Mutations in the mod(mdg4) gene have effects on variegation (PEV), the properties of insulator sequences, correct path-finding of growing nerve cells, meiotic pairing of chromosomes, and apoptosis. The occurrence of FLYWCH motifs in mod(mdg4) gene product and other proteins is discussed in [1].

1: The modifier of mdg4 locus in Drosophila: functional complexity is resolved by trans splicing. Dorn R, Krauss V; Genetica 2003;117:165-177. PMID:12723696