Karyotype of the midge Chironomus heterodentatus Konstantinov from the group Obtusidens (Diptera, Chironomidae)
Belianina, S.I.; Kiknadze, I.I.; Polukonova, N.V.; Istomina, A.G.; Siirin, M.T.
Tsitologiia 42(6): 593-601
2000
ISSN/ISBN: 0041-3771 PMID: 10953867 Document Number: 525442
The karyotype of Chironomus heterodentatus, belonging to the obtusidens-group described by Konstantinov from the Volga in 1956, was studied in detail. Combinations of chromosomal arms are AB, CD, EF and G (cytocomplex thummi). The Ch. heterodentatus karyotype cleary differs from those of other members of the obtusidens-group with a species-specific banding pattern in arms A, B, C and D. Chromosomal polymorphism on homo- and heterozygous inversions was found in arms, A, B, D, E and G. 19 inversion banding sequences and their 27 genotypic combinations have been recorded. The shortest arm G is highly polymorphic. Heterozygotes on the Balbiani ring activity were found in arm G along with homo- and heterozygotes on inversions. B-chromosomes with a frequency equal to 2.7-25.0% were recorded in some Volga populations.