Motility, morphology, mitochondria and ATP content of diploid spermatozoa from sex-reversed clonal diploid and neo-tetraploid loach, Misgurnus anguillicaudatus

Diploid spermatozoa were obtained from sex-reversed clonal diploid males and neo-tetraploid which derived from normal diploid x natural tetraploid cross followed by the 2nd polar body release inhibition. The spermatozoa from sex-reversed clonal diploid males exhibited a significant reduction in motility when compared with those from normal diploid and neo-tetraploid males. Electron microscopy revealed that diploid spermatozoa from sex-reversed clonal diploid and neo-tetraploid males exhibited normal shape similar to haploid spermatozoa from normal diploid males, except for larger sperm-head size and longer flagellum. Considering flow-cytometric results, volume of mitochondrial mass per spermatozoon was also increased in proportion to the elevation of ploidy status from haploid to diploid sperm. Diploid spermatozoa from neo-tetraploid increased the number of mitochondria and the ATP content, but those from sex-reversed clonal diploid males did not show such results.