RESUMO
It is well-established that in vitro culture affects quality, gene expression, and epigenetic processes in bovine embryos and that trophectoderm cells are the most susceptible to abnormalities. These changes have been reported as the main factors responsible for losses observed after transfer of in vitro-produced embryos. The present study aimed to investigate the effect of an in vitro system on bovine embryo transcriptional profiles on D14 of development. Two groups were used-one with embryos produced in vitro until D7 (day 7; VT group) and another with embryos produced in vivo by hormonal stimulation, with embryos collected on D7 (VV group). D7 embryos at similar developmental stages from both treatments were transferred to recipient uteri and recollected on D14. From D14 embryos of both treatments, trophoblast samples were removed by biopsy for sexing and transcriptome analyses. Embryos were sexed by polymerase chain reaction (PCR), and only males were used for RNA sequencing. In total, 29,005 transcripts were expressed, from which 900 were differentially expressed, but only 29 genes were significantly differentially expressed. In addition, 20 genes were found uniquely for VV and 27 for VT. These findings suggested that although the uterine environment minimized transcriptional differences, it was not able to make trophoblasts from the in vitro embryos similar to the in vivo ones. The few genes exhibiting differences are in control of important events that may be responsible for embryonic losses occurring during the first period of gestation.
Assuntos
Desenvolvimento Embrionário/genética , Epigênese Genética/genética , Transcriptoma/genética , Trofoblastos/metabolismo , Animais , Blastocisto/metabolismo , Bovinos , Transferência Embrionária/métodos , Embrião de Mamíferos , Regulação da Expressão Gênica no Desenvolvimento/genética , RNA-SeqRESUMO
DNA methylation is an essential epigenetic mark for embryo development and can be susceptible to environment factors such as in vitro conditions. The aim of this study was to verify the effect of in vitro culture until Day (D) 14 of the development on the embryo size and DNA methylation pattern of the insulin-like growth factor 2 (IGF2)-imprinted gene. To achieve this, we produced bovine embryos completely in vivo, completely in vitro, and in vitro until D7 and then in vivo up to D14. The embryos produced in in vitro were smaller than those in other two groups (p = 0.024); no differences in embryo size were observed between genders. The in vitro embryos showed a higher level of DNA methylation in the IGF2 as compared with that in the completely in vivo-produced (IVV) embryos (p = 0.009). Furthermore, totally in vitro-produced male embryos showed higher levels of DNA methylation as compared with those observed for the totally IVV male embryos (p = 0.034). No differences were observed among genders for IGF2 DNA methylation. These results showed that the window between D7 and D14 is critical for embryo development and alterations in the environmental conditions during this period can impair DNA methylation establishment of important developmental imprinted genes. This study brings unprecedented data for bovine embryos regarding the impact of the environmental conditions during the posthatching development.
Assuntos
Metilação de DNA , Técnicas de Cultura Embrionária/métodos , Embrião de Mamíferos/citologia , Desenvolvimento Embrionário/genética , Impressão Genômica , Fator de Crescimento Insulin-Like II/genética , Trofoblastos/citologia , Animais , Bovinos , Transferência Embrionária , Embrião de Mamíferos/metabolismo , Feminino , Técnicas In Vitro , Masculino , Trofoblastos/metabolismoRESUMO
A torção de útero em bovinos é um caso de emergência obstétrica que, na maioria das vezes, leva à morte do feto e da mãe. O tratamento clínico é pouco eficaz e em grande parte dos casos a operação cesariana é indicada. O trabalho descreve o caso de uma vaca Nelore de 36 meses encaminhada ao Hospital Escola de Grandes Animais da Universidade de Brasília com torção uterina e sinais de toxemia. Após tentativas improdutivas de rolamento, o animal foi submetido à cesariana e veio a morrer durante o procedimento cirúrgico. Vários casos de torção de útero em bovinos são descritos em raças europeias, porém, pouco se conhece desse tipo de patologia em animais da raça Nelore.(AU)
Uterus torsion in cows is an emergency case that usually leads to foetus and cow death. Conservative management has low efficacy and cesarian surgery is indicated in the majority of the cases. The report describes the case of a 36-year-old Nellore cow taken to Hospital Escola de Grandes Animais of Universidade de Brasíla with uterus torsion and toxemia signs. After improductive rolling procedures, the animal was lead to a cesarian surgery and died during the procedure. Uterus torsion is described in european breeds, but this patology is not well-known in Nellore cattle.(AU)
Assuntos
Animais , Feminino , Gravidez , Bovinos , Anormalidade Torcional/veterinária , Útero/cirurgia , Procedimentos Cirúrgicos Obstétricos/veterinária , Útero/patologia , Complicações na Gravidez/veterinária , BovinosRESUMO
A torção de útero em bovinos é um caso de emergência obstétrica que, na maioria das vezes, leva à morte do feto e da mãe. O tratamento clínico é pouco eficaz e em grande parte dos casos a operação cesariana é indicada. O trabalho descreve o caso de uma vaca Nelore de 36 meses encaminhada ao Hospital Escola de Grandes Animais da Universidade de Brasília com torção uterina e sinais de toxemia. Após tentativas improdutivas de rolamento, o animal foi submetido à cesariana e veio a morrer durante o procedimento cirúrgico. Vários casos de torção de útero em bovinos são descritos em raças europeias, porém, pouco se conhece desse tipo de patologia em animais da raça Nelore.
Uterus torsion in cows is an emergency case that usually leads to foetus and cow death. Conservative management has low efficacy and cesarian surgery is indicated in the majority of the cases. The report describes the case of a 36-year-old Nellore cow taken to Hospital Escola de Grandes Animais of Universidade de Brasíla with uterus torsion and toxemia signs. After improductive rolling procedures, the animal was lead to a cesarian surgery and died during the procedure. Uterus torsion is described in european breeds, but this patology is not well-known in Nellore cattle.