Loss-of-function alleles of the JIL-1 histone H3S10 kinase enhance position-effect variegation at pericentric sites in Drosophila heterochromatin

In this study we show that loss-of-function alleles of the JIL-1 histone H3S10 kinase act as enhancers of position-effect variegation at pericentric sites whereas the gain-of-function JIL-1^{Su(var)3-1[3]} allele acts as a suppressor strongly supporting a functional role for JIL-1 in maintaining euchromatic chromatin and counteracting heterochromatic spreading and gene silencing.