A bnk promoter drives expression of the Myd88 open reading frame. Myd88miRNA.bcd is located in an intron of Myd88bnk.int in opposite orientation.
In embryos carrying the P{Medea.myd88-int} construct, zygotic expression of Myd88bnk.int rescues the maternal effect embryonic lethality caused by Myd88miRNA.bcd.