INDUCTION OF C- AND G-TYPE BANDS ON IN VIVO METAPHASE CHROMOSOMES OF THREE SPECIES OF LARVIVOROUS FISHES
A.R. KHUDA BUKHSH *
DEPARTMENT OF ZOOLOGY, KALYANI UNIVERSITY, KALYANI-741235, INDIA.
S. DATTA *
DEPARTMENT OF ZOOLOGY, KALYANI UNIVERSITY, KALYANI-741235, INDIA.
*Author to whom correspondence should be addressed.
Abstract
Induction of C-or G-bands on in vivo metaphase chromosomes in fish is extremely difficult and needs a lot of variations in the pre-treatment schedule. In the present study, C- and G-type bands could be successfully induced in three species of larvivorous fishes, namely, Chanda nama (Fam : Centropomidae), Esomus dan rica and Puntius ticto (Fam : Cyprinidae) by deploying the BSG method with some minor modifications. While C nama showed localization of C-band heterochromatin mostly at or near the centromeric regions of the acrocentric chromosomes, E. danrica had mostly pericentric locations except for 2 to 3 pairs showings the entire chromosome length as C-band positive. On the other hand, P. ticto tended to show blocks of heterochromatin on the whole or one arm of several chromosome pairs (3 to 4 pairs), apart from a few pairs that either had centromeric or telocentric locations. Serial bands could be noted across the whole length of the metaphase chromosome of both C. nama and P. ticta, including several chromosomes showing Cbands as well. However, the G-type bands in E. danrica were not so well-defined, several pairs showing apparently lateral assymetry in band localization.