[Functional organization of interbands in Drosophila polytene chromosomes].

The functional organization of particular chromosome regions is tightly associated with their function in eukaryotic cells. Details of this association are among the most topical problems of modem genetics. The paper characterizes the results of recent research of the specifics of the genetic organization and chromatin decondensation in interbands of Drosophila polytene chromosomes. Data on functional heterogeneity of interbands are considered. Experimental findings point to a lack of correlation between the decondensed chromatin state and the observed transcription level in particular interbands. The DNA sequences responsible for the interband formation are principally identifiable via site-specific homologous FRT/FLP recombination between two P transposons contained in chromosomes. The results allow a search for particular protein factors that are involved in the decondensed state of interbands and structural and functional differentiation of polytene chromosomes.