The effect of sperm selection by Percoll or swim-up on the sex ratio of in vitro produced bovine embryos

The goal of this investigation was to determine the percentage of male and female bovine embryos produced after oocyte fertilization with Percoll density gradient centrifugation or with self-migration (swim-up) selected semen. In Experiment 1, sperm selection was performed by 90-45% discontinuous Percoll density gradient centrifugation (T1) and swim-up (T2). InExperiment 2, in addition to the discontinuous gradient, a 67.5% continuous gradient, and 5 or 10 min centrifugation were used. Four treatment groups were defined (TI = continuous, 5 min, TII = discontinuous, 5 min, TIII = continuous, 10 min and TIV = discontinuous,10 min). Embryos were sexed using PCR. In Experiment 1,Percoll density gradient centrifugation (n = 185) resulted in 48.6% (n = 90) male and 51.4% (n = 95) female embryos, and swim-up (n = 142) in 58.4% (n = 83) male and 41.6% (n = 59) female embryos. In Experiment 2, the percentages of male and female embryos obtained in TI (n = 93), TII (n = 70), TIII (n = 82) and TIV (n = 82) were 49.5% (n = 46) and 50.5% (n = 47), 57.1% (n = 40) and 42.9% (n = 30), 36.6% (n = 30) and 63.4% (n = 52) and 48.8% (n = 40) and 51.2% (n = 42), respectively. Swim-up (T2) and continuous Percoll gradient centrifugation for 10 min (TIII) showed a deviation toward males (P = 0.044) and females (P = 0.015), respectively, when compared to the 50% expected percentage of each gender. There was no difference in male and female percentages in the other treatment groups from Experiments 1 and 2, when compared to the 50% expected percentage of each gender neither between treatment.(AU)

The effect of sperm selection by Percoll or swim-up on the sex ratio of in vitro produced bovine embryos

The goal of this investigation was to determine the percentage of male and female bovine embryos produced after oocyte fertilization with Percoll density gradient centrifugation or with self-migration (swim-up) selected semen. In Experiment 1, sperm selection was performed by 90-45% discontinuous Percoll density gradient centrifugation (T1) and swim-up (T2). InExperiment 2, in addition to the discontinuous gradient, a 67.5% continuous gradient, and 5 or 10 min centrifugation were used. Four treatment groups were defined (TI = continuous, 5 min, TII = discontinuous, 5 min, TIII = continuous, 10 min and TIV = discontinuous,10 min). Embryos were sexed using PCR. In Experiment 1,Percoll density gradient centrifugation (n = 185) resulted in 48.6% (n = 90) male and 51.4% (n = 95) female embryos, and swim-up (n = 142) in 58.4% (n = 83) male and 41.6% (n = 59) female embryos. In Experiment 2, the percentages of male and female embryos obtained in TI (n = 93), TII (n = 70), TIII (n = 82) and TIV (n = 82) were 49.5% (n = 46) and 50.5% (n = 47), 57.1% (n = 40) and 42.9% (n = 30), 36.6% (n = 30) and 63.4% (n = 52) and 48.8% (n = 40) and 51.2% (n = 42), respectively. Swim-up (T2) and continuous Percoll gradient centrifugation for 10 min (TIII) showed a deviation toward males (P = 0.044) and females (P = 0.015), respectively, when compared to the 50% expected percentage of each gender. There was no difference in male and female percentages in the other treatment groups from Experiments 1 and 2, when compared to the 50% expected percentage of each gender neither between treatment.