The role of L-carnitine in bovine embryo metabolism. A review of the effect of supplementation with a metabolic modulator on in vitro embryo production.

Early embryo development is driven first by the maternal RNAs and proteins accumulated during the oocyte's cytoplasmic maturation and then after the embryo genome activation. In mammalian cells, ATP generation occurs via oxidative pathways or by glycolysis, whereas in embryonic stem cells, the consumption of glucose, pyruvate, lipids, and amino acids results in ATP synthesis. Although the bovine embryo has energy reserves in glycogen and lipids, the glycogen concentration is deficient. Conversely, lipids represent the most abundant energy reservoir of bovine embryos, where lipid droplets-containing triacylglycerols are the main fatty acid stores. Oocytes of many mammalian species contain comparatively high amounts of lipids stored as droplets in the ooplasm. L-carnitine has been described as a cofactor that facilitates the mobilization of fatty acids present in the oocyte's cytoplasm into the mitochondria to facilitate ß-oxidation processes. However, the L-carnitine effects by addition to media in the in vitro produced embryos on the quality are highly disputed and contradictory by different researchers. This review's objective was to explore the effect that the addition of L-carnitine on culture media could have on the overall bovine embryo production in vitro, from the oocyte metabolism to the modulation of gene expression in the developing embryos.

Evaluation of fertilization capability of frozen-thawed completely immotile spermatozoa collected from a white bengal tiger after interspecific ICSI with bovine oocytes.

The objective of this study was to evaluate the fertilization capability of White Bengal Tiger frozen-thawed completely immotile spermatozoa after interspecific intracytoplasmic sperm injection (ICSI) with bovine oocytes. The fertilization status of presumptive zygotes was assessed 18 h after ICSI by immunofluorescence staining and confocal microscopy. The fertilization rate was 34.8% (8/23), as confirmed by the extrusion of two polar bodies, or male and female pronuclei formation. For unfertilized oocytes (65.2%, 15/23), one activated oocyte had an activated spermatozoon but most were unactivated oocytes with unactivated spermatozoa (1/15, 6.7% vs 10/15, 66.7%, respectively, p < 0.05). These results showed that White Bengal Tiger frozen-thawed completely immotile spermatozoa retained the capacity to fertilize bovine oocytes after interspecific ICSI. This is the first report of in vitro produced zygotes using tiger immotile sperm with bovine oocytes by interspecific ICSI technique, which provides an efficient and feasible method for preservation and utilization of endangered feline animals.

Dynamics of nuclear and cytoplasm maturation of bovine oocytes cultivated in vitro in medium supplemented with fulerol / Dinâmica da maturação nuclear e citoplasmática de oócitos bovinos cultivados in vitro em meio suplementado com fulerol

The aim of this work was to evaluate, in vitro, the dynamics of nuclear and cytoplasmic maturation of bovine oocytes in traditional IVM medium (CT) and supplemented with fullerol (MF50), for 36 hours. The nuclear maturation of CT (n=300) and MF50 (n=270) every 6 hours, stained with Hoechst33342 and cytoplasmic, the mitochondrial distribution of CT (n=197) and MF50 (n=159) at every 12 hours, stained with Mitotracker Orange. At 6 hours, CT oocytes (19%) were in MI (metaphase I), while in MF50 they were in GV (germ vesicle) or GVB (GV breakeage), repeating at 12 hours. At 18 hours, 46.3% were matured in CT, and 20% in MF50. At 24 hours, 43.9% of maturation was observed in the MF50 group, and 63.8% in the CT. At 30 and 36 hours, the maturation pattern was stable, but with the onset of oocyte degeneration. There was a delay in cytoplasmic maturation with 36 hours (P < 0.05) in MF50 (53.9% of mature gametes), compared to CT (69.8%). With immature cytoplasm, they were 10.4% and 31.7% for CT and MF50 (P< 0.05), respectively. It was concluded that fullerol possibly interfered in the expansion of cumulus oophorus cells, as well as delayed the meiotic progression and cytoplasmic maturation.

