Genetic diversity and structure of the commercially important native fish pacu (Piaractus mesopotamicus) from cultured and wild fish populations: relevance for broodstock management

Pacu (Piaractus mesopotamicus) is one of the most important Neotropical freshwater fish species produced by aquaculture in South America. This study is the first attempt to inquire about aquaculture stocks in Argentina regarding genetic diversity and structure. Neither genetic characterization nor pedigree records are available for pacu stocks in farms in Argentina. The presence of hybrids in both natural environment (Lower Paraná River) and farms has not been evaluated yet at the southern region of pacu distribution. Genetic characterization of pacu broodstocks, corresponding to 8 farms, and wild individuals from four areas at Lower Paraná River was performed. Pacu hybrids were not detected neither in wild nor in farm stocks analyzed. In general, similar levels of genetic diversity were observed between cultured and wild fish populations. Global genetic differentiation (Fst = 0.055) indicated a low level of structure and AMOVA showed that genetic variation was mostly within populations. Reduced contemporary effective population size (Ne) was observed, and probably reflects the bottleneck by founder effect in farmed fish populations. Moreover, kinship analysis showed that in fish farms, on average, 43.00% of the individuals were genetically related, whereas in wild population it was 36.40%. We recommend that broodstock management practices, such as using large Ne, single pair mating, precise records, and tagging of brood fish, should be implemented to avoid unintentional mismanagement.Fil: Del Pazo, F.. Universidad Nacional de Rosario; ArgentinaFil: Sánchez, Sebastián. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias. Instituto de Ictiología del Nordeste; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Posner, Victoria. Universidad Nacional de Rosario; ArgentinaFil: Sciara, Andrés A.. Universidad Nacional de Rosario; ArgentinaFil: Arranz, Silvia Eda. Universidad Nacional de Rosario; ArgentinaFil: Villanova, Gabriela V.. Universidad Nacional de Rosario; Argentin

Improving zebrafish embryo xenotransplantation conditions by increasing incubation temperature and establishing a proliferation index with ZFtool

Background Zebrafish (Danio rerio) is a model organism that has emerged as a tool for cancer research, cancer being the second most common cause of death after cardiovascular disease for humans in the developed world. Zebrafish is a useful model for xenotransplantation of human cancer cells and toxicity studies of different chemotherapeutic compounds in vivo. Compared to the murine model, the zebrafish model is faster, can be screened using high-throughput methods and has a lower maintenance cost, making it possible and affordable to create personalized therapies. While several methods for cell proliferation determination based on image acquisition and quantification have been developed, some drawbacks still remain. In the xenotransplantation technique, quantification of cellular proliferation in vivo is critical to standardize the process for future preclinical applications of the model. Methods This study improved the conditions of the xenotransplantation technique – quantification of cellular proliferation in vivo was performed through image processing with our ZFtool software and optimization of temperature in order to standardize the process for a future preclinical applications. ZFtool was developed to establish a base threshold that eliminates embryo auto-fluorescence and measures the area of marked cells (GFP) and the intensity of those cells to define a ‘proliferation index’. Results The analysis of tumor cell proliferation at different temperatures (34 °C and 36 °C) in comparison to in vitro cell proliferation provides of a better proliferation rate, achieved as expected at 36°, a maintenance temperature not demonstrated up to now. The mortality of the embryos remained between 5% and 15%. 5- Fluorouracil was tested for 2 days, dissolved in the incubation medium, in order to quantify the reduction of the tumor mass injected. In almost all of the embryos incubated at 36 °C and incubated with 5-Fluorouracil, there was a significant tumor cell reduction compared with the control group. This was not the case at 34 °C. Conclusions Our results demonstrate that the proliferation of the injected cells is better at 36 °C and that this temperature is the most suitable for testing chemotherapeutic drugs like the 5-FluorouracilThis research was funded by the Fondo de Investigación Sanitaria (Instituto Carlos III) - FIS project (PI13/01388). The funding body had no role in the design of the study and collection, analysis, and interpretation of data and in writing of this manuscriptS

Improving zebrafish embryo xenotransplantation conditions by increasing incubation temperature and establishing a proliferation index with ZFtool

Abstract Background Zebrafish (Danio rerio) is a model organism that has emerged as a tool for cancer research, cancer being the second most common cause of death after cardiovascular disease for humans in the developed world. Zebrafish is a useful model for xenotransplantation of human cancer cells and toxicity studies of different chemotherapeutic compounds in vivo. Compared to the murine model, the zebrafish model is faster, can be screened using high-throughput methods and has a lower maintenance cost, making it possible and affordable to create personalized therapies. While several methods for cell proliferation determination based on image acquisition and quantification have been developed, some drawbacks still remain. In the xenotransplantation technique, quantification of cellular proliferation in vivo is critical to standardize the process for future preclinical applications of the model. Methods This study improved the conditions of the xenotransplantation technique – quantification of cellular proliferation in vivo was performed through image processing with our ZFtool software and optimization of temperature in order to standardize the process for a future preclinical applications. ZFtool was developed to establish a base threshold that eliminates embryo auto-fluorescence and measures the area of marked cells (GFP) and the intensity of those cells to define a ‘proliferation index’. Results The analysis of tumor cell proliferation at different temperatures (34 °C and 36 °C) in comparison to in vitro cell proliferation provides of a better proliferation rate, achieved as expected at 36°, a maintenance temperature not demonstrated up to now. The mortality of the embryos remained between 5% and 15%. 5- Fluorouracil was tested for 2 days, dissolved in the incubation medium, in order to quantify the reduction of the tumor mass injected. In almost all of the embryos incubated at 36 °C and incubated with 5-Fluorouracil, there was a significant tumor cell reduction compared with the control group. This was not the case at 34 °C. Conclusions Our results demonstrate that the proliferation of the injected cells is better at 36 °C and that this temperature is the most suitable for testing chemotherapeutic drugs like the 5-Fluorouracil

Administración Pública y Sociedad (ApyS). Núm. 16, 2009

La Revista Administración Pública y Sociedad (APyS) es una publicación del Instituto de Investigación y Formación en Administración Pública (IIFAP), unidad académica perteneciente a la Facultad de Ciencias Sociales de la Universidad Nacional de Córdoba (UNC).publishedVersio