Comparative FISH analysis of distribution of B chromosome repetitive DNA in A and B chromosomes in two subspecies of Podisma sapporensis (Orthoptera, Acrididae)

FISH analysis of B chromosome repetitive DNA distribution in A and B chromosomes of two subspecies of Podisma sapporensis (P.s. sapporensis and P.s. krylonensis) was performed. In the B chromosomes, C-positive regions contained homologous DNA repeats present also in some C-positive A chromosome regions. Most C-negative regions contained DNA repeats characteristic of A chromosome euchromatic regions. The two subspecies analyzed differed in the location of A chromosome regions enriched with repeats homologous to repeats of B chromosomes. The only common region enriched with these B chromosome repeats in both subspecies was the X chromosome pericentromeric region. The origin of B chromosomes in P. sapporensis is discussed. Copyright (C) 2004 S. Karger AG, Basel.