IIBIO   27936
INSTITUTO DE INVESTIGACIONES BIOTECNOLOGICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
2 Role of histone H3 lysine 9 trimethylation during bovine pre-implantation embryonic development
Autor/es:
BLUGÜERMANN CAROLINA; OSYCKA CLAUDIA; VON MEYEREN MICAELA; MUTTO ADRIAN ANGEL; NAVARRO MICAELA; BARIANI VICTORIA
Lugar:
New Orleans
Reunión:
Congreso; 45th Annual Conference of the IETS (International Embryo Technology Society); 2019
Resumen:
Histones play an important role in DNA?s compaction and organisation into the cellular nucleus. Depending on which histone modification occurs, chromatin can take a conformation of heterochromatin or euchromatin, which are associated with gene repression or expression, respectively. Histone H3 lysine 9 (H3K9) trimethylation (H3K9me3) is associated with gene silencing. At least 3 methyltransferases are able to change the methylation status of H3K9: SUV39H1, SUV39H2, and SETDB1. In several mammalian species, modulation of H3K9 methylation status has been demonstrated to be necessary to achieve a successful pre-implantation embryonic development after IVF or somatic cell NT. The aim of this work was to study the role of H3K9me3 in IVF pre-implantation bovine embryos. For this purpose, immunostaining of H3K9me3 at different pre-implantation stages of development was performed. Further, the relative abundances of the methyltransferases SUV39H1 and SUV39H2 were measured by real-time PCR using luciferase transcript as an exogenous gene for normalization. Finally, to evaluate H3K9me3 involvement during pre-implantation embryonic development, we generated SUV39H1 or SUV39H2 knockout embryos by the CRISPR/Cas9 system. We designed guide RNA targeting SUV39H1 or SUV39H2 and co-injected the presumptive zygote?s cytoplasm 18 h post-fertilization with Cas9 protein. At Day 8 post-fertilization, the number of blastocysts was assessed and embryos were immunostained to evaluate H3K9me3. Results were analysed using Student?s t-test or ANOVA with the post-hoc Tukey test depending on data set (P ≤ 0.05) and reported as means ± standard errors of the mean. Oocytes at germinal vesicle stage and metaphase II as well as embryos at different stages of pre-implantation development (2, 4, and 8 cells, morula, and blastocyst; n = 6) were immunoreactive for H3K9me3. Expression of SUV39H1 and SUV39H2 mRNA decreased significantly as embryonic development progressed, reaching undetectable levels at stages where genome activation had already occurred (morula and blastocyst; P