Soggy, a spermatocyte-specific gene, lies 3.8 kb upstream of and antipodal to TEAD-2, a transcription factor expressed at the beginning of mouse development

摘要

Investigation of the regulatory region of mTEAD-2, a gene expressed at the beginning of mouse preimplantation development, led to the surprising discovery of another gene only 3.8 kb upstream of mTEAD-2. Here we show that this new gene is a single copy, testis-specific gene called Soggy (mSgy) that produces a single, dominant mRNA -1.3 kb in length. It is transcribed in the direction opposite to mTEAD-2, thus placing the regulatory elements of these two genes in close proximity. mSgy contains three methionine codons that could potentially act as translation start sites, but most mSGY protein synthesis in vitro was initiated from the first Met codon to produce a full-length protein, suggesting that mSGY normally consists of 230 amino acids (26.7 kDa). Transcription began at a cluster of nucleotides approx150 bp upstream of the first Met codon using a TATA-less promoter contained within the first 0.9 kb upstream. The activity of this promoter was repressed by upstream sequences between -0.9 and -2.5 kb in cells hat did not express mSgy, but this repression was relieved in cells that did express mSgy. mSyg mRNA was detected in embryos only after day 15 and in adult tissues only in the developing spermatocytse of seminiferous tubules, suggesting that mSgy is a spermatocytespecific gene. Since mTEAD-2 and mSgy were not expressed in the same cells, the mSyglmTEAD-2 locus provides a unique paradigm for differential regulation of gene expression during mammalian development.