No abstract

Sperm-specific glyceraldehyde 3-phosphate dehydrogenase (GAPDS) originates from spermatogenic cells of the human testis. A strong staining of GAPDS was detected in epididymal epithelium, especially in principal cells and basal cells of the epithelium. GAPDS also bound to the fibrous sheet of the sperm tail and inhibited the motility and penetration ability of sperms. The rat model showed that at postnatal day 28 the spermatogenic cells began to express GAPDS protein. By day 60 its expression decreased in spermatogenic cells while it increased in Sertoli cells. After sexual maturation (120 days) GAPDS protein was expressed in both Sertoli cells and elongated sperms. The expression of GAPDS gradually increased with age in the epididymis.

THYmocyte differentiation antigen 1 (Thy-1), is a cell surface glycoprotein found on T cells and neurons and is involved in cell-to-cell interactions. In addition, Thy-1 knockouts (KO) are a potential mouse model of restless legs syndrome (RLS) based on clinical observations and the role of dopamine in the disease. In this study, we analyzed the activity and quantity of tyrosine hydroxylase (TH; the rate-limiting enzyme in dopamine production) and determined phosphorylation levels for the enzyme (phospho-serine-40 (pSer-40)). There was no significant difference in the total TH activity and pSer-40 TH levels between Thy-1 KO and control groups; however, TH specific activity was significantly lower (by 26%) in Thy-1 KO mice. This difference is, in part, due to increased TH protein levels in this group (increased by 29%). When analyzed by gender, we determined that Thy-1 KO female mice striata contained less TH specific activity compared to control females (decreased by 41%) and male control or Thy-1 KO animals (decreased by 30%). TH specific activity and pSer-40 TH levels between male Thy-1 KO and control displayed no differences. However, pSer-40 TH was significantly higher in control females (38%) compared to control or Thy-1 KO males. The Thy-1 KO females exhibited significantly lower (28%) pSer-40 TH (normalized to GAPDH or TH) than control females. Indeed, the Thy-1 KO females had 50% of the pSer-40 TH found in controls. Our results suggest a gender effect on TH specific activity, TH protein levels and serine-40 phosphorylation of TH in Thy-1 KO female mice.