By means of mRNA differential display and cDNA library screening we have characterized a novel gene of the rat that is differentially expressed during spermatogenesis. Northern blot analyses showed that its mRNA reaches the highest level during the first meiotic prophase. The transcript appears to be testis-specific as it was not detectable in any of the nine other tissues tested. The full length ORF encodes a putative phosphoprotein containing a serine stretch and a bipartite nuclear localization signal, which we call Srsp1 ("serin-rich spermatogenic protein 1"). Comparison of the cDNA from SRSP1 with genomic sequences in databases allowed us to determine the number of introns; some putative regulatory sequences are proposed. This is the first report of a gene differentially expressed during spermatogenesis that codes for a protein containing a serine stretch.
Copyright 2002 S. Karger AG, Basel