Faint gray bands in Drosophila melanogaster polytene chromosomes are formed by coding sequences of housekeeping genes

In this report, we test this idea using the X chromosome as the model and MSL1 as a protein marker of the lazurite chromatin. Our bioinformatic analysis indicates that in the X chromosome, it is only the lazurite chromatin that is simultaneously enriched for the proteins and histone marks associated with exons, transcription elongation, and dosage compensation. As a result of FISH and EM mapping of a dosage compensation complex subunit, MSL1, we for the first time provide direct evidence t hat lazurite chromatin forms faint gray bands. Our analysis proves that overall most of housekeeping genes typically span from the interbands (5′ region of the gene) to the gray band (gene body). More rarely, active lazurite chromatin and inactive malachite/ruby chromatin may be found within a com mon band, where both the housekeeping and the developmental genes reside together.

Source: Chromosoma - December 8, 2019 Category: Genetics & Stem Cells Source Type: research