A novel method for detection of chromosomal integrity in cryopreserved livestock spermatozoa using artificially fused mouse oocytes

AuthorPurpose: The aim of the present study was to investigate the effect of mouse oocyte volume on the efficiency of chromosomal analysis in livestock spermatozoa. Methods: Oocytes were injected with bull, ram, boar and dog sperm heads, and then fused with enucleated mouse oocytes. Results: The increment of oocyte volume increased the rates of morphologically normal oocytes after sperm injection, which induced much higher rates of overall chromosome detection in bull, ram and dog spermatozoa. The recipient oocyte volume did not affect the chromosomal integrity. Furthermore, in bull, the chromosomal integrity detected by fused mouse oocytes was similar to that derived from a homologous system. On the other hand, chromosomal plates of boar spermatozoa could not be detected despite the use of fused oocytes. Conclusion: These data indicate that fused mouse oocytes improved the efficiency of chromosome detection in bull, ram and dog spermatozoa