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This study aims to evaluate if a pre-maturation culture (PMC) using cilostamide as a meiotic inhibitor in combination with insulin, transferrin and selenium (ITS) for 8 or 24 h increases in vitro embryo production. To evaluate the effects of PMC on embryo development, cleavage rate, blastocyst rate, embryo size and total cell number were determined. When cilostamide (20 μM) was used in PMC for 8 or 24 h, 98% of oocytes were maintained in germinal vesicles. Although the majority of oocytes resumed meiosis after meiotic arrest, the cleavage and blastocyst rates were lower than the control (P 0.05) to the control. The deleterious effect of 20 μM cilostamide treatment for 24 h on a PMC was confirmed by lower cumulus cell viability, determined by trypan blue staining, in that group compared with the other groups. A lower concentration (10 μM) and shorter exposure time (8 h) minimized that effect but did not improve embryo production. More studies should be performed to determine the best concentration and the arresting period to increase oocyte competence and embryo development.

Maternal nutrition is critical in mammalian development, influencing the epigenetic reprogramming of gametes, embryos, and fetal programming. We evaluated the effects of different levels of sulfur (S) and cobalt (Co) in the maternal diet throughout the pre- and periconceptional periods on the biochemical and reproductive parameters of the donors and the DNA methylome of the progeny in Bos indicus cattle. The low-S/Co group differed from the control with respect to homocysteine, folic acid, B12, insulin growth factor 1, and glucose. The oocyte yield was lower in heifers from the low S/Co group than that in the control heifers. Embryos from the low-S/Co group exhibited 2320 differentially methylated regions (DMRs) across the genome compared with the control embryos. We also characterized candidate DMRs linked to the DNMT1 and DNMT3B genes in the blood and sperm cells of the adult progeny. A DMR located in DNMT1 that was identified in embryos remained differentially methylated in the sperm of the progeny from the low-S/Co group. Therefore, we associated changes in specific compounds in the maternal diet with DNA methylation modifications in the progeny. Our results help to elucidate the impact of maternal nutrition on epigenetic reprogramming in livestock, opening new avenues of research to study the effect of disturbed epigenetic patterns in early life on health and fertility in adulthood. Considering that cattle are physiologically similar to humans with respect to gestational length, our study may serve as a model for studies related to the developmental origin of health and disease in humans.

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This study aimed to evaluate the effect of scriptaid during pre-maturation (PIVM) and/or maturation (IVM) on developmental competence of bovine oocytes. Cumulus-oocyte complexes (COCs) were submitted to PIVM for 6 h in the presence or absence of scriptaid. COCs were distributed into five groups: T1-IVM for 22 h, T2-PIVM for 6 h and IVM for 22 h, T3-PIVM with scriptaid for 6 h and IVM for 22 h, T4-PIVM for 6 h and IVM with scriptaid for 22 h, and T5-PIVM with scriptaid for 6 h and IVM with scriptaid for 22 h. Nuclear maturation, gene expression, cumulus cells (CCs) expansion, and embryo development and quality were evaluated. At the end of maturation, all groups presented the majority of oocytes in MII (P>0.05). Only HAT1 gene was differentially expressed (P<0.01) in oocytes with different treatments. Regarding embryo development at D7, T4 (23%) and T5 (18%) had lower blastocyst rate (P<0.05) than the other treatments (T1 = 35%, T2 = 37% and T3 = 32%). No effect was observed when scriptaid in PIVM was used in less competent oocytes (P>0.05). In conclusion, presence of scriptaid in PIVM and/or IVM did not improve developmental competence or embryo quality.

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Dedico este trabalho a toda a minha família, em especial meu PAI Lincoln, que mesmo não estando presente fisicamente neste dia tão importante, tenho certeza que está muito orgulhoso por mais essa conquista, pois sempre colocou os estudos dos filhos em primeiro lugar.Obrigada por tudo PAI, SAUDADE SEMPRE... AGRADECIMENTOSA Deus, pela saúde e pelas oportunidades. Por sempre me iluminar e abençoar. À minha "MÃEPAI" MARINA, aos meus irmãos Marilin e Thiago e meu cunhado Luiz Maurício, por sempre terem me apoiado e dado força nos meus sonhos. Obrigada por todo o incentivo, ajuda e compreensão. Aos meus amigos e familiares que sempre compreenderam meus momentos de ausência. Ao meu orientador, Dr. Maurício Machaim Franco, pela oportunidade, confiança e ensinamentos. Muito Obrigada! À minha co-orientadora Dra. Margot Alves Nunes Dode, pela oportunidade dada, pelos ensinamentos diários, pela paciência, pelos incentivos, pela amizade e pela confiança. MUITO OBRIGADA POR TUDO! Aos "Tabajaras" mais queridos, Allice e Thiago, pela amizade e ajuda dada por esses anos. AMO!! À Andrielle, pela amizade, companhia nos momentos difíceis, e parceria nas horas boas também! À Ligiane e Ana Luiza, por toda ajuda e ensinamentos dentro do laboratório, Muito Obrigada!! Aos meus amigos de laboratório, Aline, Rafa, Catherine Lara, Felippe Caixeta, José Carvalho, Regivaldo e Anacleyde. Obrigada por toda a ajuda, pela amizade diária e pelos momentos de distração.

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