Mouse sperm delivery via cauda epididymis without transport medium

This study was aimed to investigate the effects of room temperature (RT, 20-25 oC) and absence of medium during cauda epididymis transport on spermatozoa quality, fertility and embryo development. In the first experiment, fresh sperm from one side of cauda epididymis was used for in vitro fertilization, and another side was delivered at RT or 4-8 oC either with or without M2. In the second experiment, each side of cauda epididymis obtained from the same mouse was individually delivered at RT or 4 oC with or without M2. Finally, sperm motility, progressive motility scores and fertility of fresh spermatozoa or those from transported cauda epididymis, and IVF embryo development were evaluated. Progressive motility scores and fertilization rates were higher in fresh spermatozoa than transported sperm; sperm motility of transported cauda epididymis at 4-8 oC was comparable to fresh spermatozoa, but spermatozoa motility of transported cauda epididymis at RT was inferior to fresh spermatozoa. Spermatozoa motillty of transported cauda epididymis at 4-8 oC with transport medium was much higher than that without transport medium; absence of transport medium did not affect sperm motility of transported cauda epididymis at 4-8 oC but affected sperm motility of transported cauda epididymis at RT. Sperm quality from transported cauda epididymis can be efficiently kept at 4-8 oC, and cauda epididymis transport at 4-8 oC without M2 is more beneficial on keeping their fertility. Moreover cauda epididymis transport at RT without medium could sufficiently produce embryos for obtainning live offsprings.