CYTOLOGY OF POLYPEDILUM-NUBIFER (DIPTERA-CHIRONOMIDAE)

Abstract

Polypedilum nubifer has four polytene chromosomes (2n = 8). A standard chromosome map of the polytene chromosomes and the limits of 29 alternative sequences are described. Phylogenies for the sequences on arms C, E and G are proposed. Sequences C4, E3, FI and G1 are apparently quite ancient, and therefore probably ancestral, because of their occurrence in widely separated populations in Australia and Israel. There were no common sequences in arms A, B and D, but sequences Al, B1 and D1 are the most widespread in Australia. P. nubifer is female heterogametic, females always being heterozygous for a heterodhromatinized differential segment 41dY-dY on arm G. On the basis of the differing freque..