Molecular characterization and expression analysis of teflon, a gene required for autosomal bivalent adhesion in meiosis I in males. J.E. Tomkiel , A. Briscoe Jr. Ctr Molec Medicine & Genetics, Wayne State Univ, Detroit, MI.

   In recombination-proficient organisms, paired homologues are held together at meiosis I by stabilization of chiasmata by sister chromatid cohesion proteins (cohesins). Male Drosophila, however, lack cross-overs and therefore must have evolved a different mechanism for maintaining bivalent integrity. We have shown that the teflon gene product is required for proper adhesion of autosomal bivalents at meiosis I in males. The sex bivalent is unaffected by tef mutations, indicating that there are genetically separable pathways for sex chromosome and autosome homologue adhesion. Here we describe a molecular characterization and expression analysis of the tef gene. Tef protein contains three putative zinc finger domains, one at the amino terminus and two in tandem at the carboxy terminus. Point mutations that disrupt the amino terminal zinc finger or truncate the carboxy terminal zinc finger behave as null alleles, implicating these domains in teflon function. In situ hybridization detects tef mRNA during preblastoderm embryonic stages, but not during later stages. Null alleles exhibit no maternal effect, indicating that tef function is nonessential or redundant during early development. RT-PCR expression analysis indicates that in adult males teflon message is specifically expressed in testis. The tef message is detectable by RT-PCR in can, mia, aly, sa and twine mutant testis, suggesting that it is expressed early in gonial cell development. Based on the similarity of tef zinc fingers to zinc fingers in known transcription factors, and the presence of tef message in transcriptionally quiescent embryonic stages, we propose that Tef protein may act as a negative regulator of transcription. We will report on a preliminary microarray analysis of tef vs. wildtype testis RNA aimed at testing this hypothesis and identifying downstream genes in the tef pathway.