Temperature effect on oxidative stress and egg quality-related genes on post-ovulatory eggs and ovary of red cusk-eel (Genypterus chilensis)

Red cusk-eel (Genypterus chilensis) is a native species with potential for Chilean aquaculture diversification. However, no information exists on the effects of temperature on oxidative stress and eggs quality markers in post-ovulatory eggs and ovary of this species. We determine that high and low temperature generate oxidative damage on post-ovulatory eggs, with no effect on ovary. Temperature induces thermal stress markers expression on post-ovulatory eggs, and modulates antioxidant and eggs quality markers on post-ovulatory eggs and ovary, information to consider for quality evaluation in the red cusk-eel management.

mRNA-seq reveals skeletal muscle atrophy in response to handling stress in a marine teleost, the red cusk-eel (Genypterus chilensis)

Background

Fish reared under intensive conditions are repeatedly exposed to stress, which negatively impacts growth. Although most fish follow a conserved pattern of stress response, with increased concentrations of cortisol, each species presents specificities in the cell response and stress tolerance. Therefore, culturing new species requires a detailed knowledge of these specific responses. The red cusk-eel (Genypterus chilensis) is a new economically important marine species for the Chilean aquaculture industry. However, there is no information on the stress- and cortisol-induced mechanisms that decrease skeletal muscle growth in this teleost.

Results

Using Illumina RNA-seq technology, skeletal muscle sequence reads for G. chilensis were generated under control and handling stress conditions. Reads were mapped onto a reference transcriptome, resulting in the in silico identification of 785 up-regulated and 167 down-regulated transcripts. Gene ontology enrichment analysis revealed a significant up-regulation of catabolic genes associated with skeletal muscle atrophy. These results were validated by RT-qPCR analysis for ten candidates genes involved in ubiquitin-mediated proteolysis, autophagy and skeletal muscle growth. Additionally, using a primary culture of fish skeletal muscle cells, the effect of cortisol was evaluated in relation to red cusk-eel skeletal muscle atrophy.

Conclusions

The present data demonstrated that handling stress promotes skeletal muscle atrophy in the marine teleost G. chilensis through the expression of components of the ubiquitin-proteasome and autophagy-lysosome systems. Furthermore, cortisol was a powerful inductor of skeletal muscle atrophy in fish myotubes. This study is an important step towards understanding the atrophy system in non-model teleost species and provides novel insights on the cellular and molecular mechanisms that control skeletal muscle growth in early vertebrates.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-2232-7) contains supplementary material, which is available to authorized users.

Isolation and identification of Vibrio toranzoniae associated with diseased red conger eel (Genypterus chilensis) farmed in Chile

The present study deals with the first isolation of Vibrio toranzoniae from cultured red conger eel (Genypterus chilensis). During the summer season of 2011, mortalities were observed in young red conger eel at one aquaculture experimental rearing system in Quintay, Valparaiso, Chile. The microbiological analysis of the diseased fish resulted in the isolation of three dominant and representative isolates, designated as R.17, R.18 and R.19, which were obtained from gill, fin and external lesions from three different fish, respectively. All isolates were identified as V. toranzoniae by means of a polyphasic taxonomic approach, including phenotypic characterization, sequencing of 16S rRNA and housekeeping genes, and DNA-DNA hybridization. Inoculation of a representative strain (R18) in turbot as model fish species demonstrated the pathogenic potential for fish of the Chilean isolates. Results obtained indicate that the geographical and host distribution of V. toranzoniae is wider than expected, and that this species may have negative incidence in the culture of marine organisms.

Sequencing and de novo assembly of the red cusk-eel (Genypterus chilensis) transcriptome

The red cusk-eel (Genypterus chilensis) is an endemic fish species distributed along the coasts of the Eastern South Pacific. Biological studies on this fish are scarce, and genomic information for G. chilensis is practically non-existent. Thus, transcriptome information for this species is an essential resource that will greatly enrich molecular information and benefit future studies of red cusk-eel biology. In this work, we obtained transcriptome information of G. chilensis using the Illumina platform. The RNA sequencing generated 66,307,362 and 59,925,554 paired-end reads from skeletal muscle and liver tissues, respectively. De novo assembly using the CLC Genomic Workbench version 7.0.3 produced 48,480 contigs and created a reference transcriptome with a N50 of 846bp and average read coverage of 28.3×. By sequence similarity search for known proteins, a total of 21,272 (43.9%) contigs were annotated for their function. Out of these annotated contigs, 33.5% GO annotation results for biological processes, 32.6% GO annotation results for cellular components and 34.5% GO annotation results for molecular functions. This dataset represents the first transcriptomic resource for the red cusk-eel and for a member of the Ophidiimorpharia taxon.

