Associated component of the WMM complex, a complex that mediates N6-methyladenosine (m6A) methylation of mRNAs, a modification that plays a role in the efficiency of mRNA splicing and is required for sex determination. Required for sex determination and dosage compensation via Sxl alternative splicing: m6A methylation acts as a key regulator of Sxl pre-mRNA and promotes female-specific alternative splicing of Sxl, which determines female physiognomy. M6A methylation is also required for neuronal functions. Required for proper inclusion of regulated exons in Ubx transcripts, leading to isoforms Ia/b and IIa/b. Component of the WMM complex, a N6-methyltransferase complex composed of a catalytic subcomplex, named MAC, and of an associated subcomplex, named MACOM. The MAC subcomplex is composed of Ime4/Mettl3 and Mettl14. The MACOM subcomplex is composed of fl(2)d, Flacc/Xio, Hakai, vir, and, in some cases of nito. Interacts with vir and msk. Part of a complex containing fl(2)d, Sxl and vir. Belongs to the fl(2)d family.