Sex chromosome and autosome divergence in Podisma (Orthoptera) in western Europe

Abstract

The chromosome complement of 2 chromosome races of the montane grasshopper Podisma pedestris from the Alps (XO and Neo-XY) and the Pyrenees (XO), together with the endemic Iberian related subspecies Podisma ignatii cantabricae and Podisma ignatii carpetana, have been analyzed by means of silver staining and specific fluorochromes. Nucleolar organizer regions activity and the nature and localization of heterochromatin show large differences between populations of P pedestris from the Alps and the Pyrenees. Differences are not found to the same extent between populations of P ignatii and P pedestris from the Alps. Some aspects of the evolutionary colonization of Podisma in meridional Europe are considered.