UNCORRECTED PROOF
Polytene Chromosomes of an Indian Himalayan black fly Simulium (Nevermannia) praelargum (Diptera: Simuliidae)
Willie HENRY1, Subrata Kumar DEY2, Rakesh VARMA1, Sachin THAPA1, William S PROCUNIER3
1 2
P.G. Department of Zoology, Darjeeling Government College, Darjeeling, West Bengal 734101, India School of Biotechnology, West Bengal University of Technology,BF-142, Sector 1,Salt Lake City, Kolkata 700064, West Bengal, India
3
Consultant, North Bay, Ontario, P1B 5W6, Canada
Abstract High quality polytene chromosome maps (n=3) of a Himalayan Simuliid Simulium praelargum Datta, 1973 are presented and represent the first cytological description of a taxon found in the feuerborni group, subgenus Nevermannia. Polytene chromosomes one (I) and two (II) are metacentric, chromosome three (III) is submetacentric with the length of each chromosome occupying 37.25 %, 31.36 % and 31.34 % of the total complement length, respectively. Typical simuliid diagnostic intergeneric chromosomal markers are found within the polytene complement of this species. The nucleolar organizer (N.O.) is found at the base of the short arm of chromosome one (IS), the Ring of Balbiani (R.B.), double bubble (D.B.) and triad occur in the short arm of chromosome two (IIS), the Parabalbiani Ring (P.B.) and grey band (gb) occur in the long arm of chromosome two (IIL) and the Blister (B) and Capsule (Ca) occur in the short arm of chromosome three (IIIS).Terminal bands at the end of IIIS are heterochromatinized and present atypically with respect to other simuliid fauna. Populations studied so far are unique among the Simuliidae in that they exhibit chromosome structural monomorphism. These high resolution polytene chromosome maps will form the basis for future cytological characterization and phylogenetic comparisons amongst members of the feuerborni group [Current Zoology 56 (4): – 2010]. Key words