A PRELIMINARY SURVEY OF MITOCHONDRIAL SEQUENCE VARIATION IN TRIATOMINAE (HEMIPTERA, REDUVIIDAE) USING POLYMERASE CHAIN REACTION-BASED SINGLE-STRAND CONFORMATIONAL POLYMORPHISM (SSCP) ANALYSIS AND DIRECT SEQUENCING

Genetic variation within triatomine bugs was investigated by amplifica tion of a 400 bp portion of the mitochondrial 16S ribosomal RNA gene b y polymerase chain reaction (PCR), using evolutionarily conserved prim ers, from a selection of species representative of the genera Rhodnius , Triatoma and Panstrongylus. Amplification products were subsequently screened for sequence variation using single strand conformational po lymorphism analysis (SSCP) and also subjected to direct sequencing. Si ngle strand conformational polymorphism analysis could detect variatio n within and between genera; intraspecific variation was also detected and SSCP profiles appear to be useful for identification purposes at the inter- and intraspecific levels. A 290 bp multiple alignment of 15 sequences obtained from nine species was generated, phylogenetic infe rence subsequently used three methods; a distance estimate, maximum pa rsimony and maximum likelihood. This 16S region exhibited considerable variation which ranged from intergeneric to intraspecific levels. Phy logenies from these three methods of inference were in broad agreement . Triatoma and Panstrongylus were more closely related to each other t han either was to Rhodnius, in keeping with the current taxonomic appr aisal.