Targeting of Painting of fourth to roX1 and roX2 proximal sites links dosage compensation to heterochromatin in Drosophila melanogaster

• In Drosophila melanogaster, two chromosome‐specific targeting and regulatory systems have been described. The male‐specific lethal (MSL) complex supports dosage compensation by stimulating gene expression from the male X‐chromosome and the protein Painting of fourth (POF) specifically targets and stimulates expression from the heterochromatic 4th chromosome. The targeting sites of both systems are well characterized, but the principles underlying the targeting mechanisms have remained elusive. Here we present an original observation, namely that POF specifically targets two loci on the X‐chromosome, PoX1 and PoX2 (POF‐on‐X). PoX1 and PoX2 are located close to the roX1 and roX2 genes, which encode ncRNAs important for the correct targeting and spreading of the MSL‐complex. We also found that the targeting of POF to PoX1 and PoX2 is largely dependent on roX expression and identified a high‐affinity target region which ectopically recruits POF. The results presented support a model linking the MSL‐complex to POF and dosage compensation to regulation of heterochromatin.

Subject headings

NATURVETENSKAP  -- Biologi -- Genetik (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Genetics (hsv//eng)

Keyword

Genome-wide gene regulation

MSL

POF

Drosophila

heterochromatin

genetik

Genetics

Publication and Content Type

vet (subject category)

ovr (subject category)