Genetic variability of diurnally sub-periodic Wuchereria bancrofti in Nicobarese tribe of Nicobar group of Islands, Andaman and Nicobar Islands, India.

Sub-periodic form of Wuchereria bancrofti occurs in several well-isolated islands of Nicobar group of islands of Andaman Nicobar archipelago, India, presenting an interesting situation to study the genetic variability of its population. Microfilariae collected from 40 microfilaria (mf) carriers residing in eight locations on five islands (five carriers from each locality) were studied for genetic variability by generating random-amplified polymorphic DNA profiles. Phylognetic analysis of the profiles revealed a considerable genetic variability among parasite populations of different islands. The Nei's gene diversity between populations of 40 individual mf carriers ranged from 0.0218 to 0.2400. It was highest (0.24) among the parasite populations of Car Nicobar island and lowest (0.0218) among those of Payuha area of Camorta island and Teressa island. The dendrogram constructed exhibited four distinct clusters, which are geographically localized, and the gene flow between them appears to be influenced by human migration pattern.