Cloning, characterization, and expression analysis of goat (Capra hircus) phospholipid hydroperoxide glutathione peroxidase (PHGPx).

Phospholipid hydroperoxide glutathione peroxidase (PHGPx), as a ubiquitous antioxidant enzyme in the glutathione peroxidases (GPx) family, plays multiple roles in organisms. However, there is very little information on PHGPx in goats (Capra hircus). In this study, a full-length cDNA was cloned and characterized from Taihang black goat testes. The 844 bp cDNA contains an open reading frame (ORF) of 597 bp. The goat PHGPx nucleotide sequence contains a selenocysteine (sec) codon TGA(244-246), two potential start codons ATG(20-22) and ATG(108-110), a polyadenylation signal AATAAA(813-818) and selenocysteine insertion sequence (SECIS) motif AUGA(688-691), UGA(729-731) and AAA(703-705). As a selenoprotein, the active-site motifs and GPx family signature motifs LAFPCNQF(101-108) and WNFEK(165-170) were also found. The order of PHGPx mRNA expression levels was: testes >> heart > brain > epididymis > kidney > liver > lung > spleen > muscle. Real-time PCR and immunohistochemistry results revealed similar expression differences in different age testes, with high expression levels during adolescence. Immunofluorescence results suggested that PHGPx mainly expressed in Leydig cells and spermatids in mature goat testes.

Effect of elemental nano-selenium on semen quality, glutathione peroxidase activity, and testis ultrastructure in male Boer goats.

The objective of this experiment is to study the effects of novel elemental nano-selenium in the diet on testicular ultrastructure, semen quality and GSH-Px activity in male goats. Forty-two 2-month-old bucks were offered a total mixed ration which had been supplemented with nano-Se (0.3mg/kg Se) or unsupplemented (the control group only received 0.06mg/kg Se-background), for a period of 12 weeks (from weaning to sexual maturity). Results showed that the testicular Se level, semen glutathione peroxidase and ATPase activity increased significantly in the nano-Se supplementation group compared with control (P<0.05). The semen quality (volume, density, motility and pH) was not affected by added Se in diets, however, the sperm abnormality rate of control bucks was significantly higher than Se supplemented bucks (P<0.05). The testes of 5 goats in each group were examined by transmission electron microscopy (TEM), and showed that in Se-deficient bucks the membrane was damaged, and showed the occurrence of abnormalities in the mitochondria of the midpiece of spermatozoa. In conclusion, selenium deficiency resulted in abnormal spermatozoal mitochondria, and supplementation with nano-Se enhanced the testis Se content, testicular and semen GSH-Px activity, protected the membrane system integrity and the tight arrayment of the midpiece of the mitochondria. Further studies are required to research the novel elemental nano-Se with characterization of bioavailability and toxicity in small ruminants.