Chironomus balatonicus Devai, Wülker & Scholl, 1983

Michailova, Paraskeva, 2024, Markers in the polytene chromosomes of freshwater Chironomus Meigen (Diptera, Chironomidae) species, Zootaxa 5453 (4), pp. 511-537 : 517

Chironomus balatonicus Devai, Wülker & Scholl

The species has 2n = 8. AB and CD chromosomes are metacentric, EF—submetacentric, G—telocentric. The centromere regions of all chromosomes are well identified ( Fig. 5 ). The band sequences in arm A are in an inverted state (A2.2). The smallest chromosome, G has three BRs and one NOR, one of the BR is not always expressed. The NOR and two BRs are situated at both ends of the chromosome. The chromosome has partial incomplete conjugation of the homologues. A chromosome marker is the two dark bands of chromosome G with several light ones in between ( Fig. 5 ). A high chromosomal polymorphism, appeared by homo- and heterozygous inversions, was found in the polytene chromosomes of the species from areas after Chernobyl nuclear power events, a highly radioactive area near Kyiv ( Petrova & Michailova 1996). An additional B chromosome is reported for the first time in a species from this region ( Michailova & Petrova, 1994). One hundred and forty-six individuals were studied.

Collected sites: Dimitrovgrad, Plovdiv: fish pool, Russe: Mechka, fish pool, Durankulak Lake .

Figures

FIGURE 5. Polytene chromosomes of Chironomus balatonicus. The numbers on the chromosome arms indicate the “basic”sequences.The large arrows show the localization of the centromere region. The small arrow on chromosome G indicates the marker sequences required for species identification. BR—Balbiani Ring, NOR—Nuclear Organizer Region. A, B, C, D, E, F, G—arms of the chromosomes. Scale bar, 10µm.