O objetivo deste estudo foi avaliar, in vitro, a dinâmica da maturação nuclear e citoplasmática de oócitos bovinos em meio MIV tradicional (TC) e suplementado com fulerol (MF50), durante 36 horas. Na maturação nuclear do TC (n=300) e do MF50 (n=270) a cada seis horas, corados com Hoechst 33342, e na citoplasmática, avaliou-se a distribuição mitocondrial do TC (n=197) e do MF50 (n=159) a cada 12 horas, corados com Mitotracker Orange (Life® Technologies). Às seis horas, oócitos do TC (19%) se encontravam em MI (metáfase I), enquanto no MF50 estavam em VG (vesícula germinativa) ou QVG (quebra VG), repetindo com 12 horas. Às 18 horas, 46,3% estavam maturados no TC, e 20% no MF50. Com 24 horas, verificaram-se 43,9% de maturação no grupo MF50, e 63,8% no TC. Às 30 e 36 horas, o padrão de maturação foi estável, mas com início de degeneração oócitária. Houve retardo na maturação citoplasmática com 36 horas (P<0,05) no MF50 (53,9% de gametas maduros), comparado ao TC (69,8%). Com citoplasma imaturo, foram 10,4% e 31,7% para TC e MF50 (P<0,05), respectivamente. Conclui-se que o fulerol possivelmente interferiu na expansão das células do cumulus oophorus, bem como retardou a progressão meiótica e a maturação citoplasmática dos oócitos.

Evaluation of fertilization capability of frozen-thawed completely immotile spermatozoa collected from a white bengal tiger after interspecific ICSI with bovine oocytes

The objective of this study was to evaluate the fertilization capability of White Bengal Tiger frozen-thawed completely immotile spermatozoa after interspecific intracytoplasmic sperm injection (ICSI) with bovine oocytes. The fertilization status of presumptive zygotes was assessed 18 h after ICSI by immunofluorescence staining and confocal microscopy. The fertilization rate was 34.8% (8/23), as confirmed by the extrusion of two polar bodies, or male and female pronuclei formation. For unfertilized oocytes (65.2%, 15/23), one activated oocyte had an activated spermatozoon but most were unactivated oocytes with unactivated spermatozoa (1/15, 6.7% vs 10/15, 66.7%, respectively, p < 0.05). These results showed that White Bengal Tiger frozen-thawed completely immotile spermatozoa retained the capacity to fertilize bovine oocytes after interspecific ICSI. This is the first report of in vitro produced zygotes using tiger immotile sperm with bovine oocytes by interspecific ICSI technique, which provides an efficient and feasible method for preservation and utilization of endangered feline animals.(AU)

Corpora lutea affect in vitro maturation of bovine cumulus-oocyte complexes and embryonic development after fertilization with sex-sorted or conventional semen.

Influence of both the presence of a corpus luteum on the ovary and semen sex-sorting on development following in vitro fertilization is not yet conclusive. To determine the effect of these factors, 376 bovine oocytes were processed in vitro according to luteal presence on the ovary (CL+ and CL-) and type of semen used (sexed or conventional). Maturation rate was higher (P < 0.01) in CL- (136/138; 98.6%) than in CL+ (217/238; 91.2%). Cleavage rate was lower (P < 0.01) in CL+ with sexed semen (60/172; 34.9%) than in CL- with sexed semen (42/71; 59.1%), CL+ with conventional semen (47/66; 71.2%), and CL- with conventional semen (54/67; 85.1%). Compaction was similar (P = 0.69) in CL- (49/99; 49.4%) and CL+ (50/107; 46.7%). Blastulation rate was higher (P < 0.01) in CL- (26/99, 26.2%) than in CL+ (13/107; 12.1%) group. Expansion rate was higher (P = 0.01) in CL- (22/99; 22%) than in CL+ (11/107; 10.2%) group. Compaction rates were similar (P = 0.78) in sex-sorted (50/102; 49.0%) or conventional semen (49/104; 47.1%) groups. Blastulation was also similar (P = 0.91) with sex-sorted semen (19/102; 18.6%) and conventional semen (20/104; 19.2%). The rate of expanded blastocysts was similar (P = 0.89) in sex-sorted (16/102; 15.6%) and conventional (17/104; 16.3%) semen groups. In conclusion, the presence of CL can compromise maturation of the oocytes and their development, as a higher proportion of cleavage-stage embryos can be obtained with non-sexed semen with oocytes from ovaries without a CL.

