Métodos de amostragem de solos em áreas sob plantio direto no Sudoeste Goiano.

Este trabalho teve por objetivo estudar as variações ocorridas nos resultados de análises químicas de solos cultivados em diferentes locais e períodos de adoção do sistema plantio direto na região de Rio Verde, GO

Cryotolerance and pregnancy rates after exposure of bovine in vitro-produced embryos to forskolin and linoleic acid before vitrification.

The objective of the present study was to evaluate the effects of supplementation of in vitro culture (IVC) medium with drugs that stimulates the lipolysis (Forskolin: Forsk) and inhibit the lipogenesis (Linoleic Acid LA) on the intracytoplasmic lipid content and cryotolerance of bovine embryos (Experiment 1), as well as to evaluate the effect of treatment of embryos with Forsk on the pregnancy rates after transfer to synchronized recipients (Experiment 2).Proceedings of the 30th Annual Meeting of the Brazilian Embryo Technology Society (SBTE); Foz do Iguaçu, PR, Brazil, August 25th to 27th, 2016, and 32nd Meeting of the European Embryo Transfer Association (AETE); Barcelona, Spain, September 9th and 10th, 2016. A327 Support Biotechnologies: Cryopreservation and cryobiology, diagnosis through imaging, molecular biology and ?omics?. Título em português: Criotolerância e taxa de concepção após exposição de embriões bovinos produzidos in vitro ao Forskolin ou ácido linoleico antes da vitrificação

Zinc supplementation during in vitro culture of bovine growing oocytes

Background: In cattle, early antral ovarian follicles (0.5-2 mm in diameter) typically contain growing oocytes. Most of these oocytes have filamentous chromatin within the germinal vesicle, are still transcriptionally active and have not yet acquired the meiotic competence, as demonstrated by the inability of resuming meiosis once isolated from the follicular compartment. Consequently, these oocytes cannot currently be used in standard protocols for in vitro embryo production (IVP) limiting the exploitation of the ovarian population for assisted reproduction purposes. Aims: In this view, aim of our studies is to improve the outcome of in vitro culture of growing oocytes (IVCO), in order to increase the amount of oocytes per ovary that can be used for embryo production. Method: By mining transcriptomic databases (http://emb-bioinfo.fsaa.ulaval.ca/IMAGE/) we observed that zinc (Zn) transporters are differentially expressed in different cell types throughout several steps of oogenesis in cattle. This observation, supported by studies in mice that revealed the importance of Zn in regulating oogenesis and early embryogenesis, seems to suggest the supplementation of culture medium with this element as a possible strategy. Hence we tested whether Zn might be beneficial to the acquisition of meiotic competence in bovine growing oocytes. Results: Zn supplementation during 24 hours of IVCO significantly improved the proportion of oocytes reaching the metaphase-II stage of meiosis after subsequent standard in vitro maturation compared to non-supplemented control. Furthermore the global transcriptional activity was significantly increased in growing oocytes cultured with Zn, while short time treatment with a Zn chelator (TPEN) had a negative effect on transcription. From a mechanistic point of view, these findings likely suggest that Zn support the synthesis of molecules needed for the successful completion of the subsequent steps of oogenesis in growing oocytes. Further studies are in progress to test the effect of Zn supplementation on embryo development of growing oocytes

Neonatal Fc Receptor Mediates Internalization of Fc in Transfected Human Endothelial Cells

The neonatal Fc receptor, FcRn mediates an endocytic salvage pathway that prevents degradation of IgG, thus contributing to the homeostasis of circulating IgG. Based on the low affinity of IgG for FcRn at neutral pH, internalization of IgG by endothelial cells is generally believed to occur via fluid-phase endocytosis. To investigate the role of FcRn in IgG internalization, we used quantitative confocal microscopy to characterize internalization of fluorescent Fc molecules by HULEC-5A lung microvascular endothelia transfected with GFP fusion proteins of human or mouse FcRn. In these studies, cells transfected with FcRn accumulated significantly more intracellular Fc than untransfected cells. Internalization of FcRn-binding forms of Fc was proportional to FcRn expression level, was enriched relative to dextran internalization in proportion to FcRn expression level, and was blocked by incubation with excess unlabeled Fc. Because we were unable to detect either surface expression of FcRn or surface binding of Fc, these results suggest that FcRn-dependent internalization of Fc may occur through sequestration of Fc by FcRn in early endosomes. These studies indicate that FcRn-dependent internalization of IgG may be important not only in cells taking up IgG from an extracellular acidic space, but also in endothelial cells participating in homeostatic regulation of circulating IgG levels