic origins.

关 键 词：利什曼原虫 微卫星标记 种群遗传 

分 类 号：R382.22[医药卫生—医学寄生虫学]