eLife Assessment
This valuable study identifies asymmetric dimethylarginine (ADMA) modification of histones as a potential key determinant of the initial genomic binding of Rhino, a Drosophila-specific chromatin protein essential for piRNA cluster specification. The authors provide correlative genomic and imaging data to support their model, although functional validation of the proposed mechanism remains incomplete. Testing the redundancy between dART4 and dART1, which together could affect the prominent piRNA loci, in addition to the minor ones investigated in the manuscript, may change our assessment.