Genome instability ofChironomus ripariusMg. andChironomus pigerStrenzke (Diptera, Chironomidae)

Intra and interspecific variation was evaluated in two Bulgarian populations (Pancharevo and Koka- lijane) of the two sibling and homosequential species Chironomus riparius Mg. and Chironomus piger Strenzke, by analyzing structural and functional alterations in salivary gland polytene chromosomes. In both species genome in- stability was demonstrated, which was expressed by structural and functional somatic chromosomal alterations. In the C. riparius population from Pancharevo, living in sediments containing high concentrations of Cu, Pb and Zn, salivary gland cells containing somatic rearrangements appeared at a significantly higher frequency (51.92%) than in the Kokalijane C. piger popula…