[Drosophila beta-heterochromatin: molecular organization and function. Cloning and molecular biological analysis of the lambda 20 DNA fragment from Drosophila melanogaster beta-heterochromatin].

To isolate the DNA sequences specific for the pericentric heterochromatin of Drosophila we used two CREST-autoimmune sera which bind in the Western-blot analysis the nuclear antigens of 30 kDa, 43 kDa and 45 kDa molecular weight. Cloning of the DNA fragments associated with these CREST-specific proteins of Drosophila resulted in obtaining 8 clones. One of them, lambda 20, hybridized mainly to the chromomcenter of polytene chromosomes. The further analysis indicated that the lambda 20 DNA might belong to the proximal beta-heterochromatin of the polytene chromosomes of D. melanogaster.