中文摘要：

目的观察不同种（株）利什曼原虫前鞭毛体和无鞭毛体的毒力相关基因表达情况。方法制备杜氏利什曼原虫、婴儿利什曼原虫、热带利什曼原虫、硕大利什曼原虫和墨西哥利什曼原虫等5种7株利什曼原虫前鞭毛体和无鞭毛体的总RNA,采用半定量RT-PCR法,以α-微管蛋白基因和3-磷酸甘油醛脱氢酶基因（GAPDH）作为阳性对照,根据GenBank公布的GDP甘露糖焦磷酸酶基因（GDPMP）、A2抗原相关蛋白基因（A2rel）、脂磷酸多糖合成蛋白1基因（LPG1）、脂磷酸多糖合成蛋白2基因（LPG2）、动基体膜蛋白11基因（KMP-11）、胱氨酸蛋白酶C基因（CPC）、亲水性酰化表面蛋白B1基因（HASPB1）、胱氨酸蛋白酶2基因（CPB2）、胱氨酸蛋白酶B2.8基因（CPB2.8）和热激蛋白100基因（CLPb）等毒力相关基因的核苷酸序列,设计特异性引物进行RT-PCR扩增,分析以上各基因在各种（株）前鞭毛体和无鞭毛体中的表达情况。结果各毒力基因在不同种（株）利什曼原虫的前鞭毛体和无鞭毛体中的表达明显不同,HASPB1基因在7个种（株）利什曼原虫的无鞭毛体和杜氏利什曼原虫前鞭毛体中均表达,GDPMP、LPG1、LPG2、CPB2.8、CPB2、A2rel和CLP基因分别在特定种（株）的前鞭毛体和/或无鞭毛体中表达,CPC基因仅在杜氏利什曼原虫SC10株和硕大利什曼原虫无鞭毛体内表达,KMP-11基因在7个种（株）利什曼原虫前鞭毛体或无鞭毛体内均不表达。结论毒力相关基因的表达存在种特异性和期特异性。

英文摘要：

Objective To investigate the expression level of virulence-associated genes in promastigotes and amastigotes of different Leishmania spp.. Methods Total RNA was extracted from the promastigotes and amastigotes of Leishmania donovani, L. infantum, L. tropica, L. major and L. mexicana, and relevant strains. According to the reported gene sequences in GenBank, primers were designed in relation to the virulence-associated genes [GDP-mannose pyrophosphorylase （GDPMP）, 3′a2rel-related protein （A2rel）, beta-galactofuranosyl transferase （LPG1）, lipophosphoglycan biosynthetic protein （LPG2）, kinetoplast membrane protein 11 （KMP-11）, cpc gene for cysteine proteinase （CPC）, hydrophilic acylated surface protein （HASPB1）, cathepsin L-like cysteine protease （CPB2）, cathepsin L-like cysteine proteinase lmcpb2.8 （CPB2.8）, Mr 100 000 heat shock protein （CLP b）], and control genes （alpha tubulin gene and GAPDH）. Semi-quantitative RT-PCR was performed to detect expression level of these genes in promastigotes and amastigotes of different Leishmania spp. Results There was a significant difference in the expression profiles of the genes among the promastigotes and amastigotes of different Leishmania spp. The HASPB1 was detected in the amastigotes of all strains and promastigotes of L. donovani, the GDPMP, LPG1, LPG2, CPB2.8, CPB2, CPC, A2rel and CLP b were expressed in the promastigotes and/or amastigotes of the specific Leishmania spp, respectively. None of the stains carried the KMP-11 gene, whereas the amastigotes of L. donovani SC10 strain and L. major 5ASKH strain possessed CPC. Conclusion The expression profile of the virulence-associated genes shows species-specific and stage-specific differences.