[Drosophila beta-heterochromatin: molecular organization and function. Characteristics of the DNA sequences from proximal beta-heterochromatin, associated with the nuclear envelope of Drosophila melanogaster].

To study the nucleotide sequence from the pericentric heterochromatin associated with the nuclear envelope, a residual DNA was extracted from the DNAse-treated nuclear lamins of Drosophila melanogaster tissue culture cell line Kc. The isolated DNA was cloned in lambda vector. The DNA library obtained was screened for the clones homologous to the pericentric heterochromatin. The experiments on in situ hybridization to the polytene chromosome of the nurse cell nuclei of the strain fs(2) B assigned the reiterated sequence, homologous to the lamin DNA clone, to the nuclear envelope associated regions of the proximal beta-heterochromatin which is known to undergo structural reorganization during cell differentiation. The nucleotide analysis of 300 bp from this sequence has established the presence of 21 bp and 300 bp d(GT/CA), 12 bp AT-box, the regions of recognition of the nuclear factor and the inverted repeats.