ITS 1 AND 2 BASED CHARACTERIZATION OF ALLOPATRIC POPULATIONS OF ARMIGERES (ARMIGERES) SUBALBATUS (DIPTERA: CULICIDAE) ASSOCIATED WITH FILARIAL TRANSMISSION

Armigeres subalbatus is known to be the vector for parasites of many human diseases like malaria, Japanese encephalitis, filariasis etc. In India, the molecular nature of Ar. subalabtus species is poorly understood. We studied ITS2 molecular characterization of two allopatric populations of this species. Methods: The ITS1 and 2 spacer regions of the two populations A and B of Ar. subalbatus were amplified and sequenced. Restriction digests were also generated using three restriction enzymes Hae III, PstI and Hpa II, however, only Hae III proved to be useful for distinguishing the two populations by ITS1, while none was found useful for ITS2 sequence. Results: The correlation of indel bias with intron length was also analyzed. Both ITS1 and 2 sequences showed positive correlation with intron length. The variation in intron length is mainly due to presence of highly repetitive sequences, which results in higher base pair length of introns. Both interspersed and tandem repeats were analyzed but none of the type of repeat was found to be common in both the sequences of populations A and B. In addition, secondary structures were also analyzed and only two portions were found to be similar in population A and B of both the sequences. Conclusion: An improved understanding of the mosquito population genetics is needed for insight into the population dynamics and dispersal, which can aid in understanding the epidemiology of disease transmission and control of the vector. From this comparative data, it is evident that detectable changes in the genome can prove useful as first indicators that a monotypic population actually consists of two or more genotypes.