Morphological and molecular characteristics of malaria vector anopheles superpictus populations in Iran

Background: Anopheles superpictus is one of the main malaria vectors in Iran. The mosquitoes of this species are found throughout the Iranian plateau up to 2000 meters above sea level in the Alborz Mountains, south of the Zagros Mountains, and in the plains near the Caspian Sea and Persian Gulf. It has been reported that different geographical populations of An. superpictus play different roles in malaria transmission. Based on the presence or absence of a black spot/band on the apical segment of the female maxillary palpi, two morphological forms have been reported in this species. This work has been conducted to study other morphological features as well as the genetic structure of these two forms of An. superpictus in Iran. Methods: The different morphological characteristics of 35 different populations were observed and recorded. An 887 bp portion of the mitochondrial DNA (mtDNA) cytochrome oxidase subunit I (COI) was amplified and assayed by restriction fragment length polymorphism (RFLP) using 18 enzymes and PCR-direct sequencing techniques.Results: Among the morphological characteristics studied, there are significant differences between the two forms with regard to the length of the palp light band (p<0.01), wing length (p<0.5), and the distance from the branching point of the II/IV veins to the tip of the wing (p<0.05). Results also revealed that these two forms are sympatric in most localities of Iran. RFLP analysis and sequences of about 710 bp of the gene showed that there was great variation between and/or within the populations, but these variations were not associated with the morphological forms.Conclusion: This is the first comprehensive study on the morphological and molecular characteristics of An. superpictus in the literature. To determine the role of these morphological forms or genetic haplotypes in malaria transmission, further molecular, cytological, morphological, and epidemiological studies are necessary.