Goat incubator: Can bovine oocytes be matured in the uterine horn of a goat? / Cabra incubadora: os oócitos bovinos podem ser maturados no corno uterino de uma cabra?

We used a goat as a live incubator, along with associated nonsurgical embryo transfer techniques, to perform ex situ (in vivo) maturation of bovine oocytes. Immature bovine cumulus-oocyte complexes (COCs) aspirated from 3-8 mm follicles from slaughterhouse ovaries were randomly split into two groups for in vitro (IVM; n = 38) and ex situ maturation (ESM; n = 40). IVM was performed for a period of 24 h at 38.5 ºC and with 5% CO2 in the air of maximum humidity. For ESM, a presynchronized nulliparous goat (12 months old) received 40 immature COCs in the uterine horn apiece, via the transcervical route. After 24 h the structures were retrieved through uterine flushing. Analyses of nuclear maturation and lipid quantification were performed on oocytes from both groups. Fluorescent intensity was compared using the Student’s t-test. Forty-seven percent of the structures were recovered after uterine flushing (19/40). The nuclear maturation rate was 94.5% (18/19) and 81.6% (31/38) for the ESM and IVM groups, respectively. In vitro-matured COCs contained more lipid droplets, expressed as a higher amount (p < 0.05) of emitted fluorescent light than ex situ-matured COCs (858 ± 73 vs. 550 ± 64 arbitrary fluorescence units, respectively). This is the first report to associate nonsurgical embryo transfer techniques and a goat as a live incubator for the maturation of bovine oocytes. We

Utilizamos uma cabra como incubadora viva, juntamente com técnicas de transferência de embriões não cirúrgicas associadas, para realizar a maturação ex situ (in vivo) de oócitos bovinos. Os complexos cumulus-oócitos bovinos (COCs), aspirados de folículos de 3-8 mm de ovários de abatedouro foram aleatoriamente divididos em dois grupos para maturação in vitro (IVM; n = 38) e ex situ (ESM; n = 40). A MIV foi realizada por um período de 24 h no meio TCM-199, a 38,5 ºC, e com 5% de CO2 em umidade máxima. Para o ESM, uma cabra nulípara pré-sincronizada (12 meses de idade) recebeu 40 COCs imaturos no ápice do corno uterino, por via transcervical. Após 24 h as estruturas foram recuperadas através de lavagem uterina. Análises de maturação nuclear e quantificação de lipídios foram realizadas em oócitos de ambos os grupos. A intensidade de fluorescente foi comparada usando o teste t de Student. Quarenta e sete por cento das estruturas foram recuperadas após lavagem uterina (19/40). A taxa de maturação nuclear foi de 94,5% (18/19) e 81,6% (31/38) para os grupos ESM e IVM, respectivamente. Os COCs maturados in vitro continham mais gotículas lipídicas, expressos como uma quantidade maior (p < 0,05) da luz fluorescente emitida do que os COCs ex situ (858 ± 73 vs 550 ± 64 unidades de fluorescência arbitrárias, respectivamente). Este é o primeiro relató

Goat incubator: Can bovine oocytes be matured in the uterine horn of a goat? / Cabra incubadora: os oócitos bovinos podem ser maturados no corno uterino de uma cabra?

