Porcine embryos produced after intracytoplasmic sperm injection using xenogeneic pig sperm from neonatal testis tissue grafted in mice

摘要

Embryo development after homologous intracytoplasmic sperm injection (ICSI) with sperm from testis tissuenxenografts from pigs or any other farm animal species has not been evaluated critically. Here, we report development ofnporcine embryos in vitro following ICSI with sperm retrieved from xenografted neonatal pig testis. Small pieces of testisntissue from newborn pigletswere grafted under the back skin of castrated immunodeficient mice (n=4) and the xenograftsnwere collected 8 months after grafting. Spermatozoa were recovered by mincing of the grafted tissue. For comparison,ntesticular, epididymal and ejaculated spermatozoawere also collected from mature boars. Oocytes injected with xenogeneicnspermatozoa were either fixed to determine fertilisation processes (n=89 in five replicates) or allowed to develop in vitron(n=143 in four replicates). Xenogeneic porcine spermatozoa were fertilisation competent (24% v. 58%, 68%, 62% or 0%nfor xenogeneic v. control testicular, epididymal and ejaculated spermatozoa or no spermatozoa, respectively) and embryosndeveloped to the blastocyst stage (8% v. 22%, 27%, 25% or 0%, respectively). These results demonstrate that porcinenspermatozoa derived from immature testis tissue xenografted into mice are fertilisation competent, albeit at a lower ratenthan testicular, epididymal or ejaculated spermatozoa from control boars, and support embryo development after ICSI.