Le Polymorphisme des Chromosomes PolytÈNes deLathriopyga LongisetaCaroli (Collembole Neanuridae)

Abstract

SUMMARYThe polytene chromosomes of Lathriopyga longiseta from several European populations have been studied. The species has 2n = 12 chromosomes except for the specimens from the Greek population which show 2n = 14 chromosomes even though they have the typical morphological characters of L. longiseta. The comparison of the several caryotypes evidenced a strong polymorphism of the shorter chromosomes (IV-VI) so that it is hardly possible to homologize them in the different populations.The chromosome variability is due to different centromeric organisation as well as to the band sequence rather than to the different α-heterochromatin content.Chromosome polymorphism might be the consequence of the strategy of the species in the adaptation of its genotype to the different environments.