RESUMO
Aim To investigate the role of autophagy core protein Atg5 in maintaining epididymal physiological functions and sperm maturation. Methods The Atg5 conditional knockout mouse model of principle cells in the 4 - 5 segments of the epididymal caput was constructed by Cre/LoxP system. The mice were divided into three groups according to genotype: Atg5v(, Atg5u~ and Atg5~/~ . The pregnancy rate and litter sizes were recorded by mating experiments at the age of 8 weeks-old. Sperm motility, sperm counts were evaluated with computer-aided sperm analysis ( CASA) after 14 weeks of feeding. HE staining was conducted to observe the morphology of the epididymal caput. Western blot and immunofluorescence technologies were applied to verify the expression level of Atg5 and the impediment of autophagy after Atg5 conditional knock out. Results After tissue specific knockout of Atg5 in the 4-5 epididymal principle cells, the autophagy marker proteins, LC3- I and p62, were accumulated and autophagy was successfully blocked. There was no significant difference in the morphology of epididymal tissues of the three genotypes of mice, nor any statistically significant difference in sperm motility, sperm count, litter size and pregnancy rate. Conclusions Under normal conditions without external challenge, Atg5 conditional knockout led to autophagy blocking of epididymal caput, but had no effect on mouse epididymal function and sperm maturation process.