Sequence and expression of testis-expressed gene 14 (Tex14): a gene encoding a protein kinase preferentially expressed during spermatogenesis

To discover germ cell-specific genes, we used in silico subtraction and identified testis expressed gene 14 (Tex14). Mouse Tex14 contains an open reading frame encoding a 1450-amino-acid protein, which shares 64% amino acid identity with the predicted human TEX14 protein. The predicted TEX14 amino acid sequence consists of three ankyrin repeats, a protein kinase domain, and a leucine zipper dimerization motif. Northern blot analysis and in situ hybridization show that Tex14 mRNA is expressed specifically in the testis, with highest levels observed in pachytene, diplotene, and meiotically dividing spermatocytes. Two 5' splice variants of mouse Tex14 were discovered by sequencing 5'-RACE polymerase chain reaction products. TEX14 is predicted to be localized to the nucleus, suggesting that it may play a key role in regulating gene expression or modulating nuclear events during mammalian spermatogenesis.     

Four isoforms of the signal-transduction and RNA-binding protein QKI expressed during chicken spermatogenesis

Genes expressed during spermatogenesis undergo alternative initiation and alternative splicing and may be under the control of a coordinated mechanism of RNA processing. A family of proteins that combine features of signal-transduction and RNA-binding molecules could be instrumental in this process. We have characterized a cDNA from adult chicken testis that codifies a highly conserved member of the STAR protein family, the orthologue of the mouse quakinggene qkI. The predicted chicken protein differs only in four amino acids from the corresponding mouse protein. Messages of 7, 6, and 5 kb are expressed differentially during chicken spermatogenesis. The 5-kb message, the predominant form in adult testis, presents heterogeneity in the coding region, showing insertions of 51 and 75 bp and a deletion of 24 bp, which gives rise to four possible isoforms of the protein. Mol. Reprod. Dev. 50:70–78, 1998. © 1998 Wiley-Liss, Inc.     

A mouse zinc finger gene which is transiently expressed during spermatogenesis

Zinc finger proteins are polypeptides with sequence-specific, nucleic acid-binding properties. Substantial evidence has established them as a class of trans-acting molecules with regulatory roles in cellular growth and differentiation. We have screened an 11.5 day post coitum urogenital ridge cDNA library with an oligonucleotide encoding a sequence conserved between a variety of zinc finger proteins. By cDNA cloning and sequencing we show that a novel mouse gene, Zfp-35, encodes a protein with a block of 18 zinc finger domains and an N-terminal region rich in acidic residues. The 2.4 kb mRNA encoding this polypeptide is selectively expressed in adult testis, by comparison with other organs. We have analysed Zfp-35 expression in whole testes of sex-reversed mice, whole testes of prepuberal XY animals, germ cell fractions from XY adult testes and by in situ hybridization to sections from adult XY testes. Our studies show that a considerable increase in expression is restricted to spermatocytes at the pachytene stage of meiotic prophase. These experiments suggest that Zfp-35 may act to control gene activity during this particular stage of spermatogenesis.     

Identification and characterization of TSAP, a novel gene specifically expressed in testis during spermatogenesis

Through in silico screens, we have identified many previously uncharacterized genes that display similar expression patterns as the mouse Dazl gene, a germ line-specific marker. Here, we report the identification and characterization of one of these novel genes. TSAP gene encodes a protein with 350 amino acids and contains five ankyrin repeats and a PEST sequence motif. Furthermore, we have generated an anti-TSAP antibody and have used three different approaches (RT-PCR, in situ hybridization, and immunohistochemistry) to investigate the expression profiles of TSAP mRNAs and proteins. TSAP is specifically expressed in testis, but not in other tissues such as ovary. Within the testis, TSAP is detected 10 days after birth and is mainly expressed in spermatocytes (ST) and later stage of germ cells, but not in spermatogonia (SG) or sertoli cells. Therefore, TSAP protein likely plays a role in spermatogenesis.