“…As in the case of dsx, this regulation depends on binding a specific set of TRA/TRA-2 binding sites in the fru pre-mRNA (Heinrichs et al, 1998, Lam et al, 2003. Both TRA-2 226 and TRA-2 179 are expressed in the male germ line, but only the former is necessary and sufficient for male fertility, acting independently of TRA and affecting sex-specific processing of pre-mRNA from exuperantia (exu), alternative testis transcripts (att), and tra-2 itself (Hazelrigg and Tu, 1994, Madigan et al, 1996, McGuffin et al, 1998. TRA-2 226 represses the removal of the M1 intron of tra-2 pre-mRNA from mature mRNAs by binding to an intronic splicing silencer (tra-2-ISS), leading to the alternative TRA-2 179 non-functional isoform (Chandler et al, 2003, Mattox and Baker, 1991, Qi et al, 2007.…”