- Email: [email protected]
Effect of nellore bull variation on embryo in vitro production
Theriogenology
348
EFFECT OF NELLORE BULL VARIATION ON EMBRYO IN VITRO PRODUCTION R.B. L6bo, M.R. Watanabe, R.A. Vila, M.A.V. Galerani, Y.F. Watanabe Department of Genetics - FMRP/USP, Av. Bandeirantes, 3900 - CEP:14040-030 Ribeir~o Preto-Sao Paulo, Brazil. The purpose of the present work was to compare the cleavage and blastocyst rates after IVF using sperm from each 12 Nellore bulls. The oocytes were recovered from ovaries at a local abattoir from Nellore cows and were matured in TCM199 bicarbonate+10% FCS+0.5gg FSH/ml+501.tg LH/ml+lgg estradiol/ml, for 24h at 38.5°C with 5% CO2 in air. Live spermatozoa were obtained by centrifugation in Percoll gradients (45 and 90%) and then transferred to fertilization drops of TALP medium + 10gg heparin/ml and spermatic concentration of 106 cells/ml. After 12 h incubation, the zygotes with cumulus cells were transferred to modified CR2 medium + 10% FCS droplets. At 58-60 h post-insemination, cleavage rate was assessed and fresh medium added (first feeding). The second feeding was made in D6 (130-132 hpi) and the number of blastocysts evaluated after D5 of development. Data were evaluated by analysis of variance using the GLM procedure of SAS. Results are summarized in Table 1. Table 1. Effect of individual nellore bulls on the cleavage rate of bovine oocytes and their subsequent development. No. of replicates: 5 Bulls
No. Oocytes Cleavage (%)" Blastocysts (%)a Hatching (%)b Inseminated 01 185 168 (91) 93 (50) 78 (84) 02 201 162 (81) 94 (47) 79 (84) 03 182 150 (82) 90 (49) 79 (88) 04 203 161 (79) 88 (43) 71 (81) 05 185 127 (69) 69 (37) 55 (80) 06 189 152 (80) 89 (47) 77 (87) 07 169 91 (54) 51 (30) 45 (88) 08 173 65 (38) 27 (16) 23 (85) 09 191 113 (59) 56 (29) 47 (84) 10 199 160 (80) 97 (49) 81 (84) 11 167 69 (41) 33 (20) 28 (85) 12 172 146 (84) 78 (45) 66 (85) Overall 2216 1564 (70) 865 (39) 729 (84) a values within the same column are significantlydifferent(P<0,000I) b values within the same column are not significantlydifferent(P>0,05) The results obtained indicate significant variation between bulls in an in vitro fertilization system, as evaluated by cleavage rate and development of zygotes to the blastocyst stage. We conclude that bull testing is important in in vitro embryo production, particularly when working with high quality donors (Financial Support: CAPES, FAPESP, F1NEP, CNPqRHAE, PMGRN).
348
EFFECT OF NELLORE BULL VARIATION ON EMBRYO IN VITRO PRODUCTION R.B. L6bo, M.R. Watanabe, R.A. Vila, M.A.V. Galerani, Y.F. Watanabe Department of Genetics - FMRP/USP, Av. Bandeirantes, 3900 - CEP:14040-030 Ribeir~o Preto-Sao Paulo, Brazil. The purpose of the present work was to compare the cleavage and blastocyst rates after IVF using sperm from each 12 Nellore bulls. The oocytes were recovered from ovaries at a local abattoir from Nellore cows and were matured in TCM199 bicarbonate+10% FCS+0.5gg FSH/ml+501.tg LH/ml+lgg estradiol/ml, for 24h at 38.5°C with 5% CO2 in air. Live spermatozoa were obtained by centrifugation in Percoll gradients (45 and 90%) and then transferred to fertilization drops of TALP medium + 10gg heparin/ml and spermatic concentration of 106 cells/ml. After 12 h incubation, the zygotes with cumulus cells were transferred to modified CR2 medium + 10% FCS droplets. At 58-60 h post-insemination, cleavage rate was assessed and fresh medium added (first feeding). The second feeding was made in D6 (130-132 hpi) and the number of blastocysts evaluated after D5 of development. Data were evaluated by analysis of variance using the GLM procedure of SAS. Results are summarized in Table 1. Table 1. Effect of individual nellore bulls on the cleavage rate of bovine oocytes and their subsequent development. No. of replicates: 5 Bulls
No. Oocytes Cleavage (%)" Blastocysts (%)a Hatching (%)b Inseminated 01 185 168 (91) 93 (50) 78 (84) 02 201 162 (81) 94 (47) 79 (84) 03 182 150 (82) 90 (49) 79 (88) 04 203 161 (79) 88 (43) 71 (81) 05 185 127 (69) 69 (37) 55 (80) 06 189 152 (80) 89 (47) 77 (87) 07 169 91 (54) 51 (30) 45 (88) 08 173 65 (38) 27 (16) 23 (85) 09 191 113 (59) 56 (29) 47 (84) 10 199 160 (80) 97 (49) 81 (84) 11 167 69 (41) 33 (20) 28 (85) 12 172 146 (84) 78 (45) 66 (85) Overall 2216 1564 (70) 865 (39) 729 (84) a values within the same column are significantlydifferent(P<0,000I) b values within the same column are not significantlydifferent(P>0,05) The results obtained indicate significant variation between bulls in an in vitro fertilization system, as evaluated by cleavage rate and development of zygotes to the blastocyst stage. We conclude that bull testing is important in in vitro embryo production, particularly when working with high quality donors (Financial Support: CAPES, FAPESP, F1NEP, CNPqRHAE, PMGRN).