Evaluating odour control technologies using reliability and sustainability criteria--a case study for water treatment plants

Technologies for odour control have been widely reviewed and their optimal range of application and performance has been clearly established. Selection criteria, mainly driven by process economics, are usually based on the air flow volume, the inlet concentrations and the required removal efficiency. However, these criteria are shifting with social and environmental issues becoming as important as process economics. A methodology is illustrated to quantify sustainability and robustness of odour control technology in the context of odour control at wastewater treatment or water recycling plants. The most commonly used odour abatement techniques (biofiltration, biotrickling filtration, activated carbon adsorption, chemical scrubbing, activated sludge diffusion and biotrickling filtration coupled with activated carbon adsorption) are evaluated in terms of: (1) sustainability, with quantification of process economics, environmental performance and social impact using the sustainability metrics of the Institution of Chemical Engineers; (2) sensitivity towards design and operating parameters like utility prices (energy and labour), inlet odour concentration (H2S) and design safety (gas contact time); (3) robustness, quantifications of operating reliability, with recommendations to improve reliability during their lifespan of operations. The results show that the odour treatment technologies with the highest investments presented the lowest operating costs, which means that the net present value (NPV) should be used as a selection criterion rather than investment costs. Economies of scale are more important in biotechniques (biofiltration and biotrickling filtration) as, at increased airflows, their reduction in overall costs over 20 years (NPV20) is more extreme when compared to the physical/chemical technologies (chemical scrubbing and activated carbon filtration). Due to their low NPV and their low environmental impact, activated sludge diffusion and biotrickling filtration are in general the most cost-effective, and probably the technologies to be considered first for odour treatment in a wastewater treatment or water recycling plant. When, in an economical and risk evaluation, the reliability is counted to be as relevant as the overall costs, a hybrid technology (biotrickling filtration with activated carbon polishing) would be comparable to biotrickling filtration and activated sludge diffusion as the most preferred technologies, when all technologies are designed to have a 99% reduction of H2S and a 95% reduction of the odour concentration.

Variación anual del polen en la atmósfera de Ponferrada. Años 1995-96

El objeto de este estudio es conocer la concentración de polen y la periodicidad anual del mismo, en la atmósfera de la ciudad de Ponferrada (León). El muestreo aerobiológico se ha realizado durante dos años consecutivos (1995-96), mediante un captador volumétrico tipo Hirst (modelo Lanzoni VPSS-2000), situado a unos 10 m del suelo. Durante este periodo se han identificado 66 tipos polínicos de ellos, 22 (96%) constituyen el espectro polínico principal, de esta estación de muestreo. Entre Enero y Julio, se produce la máxima emisión de polen al aire, y desde Septiembre a Diciembre la cantidad de polen atmósferico es muy escasa. Los tipos polínicos predominantes cuantitativamente han sido: Cupressaceae (21,3%), Poaceae (19,2%), Pinaceae (12,6%), Quercus (10%), Castanea sativa (6,2%), y Betula (3,6%), que junto con Alnus, Erica, Plantago, Populus, Rumex y Urticaceae, suponen el 91,9% del polen total de la atmósfera de Ponferrada. Se ha detectado un predominio anual de pólenes de especies leñosas frente a herbáceas. Desde el punto de vista clínico, los pólenes de Poaceae (60%) son, con mucho, los que ocasionan mayor patología polínica, seguidos de Plantago (27%) y Betula (12%). 

Serum ASAT, ALAT, ALP, LD, GT, and CK determined in the Cobas-Bio centrifugal analyser by the methods of the Scandinavian Committee on Enzymes

The recommended methods of the Scandinavian Committee on Enzymes [4, 5, 6, 7, 8] have been applied to the Cobas-Bio centrifugal analyser. Reagents and serum volumes were scaled down and final molarities were kept equal. Serum volumes in microliters were as follows: ASAT 30, ALAT 30, ALP 3, LD 5, GT 20, and CK 10. Including the dead space of the sample cup, the volume needed to perform all six tests was 113 microliter. Within-run and between-run precision (CV%) were as follows: ASAT 1.32 and 1.95, ALAT 1.68 and 2.93, ALP 1.56 and 3.10, LD 1.63 and 4.44, GT 0.81 and 2.23, and CK 1.02 and 1.94. Mean deviations (%) from target values of two commercial sera were as follows: ASAT -0.3 and -0.4, ALAT -0.4 and -2.2, ALP -1.8 and -7.3, LD 0.4 and -6.2, GT 13.9 and -10.7, and CK -4.9 and -1.3. Results of all the methods correlated well with those obtained with their respective manual methods. Analytical time for 28 samples of each analyte was 10 min, apart from CK which was 14 min. Reagent cost per sample was 0.6, 0.9, 0.1, 0.3, 0.9, and 26 US cents respectively. All reagents were prepared in the laboratory, except those for CK which were bought from J.T. Baker (Phillipsburgh, NJ, USA). In conclusion, the methods keep the features of the manual methods but they are more precise and practicable, much faster and cheaper, and use minimal amounts of sera more convenient for paediatric work.