Abstract: Rieske iron-sulfur protein (RISP) is one of key subunits in mitochondria complex Ⅲ that plays an important role in respiratory electron-transport chain. The full-length Spodoptera litura RISP cDNA (SlitRISP) of 4 413 bp was cloned and characterized by RT-PCR and RACE technique, which contains three introns. The open reading frame (ORF) of SlitRISP is 816 bp encoding 271 amino acid residues. The sequence analysis indicated that SlitRISP shares overall 83% and 79% amino acid sequence identity to the RISP sequences from Bombyx mori and Plutella xylostella， respectively. The qRT-PCR result revealed that the expression level of SlitRISP was significantly different in different stages of S. litura, which in larval and adult stages was significantly higher than that in egg and pupal stages, while the expression levels in 4th and 5th instars were clearly higher than that in the early instars and 6th instar. This study provides a foundation for understanding the SlitRISP function and its application as a new target for respiratory electron transport blocking agent in designing new and efficient insecticides.

Key words: Spodoptera litura, rieske iron-sulfur protein (RISP), gene structure, sequence analysis, expression profile