We used a goat as a live incubator, along with associated nonsurgical embryo transfer techniques, to perform ex situ (in vivo) maturation of bovine oocytes. Immature bovine cumulus-oocyte complexes (COCs) aspirated from 3-8 mm follicles from slaughterhouse ovaries were randomly split into two groups for in vitro (IVM; n = 38) and ex situ maturation (ESM; n = 40). IVM was performed for a period of 24 h at 38.5 ºC and with 5% CO2 in the air of maximum humidity. For ESM, a presynchronized nulliparous goat (12 months old) received 40 immature COCs in the uterine horn apiece, via the transcervical route. After 24 h the structures were retrieved through uterine flushing. Analyses of nuclear maturation and lipid quantification were performed on oocytes from both groups. Fluorescent intensity was compared using the Student’s t-test. Forty-seven percent of the structures were recovered after uterine flushing (19/40). The nuclear maturation rate was 94.5% (18/19) and 81.6% (31/38) for the ESM and IVM groups, respectively. In vitro-matured COCs contained more lipid droplets, expressed as a higher amount (p < 0.05) of emitted fluorescent light than ex situ-matured COCs (858 ± 73 vs. 550 ± 64 arbitrary fluorescence units, respectively). This is the first report to associate nonsurgical embryo transfer techniques and a goat as a live incubator for the maturation of bovine oocytes. We

Utilizamos uma cabra como incubadora viva, juntamente com técnicas de transferência de embriões não cirúrgicas associadas, para realizar a maturação ex situ (in vivo) de oócitos bovinos. Os complexos cumulus-oócitos bovinos (COCs), aspirados de folículos de 3-8 mm de ovários de abatedouro foram aleatoriamente divididos em dois grupos para maturação in vitro (IVM; n = 38) e ex situ (ESM; n = 40). A MIV foi realizada por um período de 24 h no meio TCM-199, a 38,5 ºC, e com 5% de CO2 em umidade máxima. Para o ESM, uma cabra nulípara pré-sincronizada (12 meses de idade) recebeu 40 COCs imaturos no ápice do corno uterino, por via transcervical. Após 24 h as estruturas foram recuperadas através de lavagem uterina. Análises de maturação nuclear e quantificação de lipídios foram realizadas em oócitos de ambos os grupos. A intensidade de fluorescente foi comparada usando o teste t de Student. Quarenta e sete por cento das estruturas foram recuperadas após lavagem uterina (19/40). A taxa de maturação nuclear foi de 94,5% (18/19) e 81,6% (31/38) para os grupos ESM e IVM, respectivamente. Os COCs maturados in vitro continham mais gotículas lipídicas, expressos como uma quantidade maior (p < 0,05) da luz fluorescente emitida do que os COCs ex situ (858 ± 73 vs 550 ± 64 unidades de fluorescência arbitrárias, respectivamente). Este é o primeiro relató

Goat incubator: Can bovine oocytes be matured in the uterine horn of a goat? / Cabra incubadora: os oócitos bovinos podem ser maturados no corno uterino de uma cabra?

We used a goat as a live incubator, along with associated nonsurgical embryo transfer techniques, to perform ex situ (in vivo) maturation of bovine oocytes. Immature bovine cumulus-oocyte complexes (COCs) aspirated from 3-8 mm follicles from slaughterhouse ovaries were randomly split into two groups for in vitro (IVM; n = 38) and ex situ maturation (ESM; n = 40). IVM was performed for a period of 24 h at 38.5 ºC and with 5% CO2 in the air of maximum humidity. For ESM, a presynchronized nulliparous goat (12 months old) received 40 immature COCs in the uterine horn apiece, via the transcervical route. After 24 h the structures were retrieved through uterine flushing. Analyses of nuclear maturation and lipid quantification were performed on oocytes from both groups. Fluorescent intensity was compared using the Student’s t-test. Forty-seven percent of the structures were recovered after uterine flushing (19/40). The nuclear maturation rate was 94.5% (18/19) and 81.6% (31/38) for the ESM and IVM groups, respectively. In vitro-matured COCs contained more lipid droplets, expressed as a higher amount (p < 0.05) of emitted fluorescent light than ex situ-matured COCs (858 ± 73 vs. 550 ± 64 arbitrary fluorescence units, respectively). This is the first report to associate nonsurgical embryo transfer techniques and a goat as a live incubator for the maturation of bovine oocytes. We

