Homology of Balbiani ring DNA in two closely related Chironomus species.
Cytogenetic analysis indicates that Balbiani Ring 2 (BR 2) in the two sibling species Chironomus tentans and Chironomus pallidivittatus arises from identifically banded segments in the salivary gland polytene chromosomes, although chromosomal rearrangements have occurred. In situ hybridization of BR 2 RNA to the polytene chromosomes of each individual species, as well as their F1 hybrids, reveals that the repetitious BR 2 DNA in the two species has, within the limits of the technique, retained identity of nucleotide sequences and degree of repetition. The DNA of the naturally expressed BR 1 and BR 3 in both species and that ot the galactose induced BR 6 in C. pallidivittatus did not hybridize with BR 2 RNA, indicating that these BR's are different from BR 2 with regard to sequence content.
D000818:Animals; D001345:Autoradiography; D002875:Chromosomes; D003562:Cytidine; D004247:DNA; D004175:Diptera; D005690:Galactose; D009693:Nucleic Acid Hybridization; D012313:RNA; D012469:Salivary Glands; D014316:Tritium; D014529:Uridine
D014316:Tritium; D003562:Cytidine; D012313:RNA; D004247:DNA; D014529:Uridine; D005690:Galactose