CRYOPRESERVATION OF MOUSE SPERMATOZOA FROM INBRED AND F1-HYBRID STRAINS

Mouse epididymal spermatozoa from inbred(BALB/c, C3H/He, C57BL/6N, CBA/JN and DBA/2N) and F1 hybrid (B6C3F1, BDF1 and CDF1) strains suspended in cryopreservation solution (18% raffinose and 3% skim milk in distilled water) were frozen and stored at -196-degrees-C . After thawing at room temperature, sperm motility and fertilizing ability were examined. Spermatozoa from all of the strains were successfully frozen, although the motility and the fertilization rates of frozen-thawed spermatozoa (the proportions of the fresh oocytes from Jcl : ICR strain which developed to pronuclear oocytes and 2-cell embryos after insemination by frozen-thawed spermatozoa) varied among strains (motility : 23% for C57BL/6N to 62% for DBA/2N ; fertilization rates : 26% for C57BL/6N to 89% for DBA/2N). Nearly all 2-cell embryos fertilized by frozen-thawed spermatozoa were transferred to the oviducts of pseudopregnant recepients and 35-62% of 2-cell embryos developed into normal young.