EXAMINATION OF THE SAFETY OF INTRACYTOPLASMIC INJECTION PROCEDURES BYUSING BOVINE ZYGOTES

We have evaluated the safety of intracytoplasmic sperm injection (ICSI ) procedures by using bovine zygotes, Bovine zygotes were injected,vit h a small amount (2-3 pl) of either medium alone or medium containing polyvinylpyrrolidone (PVP) (sham-ICSI, without spermatozoon) using the same procedure as ICSI, and the subsequent in-vitro embryonic develop ment and embryo quality (number of cells/blastocyst) were examined. Co ntrol zygotes which had not been injected were similarly evaluated aft er in-vitro development, The sham-ICSI of either medium alone or mediu m containing PVP into bovine zygotes had no harmful effects on the rat e of normal fertilization and on the rate of development to hatched bl astocyst stage compared with those of controls (P > 0.05). In addition , no harmful effects were observed in the number of cells per blastocy st (embryo quality), The results suggest, for the first time, that the ICSI procedures currently used for animal and human ICSI are neither detrimental to embryonic development nor detrimental to embryo quality .