Utilizamos uma cabra como incubadora viva, juntamente com técnicas de transferência de embriões não cirúrgicas associadas, para realizar a maturação ex situ (in vivo) de oócitos bovinos. Os complexos cumulus-oócitos bovinos (COCs), aspirados de folículos de 3-8 mm de ovários de abatedouro foram aleatoriamente divididos em dois grupos para maturação in vitro (IVM; n = 38) e ex situ (ESM; n = 40). A MIV foi realizada por um período de 24 h no meio TCM-199, a 38,5 ºC, e com 5% de CO2 em umidade máxima. Para o ESM, uma cabra nulípara pré-sincronizada (12 meses de idade) recebeu 40 COCs imaturos no ápice do corno uterino, por via transcervical. Após 24 h as estruturas foram recuperadas através de lavagem uterina. Análises de maturação nuclear e quantificação de lipídios foram realizadas em oócitos de ambos os grupos. A intensidade de fluorescente foi comparada usando o teste t de Student. Quarenta e sete por cento das estruturas foram recuperadas após lavagem uterina (19/40). A taxa de maturação nuclear foi de 94,5% (18/19) e 81,6% (31/38) para os grupos ESM e IVM, respectivamente. Os COCs maturados in vitro continham mais gotículas lipídicas, expressos como uma quantidade maior (p < 0,05) da luz fluorescente emitida do que os COCs ex situ (858 ± 73 vs 550 ± 64 unidades de fluorescência arbitrárias, respectivamente). Este é o primeiro relató

Tretinoin-loaded lipid-core nanocapsules decrease reactive oxygen species levels and improve bovine embryonic development during in vitro oocyte maturation.

In vitro oocyte maturation (IVM) protocols can be improved by adding chemical supplements to the culture media. Tretinoin is considered an important retinoid in embryonic development and its association with lipid-core nanocapsules (TTN-LNC) represents an innovative way of improving its solubility, and chemical stability, and reducing its toxicity. The effects of supplementing IVM medium with TTN-LNC was evaluated by analyzing production of reactive oxygen species (ROS), S36-phosphorilated-p66Shc levels and caspase activity in early embryonic development, and expression of apoptosis and pluripotency genes in blastocysts. The lowest concentration tested (0.25µM) of TTN-LNC generated higher blastocyst rate, lower ROS production and S36-p66Shc amount. Additionally, expression of BAX and SHC1 were lower in both non-encapsulated tretinoin (TTN) and TTN-LNC-treated groups. Nanoencapsulation allowed the use of smaller concentrations of tretinoin to supplement IVM medium thus reducing toxic effects related with its use, decreasing ROS levels and apoptose frequency, and improving the blastocyst rates.

Transporte de oócitos bovinos em meio de maturação sem controle de atmosfera gasosa

Oocytes (n=1177) aspirated from 2 to 8mm follicles obtained from bovine slaughterhouse ovaries (11 replications) were randomly distributed in four treatments. Oocytes were matured for 24h with modified TCM-199 Earle salts, plus 25mM bicarbonate, 25 mM HEPES, rFSH-h, Estrus Cow Serum (ECS), and piruvate at 39ºC, in incubator with 5% CO2 and saturated humidity (Control Group, n=296) or exposed to a simulated transport for 6 (T6, n=286), 12 (T12, n=294) or 18h (T18, n=301) in maturation medium containing TCM + HEPES, in a 39ºC water bath, with the same components used in the Control Group, but with 1mM bicarbonate. At the conclusion of each transport period, oocytes were transferred to dishes with maturation medium to reach 24h in incubator, under the same conditions described for the Control group. Fertilization was accomplished during 18h, with the same temperature and gaseous atmosphere, in FERT-TALP plus heparin. The insemination dose was 1x106 spermatozoa/mL, sorted by swim-up. Presumptive zygotes were cultured in SOF medium + 5% ECS for 8 days, in incubator at 39ºC using gasified bags with 5% CO2, 5% O2 and 90% N2. Cleavage rates did not differ between treatments. Embryonic development rates at D7 were similar for Control (20.9%), T6 (19.2%) and T12 (21.4%) groups, with a reduction (P 0.05) for group T18 (12.3%) when compared to Control and T12 groups. At D9, there was a lower production of expanded plus hatched blastocysts in T18 (P 0.05), without difference (P>0.05) in hatched blastocyst rate. The average number of cells of hatched blastocysts was similar (P>0.05) in Control (136), T6 (125.5) and T12 (126.8) groups. These results indicate the possibility of transporting bovine oocytes in maturation medium containing TCM + HEPES, without controlled gaseous atmosphere environment, at 39ºC, for up to 12 hours. This technique offers a practical and efficient alternative for the transport of bovine oocytes for in vitro production of bovine embryos (IVP).

