The Structure and Expression of the F6.2 Gene form Chironomus thummi and other Chironomus Species

Abstract

A full-length copy of the F6.2 gene from the tissue-specific BRa locus of the Chironomus thummi chromosome IV was isolated and analyzed. The gene contains two exons (715 and 644 bp, respectively) and one 172-bp intron. The data of the RT-PCR analysis demonstrated that F6.2 was transcriptionally active at different developmental stages of Chironomus thummi and at least in the last larval stage of C. dorsalis. The distribution of the F6.2 gene among 42 species of Chironomus, as well as among two other genera of the family Chironomidae was examined by means of PCR. The F6.2 sequence was found in 34 Chironomus species. Using in situ hybridization, three species were analyzed for the presence of the F6.2 homologous sequences. In five species, the sequence of the F6.2 PCR product was determined. In these species, the intron size polymorphism caused by the variation of the number of the intron-forming repeats was observed. The data obtained provided evaluation of the F6.2 distribution among the genus Chironomus.