confirmation of two sibling species among anopheles fluviatilis mosquitoes in south and southeastern iran by analysis of cytochrome oxidase i gene

b a ckground: anoph eles fluviatilis , one of the major malaria vectors in iran, is assumed to be a complex of sibling species. the aim of this study was to evaluate cytochrome oxidase i (coi) gene alongside 28s-d3 as a diagnostic tool for identification of an. fluviatilis sibling species in iran. m e t hods: dna sample belonging to 24 an. fluviatilis mosquitoes from different geographical areas in south and southeastern iran were used for amplification of coi gene followed by sequencing. the 474–475 bp coi sequences obtained in this study were aligned with 59 similar sequences of an. fluviatilis and a sequence of anopheles minimus , as out group, from genbank database . the distances between group and individual sequences were calculated and phylogenetic tree for obtained sequences was generated by using kimura two parameter (k2p) model of neighbor- joining method. results: phylogenetic analysis using coi gene grouped members of fars province (central iran) in two distinct clades separate from other iranian members representing hormozgan, kerman, and sistan va baluchestan provinces. the mean distance between iranian and indian individuals was 1.66%, whereas the value between fars province individuals and the group comprising individuals from other areas of iran was 2.06%. conclusion:   presence of 2.06% mean distance between individuals from fars province and those from other areas of iran is indicative of at least two sibling species in an. fluviatilis mosquitoes of iran. this finding confirms earlier results based on rapd-pcr and 28s-d3 analysis.