Evaluation of different culture systems on the in vitro production of bovine embryos.

The objective of this study was to determine the development potential and quality of in vitro produced bovine embryos cultured individually or in groups. After IVM and IVF, presumptive zygotes were cultured in groups or individually, either in drops or in the modified well of the well (mWOW) system. In Experiment 1, four culture systems were utilized: T1: drop in group (control); T2: mWOW in groups; T3: mWOW individually; and T4: drop individually. Cleavage and blastocyst rates at Days 6, 7 and 8 and total cell number of Day 6 blastocysts were similar (P > 0.05) for all treatments. However, in Day 7 blastocysts, total cell number was lower (P 0.05) for all treatments in the control group. For the vitrified embryos, lower hatching rates (P < 0.05) were observed in the T3 group. In conclusion, embryos cultured in groups in the mWOW system had the same blastocyst rates but better quality (measured by their survival after vitrification) than those cultured individually in the mWOW system

Blastocoel collapse associated with melatonin in the culture media improves bovine embryo viability after vitrification.

Publicado em Animal Reproduction, v. 13, n. 3, p. 699, jul./set. 2016

Post-hatching development of bovine embryos in vitro: the effects of tunnel preparation and gender.

The objective of this study was to compare morphological characteristics, kinetics of development, and gene expression ofmale and female IVP embryos thatwere cultured until day (D)15 (fertilization = D0), using either phosphate-buffered saline (PBS) or Milli-Q water (MQW) to dilute the agarose gel used for tunnel construction. On D11, embryos (n = 286) were placed in agarose gel tunnels diluted in PBS and MQW. Embryos were evaluated for morphology, and embryo size was recorded on D11, D12.5, D14 and D15. Then, embryos were sexed and used for gene expression analyses (G6PD, GLUT1, GLUT3, PGK1, PLAC8, KRT8, HSF1 and IFNT). The percentage of elongated embryos at D15 was higher (p < 0.05) in the PBS (54%) than in theMQW(42%) gel. However, embryos produced inMQWwere bigger (p < 0.05) and had a lower expression of GLUT1 (p = 0.08) than those cultured in PBS. There was a higher proportion of male than female embryos at D15 in both treatments, MQW(65% vs. 35%; p < 0.05) and PBS (67% vs. 33%; p < 0.05); however, embryo size was not signi?cantly different between genders. Moreover, D15 female embryos had greater expression of G6PD (p = 0.05) and KRT8 (p = 0.03) than male embryos. In conclusion, the diluent used for tunnel construction affected embryo development in the post-hatching development (PHD) system, and the use ofMQWwas the most indicative measure for the evaluation of embryo quality. Male and female embryos cultured from D11 to D15, either in an MQW or PBS agarose gel, demonstrated similar development but different gene expression

Transcritos quiméricos em bovinos.

Trans-splicing é um fenômeno no qual exons dos transcritos primários de genes distintos se unem para formar um novo e único transcrito quimérico, sendo comum em nematóides e kinetoplastideos, mas raro em organismos superiores. Embora não seja tão bem compreendido quanto o cis-splicing, o trans-splicing tem despertado interesse devido às suas possíveis aplicações biotecnológicas, principalmente aquelas envolvendo regulação da expressão gênica ou formação de novas proteínas. Recentemente, desenvolvemos uma metodologia de Bioinformática para a detecção de transcritos quiméricos em bases de FlcDNA (Herai & Yamagishi, 2010a), e estendemos essa metodologia para organismos cujo genoma não tenha uma alta qualidade de montagem (Herai & Yamagishi, 2010b). Como prova de conceito, aplicamos essa metodologia ao genoma do Bos taurus UMD 3.0 e identificamos 13 transcritos quiméricos candidatos a trans-splicing. O foco da pesquisa é a confirmação biológica do trans-splicing em bovinos, particularmente, nas fases embrionária e fetal onde, a formação de transcritos quiméricos pode ter função biológica importante. Se confirmados, esses seriam os primeiros casos biologicamente comprovados de trans-splicing em bovinos, pois o único caso até agora reportado (Roux et al., 2006) envolve dois genes muito próximos, o que pode ser interpretado como um caso de splicing alternativo, ao invés de trans-splicing.Pôster 77

Study on nuclear maturation kinetics of bovine ovocyts with different degrees of competence.

Proceedings of the 31st Annual Meeting of the Brazilian Embryo Technology Society (SBTE); Cabo de Santo Agostinho, PE, Brazil, August 17th to 19th, 2017. Abstract