The Reproductive Tissue Specific Cystatin Subgroup of Genes: Expression during Gonadal Development in Wildtype and Testatin Knockout Animals

Abstract

Testatin has been implicated in fetal testis development due to its restricted expression in pre-Sertoli cells immediately after the onset of Sry gene expression. However, testatin knockout mice showed normal testis development and fertility. We investigated the spatial and temporal expression pattern of the Cres/testatin subgroup of genes, including the novel gene Cstl1/Cres4, in fetal mouse gonads and in adult testis, epididymis and ovary. The genes are related to the family 2 cystatins of protease inhibitors. Using real-time PCR and in situ hybridization we could show that 4 subgroup genes, testatin, CstSC, CstTE-1/Cres3 and Cres are expressed in fetal testis. We also confirmed the expression of testatin, CstE2, CstSC, CstTE-1/Cres3, Cres, CstT and Cstl1/Cres4 in adult testis and CstE2, CstTE-1/Cres3, Cres and CstE1/Cres2 in adult epididymis. In testatin knockout animals, the expression of CstE2 was heavily downregulated in adult testis, but not in adult epididymis, compared to wildtype controls. In conclusion, an explanation for the lack of phenotype in testatin knockout mice could be functional redundancy with another member of the Cres/testatin subgroup. The most likely candidate/s would be CstSC, CstTE-1/Cres3 or Cres as they are expressed in the fetal testicular tubules in early testis differentiation together with testatin.

Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 3: Developmental changes in spermatid flagellum and cytoplasmic droplet and interaction of sperm with the zona pellucida and egg plasma membrane

“…Several new cystatin genes have been identified that differ from the classical family 2 cystatin genes. They are called the Cres/testatin subfamily and include eight mouse genes (Frygelius et al, 2007). The cystatinrelated epididymal spermatogenic protein called CRES [ID: T3-531] is a serine protease inhibitor for prohormone convertase 2 [ID: T3-532] Cornwall et al, 1992;Yuan et al, 2007).…”

Sex and the circuitry: progress toward a systems‐level understanding of vertebrate sex determination

“…In one particularly heroic experiment, the function of all three members of the insulin receptor tyrosine kinase family was eliminated before a sex‐reversed phenotype was observed 25. This and other studies52,53 expose the high level of genetic redundancy and transcriptional buffering present in the gonad transcription network at the time of sex determination, and predict that roles for many individual genes during sex determination will be masked. Yet over 50% of human disorders of sexual development (DSDs) remain unexplained by variation in known sex determination genes.…”

Evolution and human tissue expression of the Cres/Testatin subgroup genes, a reproductive tissue specific subgroup of the type 2 cystatins

“…Signal peptides were predicted by Ensembl and multiple sequence alignments were performed without signal peptides via ClustalW muscle alignment (http://www.ebi.ac.uk/clustalw). Common consensus sites were indicated according to previous publications Frygelius et al 2007).…”

“…Gallus gallus (chicken) ENSGALG00000008664 located in a region on mouse chromosome 2 Frygelius et al 2007). Their orthologs in human, rhesus, rat, mouse, and cow are in synteny (Fig.…”

“…An obvious explanation for the lack of testicular phenotype in these animals could be functional redundancy with other CTES genes. Three additional CTES genes, CstTE-1/Cres3, CstSC, and Cres, were further found to be expressed in the fetal testis in Sertoli and germ cells together with Testatin (Frygelius et al 2007).…”