Fig 2: Expression and cellular localization of GAPDHS, PGK2 and LDHC in testes from young adults and elderly adults. (A-F) The testes of five samples from young adults and five from elderly men were (A) evaluated by Johnsen scoring method and analyzed by (B-E) western blotting and (F) immunohistochemistry; scale bar, 20 µm. The expression between young adult and elderly adult were compared statistically by Student's t-test; *P<0.05 and **P<0.01. ACTB, ß-actin; GAPDHS, glyceraldehyde-3-phosphate dehydrogenase, testis-specific; LDHC, lactate dehydrogenase C; PGK2, phosphoglycerate kinase 2.

Fig 3: Differential expression of GAPDHS, PGK2 and LDHC in human tissues and testicular germ cells. (A and B) Gene expression values from microarray data were re-analyzed from data sets (A) GDS3113 (human) and (B) GDS2390 (murine) from the Gene Expression Omnibus database by retrieving gene symbols in data analysis tools and plotted. GAPDHS, glyceraldehyde-3-phosphate dehydrogenase, testis-specific; LDHC, lactate dehydrogenase C; PGK2, phosphoglycerate kinase 2.

Fig 4: Immunofluorescence localization and intensity of GAPDHS, PGK2 and LDHC in ejaculated spermatozoa of normal, immature and asthenozoospermia samples. (A) Percentage of immature spermatozoa in normal and asthenozoospermia samples. (B) Percentage of progressive motility of spermatozoa from normal, immature and asthenozoospermia samples. (C) Representative images of PGK2 (green) expression localization in spermatozoa; scale bar, 5 µm; nuclei were stained with propidium iodide (red). (D and E) Quantitative analysis of (D) percentage of positive-stained cells and (E) fluorescence intensity of GAPDHS, PGK2 and LDHC on spermatozoa. Data were compared by one-way analysis of variance; *P<0.05 vs. N. AS, asthenozoospermia; GAPDHS, glyceraldehyde-3-phosphate dehydrogenase, testis-specific; IM, immature spermatozoa; LDHC, lactate dehydrogenase C; N, normozoospermia; PGK2, phosphoglycerate kinase 2.