Oócitos (n=1177) bovinos obtidos da aspiração de folículos com diâmetro entre 2 e 8mm, de ovários de matadouro foram divididos aleatoriamente em quatro tratamentos com 11 repetições. Os oócitos foram maturados por 24h em TCM-199 Sais de Earle, acrescido de 25mM de bicarbonato de sódio, 25mM de HEPES, rFHS-h, Soro de Vaca em Estro (SVE) e piruvato, em estufa a 39ºC, com 5% de CO2 em ar e umidade saturada (Grupo Controle, n=296) ou, submetidos ao transporte simulado por 6 (T6, n=286), 12 (T12, n=294) ou 18h (T18, n=301) em meio de maturação TCM+HEPES, em banho-maria a 39ºC, com os mesmos componentes utilizados para o Grupo Controle, porém com apenas 1mM de bicarbonato. Decorrido cada período de transporte, os mesmos foram transferidos para placas com meio de maturação, completando o período de 24h em estufa, nas mesmas condições do Grupo Controle. O período de fecundação foi de 18h em condições semelhantes de temperatura e atmosfera gasosa, em FERT-TALP acrescido de heparina, sendo a dose inseminante de 1x106 espermatozóides/mL, selecionados por migração ascendente. Os prováveis zigotos foram cultivados em meio SOF + 5% SVE por 8 dias, em estufa a 39ºC, em bolsas gaseificadas com 5% CO2, 5% O2 e 90% N2. Na avaliação da clivagem, não houve diferença entre os tratamentos. As taxas de desenvolvimento embrionário no dia 7 foram semelhantes para os grupos Controle (20,9%), T6 (19,2%) e T12 (21,4%), com uma redução (P 0,05) observada no grupo T18 (12,3%), em relação aos grupos Controle e T12. No dia 9, o T18 apresentou uma menor (P 0,05) produção de blastocistos expandidos mais eclodidos, em relação aos demais grupos, embora não tenha sido observada diferença (P>0,05) na taxa de eclosão. O número médio de células dos blastocistos eclodidos não diferiu (P>0,05) entre os grupos Controle (136), T6 (125,5) e T12 (126,8). Esses resultados indicam a possibilidade do transporte de oócitos bovinos em meio de maturação TCM+HEPES, sem controle da atmosfera gasosa, a 39ºC, pelo período de até 12h. Esta técnica oferece uma alternativa prática e eficiente para o transporte dos oócitos bovinos destinados à produção in vitro de embriões bovinos (PIV).

