约氏疟原虫卵囊与唾液腺子孢子不同时相点的CSP与MAEBL基因表达研究

Gene expression of circumsporozoite protein and erythrocyte binding protein of Plasmodium yoelii in the sporozoites from oocyst and salivary gland at different phases

目的为研究约氏疟原虫在蚊体内发育过程中,卵囊子孢子与唾液腺子孢子不同时相点的环子孢子蛋白(circumsporozoiteprotein,CSP)与红细胞结合蛋白(erythrocytebindingprotein,MAEBL)基因表达水平的变化。方法分别在约氏疟原虫感染斯氏按蚊后5、7、10d取蚊腹部、12、15、18d取蚊头胸部分离疟原虫总RNA,以rRNA28S为对照,通过RTPCR法半定量分析CSP与MAEBLmRNA表达量。结果蚊期疟原虫子孢子CSP与MAEBL转录显著上调(P<0.01),在侵入唾液腺后达到峰值。结论疟原虫唾液腺子孢子CSP和MAEBLmRNA高水平表达,提示CSP和MAEBL可能与侵入脊椎动物宿主密切相关。

Objective To study the gene expression change of circumsporozoite protein （CSP） and erythrocyte binding protein （MAEBL） in the Plasmodium yoelii sporozoites from oocyst and salivary gland at different phases during Plasmodium yoelii development in mosquitos. Methods The total RNA of plasmodium was extracted from the abdomen on day 5, 7, 10 and the thoraces on day 12, 15, 18 after Anopheles stephensi was infected by Plasmodium yoelii, then the expression of CSP and MAEBL mRNA was analyzed by semiquantitative RT-PCR with rRNA 28S as control. Results The transcription of CSP and MAEBL of plasmodium sporozoite were obviously up-regulated during the mosquito stage （P 〈 0. 01 ） and reached the peak after invading the salivary gland. Conclusion The high expression level of plasmodium sporozoite CSP and MAEBL in salivary gland suggests CSP and MAEBL may play a role in plasmodium invading the vertebrate host.