Examinando por Autor "Figueroa, Jaime"
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Ítem Addressing viral and bacterial threats to salmon farming in Chile: historical contexts and perspectives for management and contro(Wiley-Blackwell, 2019-05) Figueroa, Jaime; Cárcamo, Juan; Yañez, Alejandro; Olavarria, Victor; Ruiz, Pamela; Manríquez, René; Muñoz, Claudio; Avendaño-Herrera, Ruben; Romero, AlexThe rapid growth of the salmon farming industry in Chile has led to the appearance of various viral, bacterial, parasitic, and fungal pathogens affecting farmed fish. The Chilean salmon industry has suffered several health crises associated with high fish mortalities, such as caused by the infectious salmon anaemia virus (2007) and harmful algal blooms (2016). In addition to these events, marine farms are continuously affected by outbreaks of harmful pathogens, including the bacteria Piscirickettsia salmonis and, most recently, a reappearance of Renibacterium salmoninarum, and the infectious pancreatic necrosis virus. These outbreaks have led to stricter regulations, but the salmon farming industry continues to struggle despite reforms. In addition to the aforementioned pathogens, which are a continuous threat, other apparently under control pathogens have also reappeared in recent years. In this review, we analyse the current state of knowledge on four of the main pathogens affecting salmon farming in Chile. The infectious pancreatic necrosis virus is relevant as it affects freshwater-stage fish, with survivors then acting as carriers. The infectious salmon anaemia virus currently appears to be under control; however, P. salmonis and R. salmoninarum continue to be the cause for high mortalities in the Chilean aquaculture industry. © 2019 The Authors. Reviews in Aquaculture Published by John Wiley & Sons Australia, LtdÍtem Aislamiento, caracterización y expresión del factor de crecimiento tipo insulina I (igf-1) y el receptor de la hormona del crecimiento (ghr) del lenguado chileno (Paralichthys adspersus) : efecto de la restricción nutricional y el crecimiento compensatorio(Universidad Andrés Bello, 2007) Fuentes Jofré, Eduardo Nicolás; Molina Sirguiado, Alfredo Iván; Figueroa, Jaime; Reyes, Ariel; Facultad de Ecología y Recursos Naturales; Escuela de Ciencias del MarSe aisló y caracterizó el cDNA de igf-I y ghr de lenguado chileno (Paralichthys adspersus). Ambos genes muestran características comunes presentes en sus parálogos de otras especies de peces. Asimísmo se evaluó su expresión y la del inhibidor del crecimiento muscular miostatina en distintos tejidos, encontrándose expresión en todos los tejidos estudiados. Adicionalmente, se estudió el patrón de expresión de igf-I y ghr en estadios larvales, observándose una expresión dinámica en ambos genes. Se evaluó la influencia de la restricción nutricional y realimentación sobre la expresión de los mRNAs de igf-I y ghr por PCR en tiempo real. Los niveles del mRNA de ghr en el músculo se incrementaron durante el periodo de hambruna, mientras que durante la realimentación decrecieron. Un patrón de expresión opuesto fue encontrado para igf-I. En base a los resultados obtenidos se concluye que la expresión de genes involucrados en crecimiento puede ser utilizada como herramienta para evaluar el estado nutricional de peces de importancia comercialÍtem Discovery and Characterization of the ddx41 Gene in Atlantic Salmon: Evolutionary Implications, Structural Functions, and Innate Immune Responses to Piscirickettsia salmonis and Renibacterium salmoninarum Infections(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Yañez, Alejandro J.; Barrientos, Claudia A.; Isla, Adolfo; Aguilar, Marcelo; Flores-Martin, Sandra N.; Yuivar, Yassef; Ojeda, Adriana; Ibieta, Pablo; Hernández, Mauricio; Figueroa, Jaime; Avendaño-Herrera, Rubén; Mancilla, MarcosThe innate immune response in Salmo salar, mediated by pattern recognition receptors (PRRs), is crucial for defending against pathogens. This study examined DDX41 protein functions as a cytosolic/nuclear sensor for cyclic dinucleotides, RNA, and DNA from invasive intracellular bacteria. The investigation determined the existence, conservation, and functional expression of the ddx41 gene in S. salar. In silico predictions and experimental validations identified a single ddx41 gene on chromosome 5 in S. salar, showing 83.92% homology with its human counterpart. Transcriptomic analysis in salmon head kidney confirmed gene transcriptional integrity. Proteomic identification through mass spectrometry characterized three unique peptides with 99.99% statistical confidence. Phylogenetic analysis demonstrated significant evolutionary conservation across species. Functional gene expression analysis in SHK-1 cells infected by Piscirickettsia salmonis and Renibacterium salmoninarum indicated significant upregulation of DDX41, correlated with increased proinflammatory cytokine levels and activation of irf3 and interferon signaling pathways. In vivo studies corroborated DDX41 activation in immune responses, particularly when S. salar was challenged with P. salmonis, underscoring its potential in enhancing disease resistance. This is the first study to identify the DDX41 pathway as a key component in S. salar innate immune response to invading pathogens, establishing a basis for future research in salmonid disease resistance.Ítem Protein-Based Vaccine Protect Against Piscirickettsia salmonis in Atlantic Salmon (Salmo salar)(Frontiers Media S.A., 2021-02) Pontigo, Juan Pablo; Espinoza, Carla; Hernandez, Mauricio; Nourdin, Guillermo; Oliver, Cristian; Avendaño Herrera, Rubén; Figueroa, Jaime; Rauch, Cecilia; Troncoso, José M.; Vargas Chacoff, Luis; Yáñez, Alejandro J.An effective and economical vaccine against the Piscirickettsia salmonis pathogen is needed for sustainable salmon farming and to reduce disease-related economic losses. Consequently, the aquaculture industry urgently needs to investigate efficient prophylactic measures. Three protein-based vaccine prototypes against Piscirickettsia salmonis were prepared from a highly pathogenic Chilean isolate. Only one vaccine effectively protected Atlantic salmon (Salmo salar), in correlation with the induction of Piscirickettsia-specific IgM antibodies and a high induction of transcripts encoding pro-inflammatory cytokines (i.e., Il-1β and TNF-α). In addition, we studied the proteome fraction protein of P. salmonis strain Austral-005 using multidimensional protein identification technology. The analyzes identified 87 proteins of different subcellular origins, such as the cytoplasmic and membrane compartment, where many of them have virulence functions. The other two prototypes activated only the innate immune responses, but did not protect Salmo salar against P. salmonis. These results suggest that the knowledge of the formulation of vaccines based on P. salmonis proteins is useful as an effective therapy, this demonstrates the importance of the different research tools to improve the study of the different immune responses, resistance to diseases in the Atlantic salmon. We suggest that this vaccine can help prevent widespread infection by P. salmonis, in addition to being able to be used as a booster after a primary vaccine to maintain high levels of circulating protective antibodies, greatly helping to reduce the economic losses caused by the pathogen. © Copyright © 2021 Pontigo, Espinoza, Hernandez, Nourdin, Oliver, Avendaño-Herrera, Figueroa, Rauch, Troncoso, Vargas-Chacoff and Yáñez.