Transporte de oócitos bovinos em meio de maturação sem controle de atmosfera gasosa

Oocytes (n=1177) aspirated from 2 to 8mm follicles obtained from bovine slaughterhouse ovaries (11 replications) were randomly distributed in four treatments. Oocytes were matured for 24h with modified TCM-199 Earle salts, plus 25mM bicarbonate, 25 mM HEPES, rFSH-h, Estrus Cow Serum (ECS), and piruvate at 39ºC, in incubator with 5% CO2 and saturated humidity (Control Group, n=296) or exposed to a simulated transport for 6 (T6, n=286), 12 (T12, n=294) or 18h (T18, n=301) in maturation medium containing TCM + HEPES, in a 39ºC water bath, with the same components used in the Control Group, but with 1mM bicarbonate. At the conclusion of each transport period, oocytes were transferred to dishes with maturation medium to reach 24h in incubator, under the same conditions described for the Control group. Fertilization was accomplished during 18h, with the same temperature and gaseous atmosphere, in FERT-TALP plus heparin. The insemination dose was 1x106 spermatozoa/mL, sorted by swim-up. Presumptive zygotes were cultured in SOF medium + 5% ECS for 8 days, in incubator at 39ºC using gasified bags with 5% CO2, 5% O2 and 90% N2. Cleavage rates did not differ between treatments. Embryonic development rates at D7 were similar for Control (20.9%), T6 (19.2%) and T12 (21.4%) groups, with a reduction (P 0.05) for group T18 (12.3%) when compared to Control and T12 groups. At D9, there was a lower production of expanded plus hatched blastocysts in T18 (P 0.05), without difference (P>0.05) in hatched blastocyst rate. The average number of cells of hatched blastocysts was similar (P>0.05) in Control (136), T6 (125.5) and T12 (126.8) groups. These results indicate the possibility of transporting bovine oocytes in maturation medium containing TCM + HEPES, without controlled gaseous atmosphere environment, at 39ºC, for up to 12 hours. This technique offers a practical and efficient alternative for the transport of bovine oocytes for in vitro production of bovine embryos (IVP).

Oócitos (n=1177) bovinos obtidos da aspiração de folículos com diâmetro entre 2 e 8mm, de ovários de matadouro foram divididos aleatoriamente em quatro tratamentos com 11 repetições. Os oócitos foram maturados por 24h em TCM-199 Sais de Earle, acrescido de 25mM de bicarbonato de sódio, 25mM de HEPES, rFHS-h, Soro de Vaca em Estro (SVE) e piruvato, em estufa a 39ºC, com 5% de CO2 em ar e umidade saturada (Grupo Controle, n=296) ou, submetidos ao transporte simulado por 6 (T6, n=286), 12 (T12, n=294) ou 18h (T18, n=301) em meio de maturação TCM+HEPES, em banho-maria a 39ºC, com os mesmos componentes utilizados para o Grupo Controle, porém com apenas 1mM de bicarbonato. Decorrido cada período de transporte, os mesmos foram transferidos para placas com meio de maturação, completando o período de 24h em estufa, nas mesmas condições do Grupo Controle. O período de fecundação foi de 18h em condições semelhantes de temperatura e atmosfera gasosa, em FERT-TALP acrescido de heparina, sendo a dose inseminante de 1x106 espermatozóides/mL, selecionados por migração ascendente. Os prováveis zigotos foram cultivados em meio SOF + 5% SVE por 8 dias, em estufa a 39ºC, em bolsas gaseificadas com 5% CO2, 5% O2 e 90% N2. Na avaliação da clivagem, não houve diferença entre os tratamentos. As taxas de desenvolvimento embrionário no dia 7 foram semelhantes para os grupos Controle (20,9%), T6 (19,2%) e T12 (21,4%), com uma redução (P 0,05) observada no grupo T18 (12,3%), em relação aos grupos Controle e T12. No dia 9, o T18 apresentou uma menor (P 0,05) produção de blastocistos expandidos mais eclodidos, em relação aos demais grupos, embora não tenha sido observada diferença (P>0,05) na taxa de eclosão. O número médio de células dos blastocistos eclodidos não diferiu (P>0,05) entre os grupos Controle (136), T6 (125,5) e T12 (126,8). Esses resultados indicam a possibilidade do transporte de oócitos bovinos em meio de maturação TCM+HEPES, sem controle da atmosfera gasosa, a 39ºC, pelo período de até 12h. Esta técnica oferece uma alternativa prática e eficiente para o transporte dos oócitos bovinos destinados à produção in vitro de embriões bovinos (PIV).