EFFECT OF C-HETEROCHROMATIN IN CHIASMA TERMINALIZATION IN CHORTHIPPUS-BIGUTTULUS L (ACRIDIDAE, ORTHOPTERA)

Using the Giemsa C-banding procedure, a polymorphism in chromosome banding pattern has been found in a spanish population of Chorthippus biguttulus. The variation in C-banding pattern shown by bivalent M 6 allowed to study the effect of C-heterochromatin on chiasma terminalisation. The results indicate that interstitial heterochromatin acts as a barrier preventing chiasmata to pass. Anaphase separation seems to be normal but could be slightly delayed. A similar role for telomeric C-heterochromatin is suggested. © 1978 Springer-Verlag.