HDAC inhibition decreases XIST expression on female IVP bovine blastocysts

During initial development, both X chromosomes are active in females, and one of them must be silenced at the appropriate time in order to dosage compensate their gene expression levels to male counterparts. Silencing involves epigenetic mechanisms, including histone deacetylation. Major X chromosome inactivation (XCI) in bovine occurs between hatching and implantation, although in vitro culture conditions might disrupt the silencing process, increasing or decreasing X-linked gene expression. In this study, we aimed to address the roles of histone deacetylase inhibition by trichostatin A (TSA) on female preimplantation development.We tested the hypothesis that by enhancing histone acetylation, TSA would increase the percentage of embryos achieving 16-cell stage, reducing percentage of embryos blocked at 8-cell stage, and interfere with XCI in IVF embryos. We noticed that after TSA treatment, acetylation levels in individual blastomeres of 8-16 cell embryos were increased twofold on treated embryos, and the samewas detected for blastocysts. Changes among blastomere levels within the same embryo were diminished on TSA group, as low-acetylated blastomeres were no longer detected. The percentage of embryos that reached the 5th cleavage cycle 118 h after IVF, analyzed by Hoechst staining, remained unaltered after TSA treatment. Then, we assessed XIST and G6PD expression in individual female bovine blastocysts by quantitative real-time PCR. Even though G6PD expression remained unaltered after TSA exposure, XIST expression was eightfold decreased, and we also detected a major decrease in the percentage of blastocysts expressing detectable XIST levels after TSA treatment. Based on these results, we conclude that HDAC is involved on XCI process in bovine embryos, and its inhibition might delay X chromosome silencing and attenuate aberrant XIST expression described for IVF embryos. © 2013 Society for Reproduction and Fertility.

Bone morphogenetic protein 15 and fibroblast growth factor 10 enhance cumulus expansion, glucose uptake, and expression of genes in the ovulatory cascade during in vitro maturation of bovine cumulus-oocyte complexes

Oocyte-secreted factors (OSFs) regulate differentiation of cumulus cells and are of pivotal relevance for fertility. Bone morphogenetic protein 15 (BMP15) and fibroblast growth factor 10 (FGF10) are OSFs and enhance oocyte competence by unknown mechanisms. We tested the hypothesis that BMP15 and FGF10, alone or combined in the maturation medium, enhance cumulus expansion and expression of genes in the preovulatory cascade and regulate glucose metabolism favouring hyaluronic acid production in bovine cumulus-oocyte complexes (COCs). BMP15 or FGF10 increased the percentage of fully expanded COCs, but the combination did not further stimulate it. BMP15 increased cumulus cell levels of mRNA encoding a disintegrin and metalloprotease 10 (ADAM10), ADAM17, amphiregulin (AREG), and epiregulin (EREG) at 12 h of culture and of prostaglandin (PG)-endoperoxide synthase 2 (PTGS2), pentraxin 3 (PTX3) and tumor necrosis factor alpha-induced protein 6 (TNFAIP6 (TSG6)) at 22 h of culture. FGF10 did not alter the expression of epidermal growth factor-like factors but enhanced the mRNA expression of PTGS2 at 4 h, PTX3 at 12 h, and TNFAIP6 at 22 h. FGF10 and BMP15 stimulated glucose consumption by cumulus cells but did not affect lactate production or levels of mRNA encoding glycolytic enzymes phosphofructokinase and lactate dehydrogenase A. Each growth factor increased mRNA encoding glucosamine:fructose-6-PO4 transaminases, key enzymes in the hexosamine pathway leading to hyaluronic acid production, and BMP15 also stimulated hyaluronan synthase 2 (HAS2) mRNA expression. This study provides evidence that BMP15 and FGF10 stimulate expansion of in vitro-matured bovine COCs by driving glucose metabolism toward hyaluronic acid production and controlling the expression of genes in the ovulatory cascade, the first acting upon ADAM10, ADAM17, AREG, and EREG and the second on downstream genes, particularly PTGS2. © 2013 Society for Reproduction and Fertility.

Efeitos do treinamento resistido concêntrico e excêntrico sobre a modulação autonômica cardíaca e parâmetros cardiovasculares

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise do gasto energético e composição corporal de adolescentes obesos sedentários e de adolescentes obesos submetidos a treinamento concorrente

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aplicação do modelo de potência crítica na cinética do consumo de oxigênio em exercício supramáximo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos das doses subletais de fipronil para abelhas africanizadas (Apis mellifera L.), por meio de análises morfológicas e comportamentais

Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC

Caracterização genotípica microrganismos isolados de infecções da corrente sanguína relacionadas a cateteres em recém-nascidos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da agressividade e caracterização genética de linhagens de Ralstonia Solanacearum isoladas de diferentes plantas hospedeiras

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da infecção de ratos Fischer com dua amostras geneticamente distintas de Toxoplasma gondii: cinética de anticorpos, reisolamento em camundongos e reação em cadeia pela polimerase

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Parâmetros genéticos para produção de leite e persistência de lactações múltiplas na raça Gir

Pós-graduação em Genética e Melhoramento Animal - FCAV

Estudo epidemiológico do gênero Aeromonas, por meio de técnicas moleculares, em diversas etapas do abate bovino

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Reação de genótipos de feijoeiro a Curtobacterium flaccumfaciens PV. flaccumfaciens, agressividade e variabilidade molecular de isolados

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Diversidade genética, fatores de virulência e perfis de susceptibilidade a antimicrobianos de isolados de Escherichia coli provenientes do útero, da boca e das fezes de cadelas com piometra

Pós-graduação em Microbiologia Agropecuária - FCAV

Representação e armazenamento de dados cadastrais 3D em banco de dados geográficos

Pós-graduação em Ciências Cartográficas - FCT

Influence of agrochemicals fipronil and imidacloprid on the learning behavior of Apis mellifera L. honeybees

Agrochemicals on crop cultivated areas is a source of contamination for bees and may cause physiological and behavioral disorders and mortality. The LD50 of the pesticides fipronil and imidacloprid was determined and their effect on the learning behavior of Apis mellifera L. honeybee evaluated. LD50 was determined by the ingestion of contaminated food with different concentrations of insecticide concentrations: Fipronil (0, 0.8, 0.4, 0.2, 0.1 and 0.05 µg bee-1) and imidacloprid (0, 0.4, 0.2, 0.1, 0.05 and 0.025 µg bee-1). The method of proboscis extension reflection (PER) and learning through citral odor evaluated their responses to food stimulation. LD50 obtained were 0.28 ± 0.11 and 0.10 ± 0.04 µg bee-1 for fipronil and imidacloprid, respectively. The PER test showed no significant difference (p < 0.05) although agrochemicals affected the learning of bees. Insecticides fipronil and imidacloprid are extremely harmful to foraging Africanized Apis mellifera bees.