关键词: 杜氏利什曼原虫, ESAG样蛋白, 表达, 定位, 消减抑制杂交

Abstract:

Objective  To clone the novel gene that specifically expressed in the amastigotes of Leishmania donovani， and observe subcellular localization of the gene encoding protein.  Methods  mRNA from promastigotes and amastigotes of L. donovani were prepared. The novel expressed sequence tag of amastigotes was selected by suppression subtractive hybridization. The expression of the novel gene in different stages of L. donovani was detected by Northern hybridization and semi-quantitative RT-PCR. The subcellular localization of the novel gene encoding protein was observed.  Results  The subtractive library of the specifically expressed sequence tag of amastigotes was constructed， and a novel gene designated as expression site associated genes-like protein（ESAGLP） gene was cloned. The full length of ESAGLP cDNA was 2 258 bp. The open-reading frame encoded a polypeptide of 620 amino acid residues. ESAGLP gene expressed only in amastigotes， the encoding protein was localized in the mitochondria.  Conclusion  The ESAGLP gene is identified as a novel gene which specifically expressed in Leishmania donovani amastigotes， and its encoding protein is localized in the mitochondria.

Key words: Leishmania donovani, ESAG-like protein, Expression, Localization, Suppression subtractive hybridization