Inversion dynamics in some population of an emerging vector of malaria Anopheles (Celia) subpictus Grassi (Diptera: Culicidae)

The present paper deals with the polytene chromosome inversion polymorphism based genomic characterization of Anopheles subpictus Grassi (Culicidae: Diptera) which has attained the status of an emerging vector of malaria in Srilanka, West Bengal and some coastal parts of India. The inversion data of the present population from Hoshairpur, Punjab (pop.A), India has also been compared with five other populations of this species worked out earlier in this laboratory so as to have a comprehensive assessment of inversion dynamics in this taxon. From the percentage frequency of inversions it was also evident that both rural and urban populations of An. subpictus had nearly similar inversion frequencies. In addition to these observations, it was interesting to note that irrespective of the number of individuals sacrificed, cells studied and the number of aberrations encountered from each population, inversions always constituted 50% of the total mutational index. On the basis of the present comparative data of inversion polymorphism, it is logical to suggest that, similar to “meiotic drive” and “molecular drive” there is also a type of “inversion drive” which constantly changes population genomics to augment competitive fitness of the species. Our recent studies on the r DNA ITS2 sequence variations also suggest this contension.