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

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 (P0.01) 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.