441 research outputs found

    Searching for the roots of the first free African American community

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    San Basilio de Palenque is an Afro-descendant community near Cartagena, Colombia, founded in the sixteenth century. The recognition of the historical and cultural importance of Palenque has promoted several studies, namely concerning the African roots of its first inhabitants. To deepen the knowledge of the origin and diversity of the Palenque parental lineages, we analysed a sample of 81 individuals for the entire mtDNA Control Region as well as 92 individuals for 27 Y-STRs and 95 for 51 Y-SNPs. The results confirmed the strong isolation of the Palenque, with some degree of influx of Native American maternal lineages, and a European admixture exclusively mediated by men. Due to the high genetic drift observed, a pairwise FST analysis with available data on African populations proved to be inadequate for determining population affinities. In contrast, when a phylogenetic approach was used, it was possible to infer the phylogeographic origin of some lineages in Palenque. Contradicting previous studies indicating a single African origin, our results evidence parental genetic contributions from widely different African regions.We thank all sample donors for their contribution to this work and all the people who helped with sample collection, namely, Regina Miranda from the Community of San Basilio de Palenque, the personnel of the Benkos Biojó Rural school, and Miguel Obeso from the etnoeducación program. This work was supported by the University of Cartagena and FPIT—Fundación para la promoción de la investigación y la tecnología del Banco de la República, Colombia (FPIT-388) and partially financed by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020—Operacional Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through FCT—Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Inovação in the framework of the projects “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274). FS was supported by Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro—FAPERJ (E-26/202.275/2019). LG was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico—CNPq (ref. 306342/2019-7), and Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro—FAPERJ (CNE-2018). VG was supported by FCT, under the program contract provided in Decree-Law no.57/2016 of August 29. The IPATIMUP integrates the i3S research unit, which is partially supported by the Portuguese Foundation for Science and Technology

    Amphibians on the hotspot: Molecular biology and conservation in the South American Atlantic Rainforest

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    Amphibians are the focus of a recent debate and public attention owing to the global decline in their populations worldwide. Amphibians are one of the most threatened and poorly known groups of vertebrates in several geographic areas, even though they play a central role in their own ecosystems. At different levels, amphibians make their contribution to proper ecosystem functioning. They act as regulators of the food web and nutrient cycling, and they also provide several valuable ecosystem services, e.g., as a food source and as animal models for lab research. In this sense, it seems clear that the maintenance of amphibian diversity should be one of the major goals for the several countries where their population decline is observed. However, we are still struggling with the very first step of this process, i.e., the correct identification of the amphibian species diversity. Over the past few decades, research on molecular identification of amphibians using DNA barcoding has encountered some difficulties related to high variability in the mitochondrial genome of amphibians, and a research gap is noticeable in the literature. We herein evaluated both COI and 16S rRNA mitochondrial genes for the molecular identification of frogs and tadpoles in a large fragment of the South American Atlantic Rainforest in Rio de Janeiro, Brazil. Our results suggest that both COI and 16S rRNA are informative markers for the molecular identification of the amphibian specimens with all specimens unambiguously identified at the species level. We also made publicly available 12 new sequences of Atlantic Rainforest amphibian species for the first time, and we discussed some conservation issues related to amphibians within the Atlantic Rainforest domains in the state of Rio de Janeiro, Brazil.The authors benefited from grants provided to CFDR (304791/2010-5; 470265/2010- 8 and 302974/2015-6) from Conselho Nacional do Desenvolvimento Cientifico e Tecnologico (CNPq) and through "Cientistas do Nosso Estado" Program from FAPERJ to CFDR (process No. E-26/ 102.765.2012 E-26/202.920.2015). We would like to thank C. Haddad (Universidade Estadual Paulista) and M. L. Lyra (Universidade Estadual Paulista) for some of the specimens and the primers used in the present manuscript and L. A. Fusinatto, who kindly revised the manuscript offering helpful suggestions. FP was supported by the Portuguese Foundation for Science and Technology (FCT) [IF/01356/2012] and Northern Regional Operational Programme (NORTE2020) through the European Regional Development Fund (ERDF) [MARINFO NORTE-01-0145-FEDER- 000031]. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Overexpression of circulating MiR-30b-5p identifies advanced breast cancer

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    Breast cancer (BrC) remains the leading cause of cancer-related death in women, mainly due to recurrent and/or metastatic events, entailing the need for biomarkers predictive of progression to advanced disease. MicroRNAs hold promise as noninvasive cancer biomarkers due to their inherent stability and resilience in tissues and bodily fluids. There is increasing evidence that specific microRNAs play a functional role at different steps of the metastatic cascade, behaving as signaling mediators to enable the colonization of a specific organ. Herein, we aimed to evaluate the biomarker performance of microRNAs previously reported as associated with prognosis for predicting BrC progression in liquid biopsies. Background Breast cancer (BrC) remains the leading cause of cancer-related death in women, mainly due to recurrent and/or metastatic events, entailing the need for biomarkers predictive of progression to advanced disease. MicroRNAs hold promise as noninvasive cancer biomarkers due to their inherent stability and resilience in tissues and bodily fluids. There is increasing evidence that specific microRNAs play a functional role at different steps of the metastatic cascade, behaving as signaling mediators to enable the colonization of a specific organ. Herein, we aimed to evaluate the biomarker performance of microRNAs previously reported as associated with prognosis for predicting BrC progression in liquid biopsies. Methods Selected microRNAs were assessed using a quantitative reverse transcription-polymerase chain reaction in a testing cohort of formalin-fixed paraffin-embedded primary (n = 16) and metastatic BrC tissues (n = 22). Then, miR-30b-5p and miR-200b-3p were assessed in a validation cohort #1 of formalin-fixed paraffin-embedded primary (n = 82) and metastatic BrC tissues (n = 93), whereas only miR-30b-5p was validated on a validation cohort #2 of liquid biopsies from BrC patients with localized (n = 20) and advanced (n = 25) disease. ROC curve was constructed to evaluate prognostic performance. Results MiR-30b-5p was differentially expressed in primary tumors and paired metastatic lesions, with bone metastases displaying significantly higher miR-30b-5p expression levels, paralleling the corresponding primary tumors. Interestingly, patients with advanced disease disclosed increased circulating miR-30b-5p expression compared to patients with localized BrC. Conclusions MiR-30b-5p might identify BrC patients at higher risk of disease progression, thus, providing a useful clinical tool for patients’ monitoring, entailing earlier and more effective treatment. Nonetheless, validation in larger multicentric cohorts is mandatory to confirm these findings.Research Center of Portuguese Oncology Institute of Porto (PI 74-CI-IPOP-19-2016). JL and CSG are supported by a PhD fellowship from FCT - Fundação para a Ciência e Tecnologia (SFRH/ BD/132751/2017 and SFRH/BD/92786/2013, respectively). SS is supported by a PhD fellowship IPO/ESTIMA-1 NORTE-01-0145-FEDER-000027. BMC is funded by FCT-Fundação para a Ciência e a Tecnologia (IF/00601/2012
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