title: [Karyotype of the midge Chironomus heterodentatus Konstantinov from the group Obtusidens (Diptera, Chironomidae)].
abstract: 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.
authors.affiliation: Medical University, Saratov Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, Novosibirsk.
authors.forename: S I
authors.initials: SI
authors.lastname: Belianina
authors.forename: I I
authors.initials: II
authors.lastname: Kiknadze
authors.forename: N V
authors.initials: NV
authors.lastname: Polukonova
authors.forename: A G
authors.initials: AG
authors.lastname: Istomina
authors.forename: M T
authors.initials: MT
authors.lastname: Siirin
mesh_terms: D000818:Animals; D002683:Chironomidae / Q000235:genetics*; D002875:Chromosomes / Q000648:ultrastructure*; D007621:Karyotyping