Cinética da maturação nuclear in vitro de oócitos bubalinos

Com o objetivo de avaliar a cinética da maturação in vitro de oócitos bubalinos, foram cultivados 1.619 oócitos com cumulus oophorus compacto em quatro diferentes tratamentos: T1 - TCM 199 com 10% de Soro Fetal Bovino (SFB) (meio base); T2 - Meio base e células da granulosa (CG); T3 - Meio base, CG, 10 UI de gonadotrofina coriônica equina (eCG) e 10 UI de gonadotrofina coriônica humana (hCG); T4 - Meio base, 10 UI de eCG, 10UI de hCG e 1 µg de 17b-estradiol / ml, em tempos de 14 a 17h, 20 a 22h, 23 a 25h, 26 a 28h, 29h e 32h de cultivo em estufa de CO₂ a 5% e temperatura de 38,5ºC. No tratamento 1, observou-se que 81,83%, 69,61%, 65,88%, 60,28%, 64,98% e 67,67% dos ovócitos reiniciaram a meiose. No tratamento 2, as taxas de reinicio da meiose foram de 76,06%, 72,06%, 69,78%, 68,12%,74,97% e 89,96%, no tratamento 3 estes percentuais foram de 83,59%, 78,86%, 77,49%, 82,4%, 72,92% e 81,06% e com o tratamento 4 os índices foram de 95,0%, 91,82%, 93, 17%, 91,65%, 92,09% e 74,99% nos tempos de 14 a 17h, 20 a 22h, 23 a 25h, 26 a 28h, 29h e 32h de cultivo, respectivamente, podendo-se concluir que o meio com maior suplementação proporciona maior taxa de reinício da meiose em menor tempo, assim como o aumento no tempo de cultivo pode levar a maiores índices de degeneração.

ABSTRACT: To evaluate the kinetics of the in vitro maturation of buffalo oocytes, 1.619 oocytes with compact cumulus oophorus were cultivated in different treatments: T1 - TCM 199 with 10% of bovine foetal serum (BFS) (basic medium); T2 – Medium basic and granulosa cells (GC); T3 –Basic medium, GC, 10 IU of eCG and 10 IU of hCG; T4 – Basic medium , 10 IU of eCG, 10 IU of hCG and 1 µg 17b-estradiol / ml, in times 14 to 17 h, 20 to 22 h, 23 to 25 h, 26 to 28 h, 29 h and 32 h of cultivation in CO₂ incubator at 5% and temperature of 38,5ºC. In the treatment 1, it was observed that 81,83%, 69,61%, 65,88%, 60,28%, 64,98% and 67,67% of the oocytes restarted the meiosis; with the treatment 2, rates of oocytes restart of the meiosis were of 76,06%, 72,06%, 69,78%, 68,12%,74,97% and 89,96%; with the treatment 3 rates were of 83,59%, 78,86%, 77,49%, 82,4%, 72,92% and 81,06% and with the treatment 4 the rates were of 95,0%, 91,82%, 93, 17%, 91,65%, 92,09% and 74,99% in the times from 14 to 17 h, 20 to 22 h, 23 to 25 h, 26 to 28 h, 29 h and 32 h of culture, respectively, could be concluded that the supllemented medium provides larger rates of restarted of the meiosis in smaller time, as well as the increase in the time of cultivation it can take to largest rates of degeneration.