61 research outputs found

    Regulated mitochondrial DNA replication during oocyte maturation is essential for successful porcine embryonic development.

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    Cellular ATP is mainly generated through mitochondrial oxidative phosphorylation, which is dependent on mitochondrial DNA (mtDNA). We have previously demonstrated the importance of oocyte mtDNA for porcine and human fertilization. However, the role of nuclear-encoded mitochondrial replication factors during oocyte and embryo development is not yet understood. We have analyzed two key factors, mitochondrial transcription factor A (TFAM) and polymerase gamma (POLG), to determine their role in oocyte and early embryo development. Competent and incompetent oocytes, as determined by brilliant cresyl blue (BCB) dye, were assessed intermittently during the maturation process for TFAM and POLG mRNA using real-time RT-PCR, for TFAM and POLG protein using immunocytochemistry, and for mtDNA copy number using real-time PCR. Analysis was also carried out following treatment of maturing oocytes with the mtDNA replication inhibitor, 2',3'-dideoxycytidine (ddC). Following in vitro fertilization, preimplantation embryos were also analyzed. Despite increased levels of TFAM and POLG mRNA and protein at the four-cell stage, no increase in mtDNA copy number was observed in early preimplantation development. To compensate for this, mtDNA appeared to be replicated during oocyte maturation. However, significant differences in nuclear-encoded regulatory protein expression were observed between BCB(+) and BCB(-) oocytes and between untreated oocytes and those treated with ddC. These changes resulted in delayed mtDNA replication, which correlated to reduced fertilization and embryonic development. We therefore conclude that adherence to the regulation of the timing of mtDNA replication during oocyte maturation is essential for successful embryonic development

    Risks for human and animal health related to the presence of phorbol esters in Jatropha kernel meal

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    The Panel wishes to thank the members of the Working Group on Phorbol Esters: Bruce Cottrill, Stefano Dall'Acqua, Johanna Fink-Gremmels, Harinder P.S. Makkar and Manfred Metzler for the preparatory work on this scientific opinion, and EFSA staff: Marco Binaglia, Karen Mackay and Rositsa Serafimova for the support provided to this scientific opinion.Peer reviewedPublisher PD

    Presence of microplastics and nanoplastics in food, with particular focus on seafood

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    The Panel wishes to thank the members of the Working Group on the presence of microplastics and nanoplastics in food, with particular focus on seafood: Francesco Cubadda, Christer Hogstrand, Peter Hollman, Hendrik Van Loveren, Anne-Katrine Lundebye and Annette Petersen for the preparatory work on this statement, the hearing expert: Stephanie Wright and EFSA staff member: Karen Mackay for the support provided to this statement.Peer reviewedPublisher PD

    Assessment of an application on a detoxification process of groundnut press cake for aflatoxins by ammoniation

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    12 p.-2 fig.-2 tab.Following a request from the European Commission, the EFSA Panel on Contaminants in the Food Chain (CONTAM) provided a scientific opinion on an application for a detoxification process of groundnut press cake for aflatoxins by ammoniation. Specifically, it is required that the feed decontamination process is compliant with the acceptability criteria specified in the Commission Regulation (EU) 2015/786 of 19 May 2015. The CONTAM Panel assessed the data provided by the feed business operator with respect to the efficacy of the process to remove the contaminant from groundnut press cake batches and on information demonstrating that the process does not adversely affect the characteristics and the nature of the product. Although according to the literature the process may be able to reduce aflatoxin levels below the legal limits, the Panel concluded that the proposed decontamination process, on the basis of the experimental data submitted by the feed business operator, cannot be confirmed for compliance with the acceptability criteria provided for in Commission Regulation (EU) 2015/786 of 19 May 2015. The Panel recommended sufficient sample testing before and after the process, under the selected conditions, to ensure that the process is reproducible and reliable and to demonstrate that the detoxification is not reversible. In addition, genotoxicity testing of extracts of the treated feedingstuff and of the identified degradation products would be necessary. Finally, information on the transfer rate of AFB1 to AFM1 excretion in milk for animals fed the ammoniated product, in comparison to the starting material and on the ammoniation process changes of the nutritional values of the feed material should be provided.The Panel wishes to thank Federico Cruciani and Carina Wenger for the support provided to this scientific output, and the hearing expert Professor Dr Wayne L Bryden, for the overview on aflatoxin inactivation by ammoniation.Peer reviewe

    Update of the risk assessment of hexabromocyclododecanes (HBCDDs) in food

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    Panel members: Margherita Bignami, Laurent Bodin, James Kevin Chipman, Jesus del Mazo, BettinaGrasl-Kraupp, Christer Hogstrand, Laurentius (Ron) Hoogenboom, Jean-Charles Leblanc, Carlo StefanoNebbia, Elsa Nielsen, Evangelia Ntzani, Annette Petersen, Salomon Sand, Dieter Schrenk, TanjaSchwerdtle, Christiane Vleminckx and Heather Wallace Requestor: European Commission Question number: EFSA‐Q‐2018‐00433 Acknowledgements: The Panel wishes to thank the hearing experts: Cathy Fernandes and Henri Schroeder, and EFSA staff members: Kelly Niermans and Federico Cruciani, for the support provided to this scientific output. The Panel wishes to acknowledge all European competent institutions and Member State bodies that provided consumption and occurrence data for this scientific output. Data: All annexes on occurrence and exposure data, as well as the protocol used to produce this Scientific opinion, cross‐referenced in the text, are available on the EFSA Knowledge Junction at: https://doi.org/10.5281/zenodo.4475651Peer reviewedPublisher PD

    Risk assessment of chlorinated paraffins in feed and food

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    The Panel wishes to thank the hearing expert: Kerstin Krätschmer and EFSA staff member: Kelly Niermans for the support provided to this scientific output. The CONTAM Panel acknowledges all European competent institutions and other stakeholders that provided occurrence data in food and human milk and data on the toxicity of CPs, and supported the data collection for the Comprehensive European Food Consumption Database.Peer reviewedPublisher PD
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