Eukaryotic General Transcription Factors (GTF) are protein complexes that help position RNA polymerase at promoters and initiate transcription. The general transcription factors TFIIA and TFIID are multi-subunit protein complexes that physically associate with each other and assemble on promoters early in the process of transcription initiation. TFIIA consists of three protein subunits. In D. melanogaster, a single gene, tfiia-l, encodes a 48 kD polypeptide that is proteolytically cleaved to form two proteins of 30 kD and 20 kD. tfiia-s encodes the small subunit of 14 kD. Both the large and small subunits are widely expressed in many tissues and cell types. A homolog of the small subunit, tfiia-s-2 (CG11639), is expressed only in the male germ-line. We have shown that two transcripts are encoded by tfiia-s-2, and that both proteins are able to interact with the generally expressed large subunit when expressed in E. coli. Together, this suggests that three different forms of TFIIA might be present in the male germ-line. TFIID is comprised of TATA-binding protein (TBP) and up to fourteen TBP-associated factors (TAFs). Several testis-specific TAFs have been identified. Mutations in the testis-TAFs cause defects in transcription and block spermatid differentiation, however, there is no mutant allele of tfiia-s-2. We are investigating the possibility that the testis-specific TFIIA and TFIID homologs work together to during transcription initiation in the male germ-line. We are also characterizing the ability of complexes containing TFIIA-S-2 to physically associate with TFIID subunits and testis-expressed homologs of TFIID subunits.