Generating bovine embryos through ICSI

Abstract

Through ICSI, competition between sperms and also sperm-oocyte interaction are avoided thus ICSI proving reliable when sperm is not suitable for IVF. In bovine, the limiting step is represented by low rate of sperm head decondensation subsequent ICSI. Intracytoplasmatic sperm injection allows avoiding many critical moments that may occur during normal or in vitro fertilization. Oocytes were obtained from ovaries from slaughtered cows. These were transported in 0.9% NaCl solution in isothermal bags at a temperature of 25-30 ° C. The ovaries were brought from the slaughterhouse within 2 hours. Harvesting of the oocytes was made through the aspiration method. After maturation, oocytes were fertilized using sperm that was prepared using Percoll method and then treated with TritonX. The volume of the TritonX solution that accompanies the sperma and which remains in the oocyte is extremely important given that by its action, TritonX removes the acrosome, thus releasing a rich enzyme content and facilitating the dehydration of the male pronucleus. Even though the number of 2 nucleus, 2 cells or 4 cells oocytes is inferior to the data found in the literature, compared to the results achieved last year in the assisted reproduction laboratory within CLC-HC Timisoara, it marks significant progress. At the 2 cells stage, there were several oocytes from group 1 (24.39% vs. 12.5%), while at the 4 cells stage there were 14.63% oocytes from group 1 and 25% group 2. The use of TritonX solution for sperm treatment as well as shortening the duration of ICSI execution allowed us to get encouraging results. The results obtained are inferior to those presented in the literature but are far superior to those we obtained last year when the ICSI technique was assembled. Achieving the two- and four-cell embryonic stages justifies us thinking that we are mastering the ICSI technique.