Fertilization and in vitro Development of Bovine Oocytes Following Round Spermatid Injection.

Um,  J H; Do,  J T; Kim,  N H; Park,  H D; Lee,  H T; Chung,  K S

Original Article

Korean Journal of Fertility and Sterility 1999;26(2):193-201.
Published online January 1, 2001.

Fertilization and in vitro Development of Bovine Oocytes Following Round Spermatid Injection.

J H Um, J T Do, N H Kim, H D Park, H T Lee, K S Chung

Abstract

SUMMARY: In this study we determined fertilization processes and developmental ability of porcine oocytes following injection of round spermatid in the presence of artificial activation. Electrical stimulation at 3 h before spermatid injection significantly increased the incidence of normal fertilization as compared to those following injection without stimulation or with stimulation immediately after injection. The incidences of two pronuclear formation and apposition were not different in oocytes between following intracytoplasmic spermatid and spermatic nucleus injection. Indirect immunocytochemistry and laser scanning confocal microscopy study revealed that microtubules were organized from the oocyte cortex following round spermatid injection, and this seemed to move both male and female pronuclel into the oocyte center. Paternal mitochondria which are introduced with spermatid have been observed up to 4-cell. Our study indicated that either round spermatid or it's nucleus can be used to produce viable bovine embryos by injection into unfertilized oocytes.