Search

Elongation of very long‐chain fatty acid 4 (Elovl4) proteins participate in the biosynthesis of very long‐chain (>C24) saturated and polyunsaturated fatty acids (FA). Previous studies have shown that fish possess two different forms of Elovl4, termed Elovl4a and Elovl4b. The present study aimed to characterize both molecularly and functionally two elovl4 cDNA from the African catfish Clarias gariepinus. The results confirmed that C. gariepinus possessed two elovl4‐like elongases with high homology to two previously characterized Elovl4 from Danio rerio, and thus they were termed accordingly as Elovl4a and Elovl4b. The C. gariepinus Elovl4a and Elovl4b have open reading frames (ORF) of 945 and 915 base pairs, respectively, encoding putative proteins of 314 and 304 amino acids, respectively. Functional characterization in yeast showed both Elovl4 enzymes have activity towards all the PUFA substrates assayed (18:4n‐3, 18:3n‐6, 20:5n‐3, 20:4n‐6, 22:5n‐3, 22:4n‐6 and 22:6n‐3), producing elongated products of up to C36. Moreover, the C. gariepinus Elovl4a and Elovl4b were able to elongate very long‐chain saturated FA (VLC‐SFA) as denoted by increased levels of 28:0 and longer FA in yeast transformed with elovl4 ORF compared to control yeast. These results confirmed that C. gariepinus Elovl4 play important roles in the biosynthesis of very long‐chain FA. Tissue distribution analysis of elovl4 mRNAs showed both genes were widely expressed in all tissues analyzed, with high expression of elovl4a in pituitary and brain, whereas female gonad and pituitary had the highest expression levels for elovl4b

Artemia nauplii catabolize polyunsaturated fatty acids (PUFA); in particular, they retroconvert docosahexaenoic acid (DHA, 22:6n‐3), so enrichment is a continuous quest towards increasing PUFA through the use of PUFA‐rich enrichment products. However, optimal conditions during enrichment (aeration, illumination and temperatures around 28°C) tend to accelerate autoxidation of PUFA and the formation of potentially toxic oxidation products. Water‐soluble antioxidants like the polyphenolic compound hydroxytyrosol (3,4‐dihydroxyphenylethanol), a polar molecule found in the water fraction resulting after the milling process of olives, arise as promising compounds to prevent oxidation during Artemia enrichments. We investigated the antioxidant activity and lipid peroxidation in Artemia nauplii during enrichment and the effect of adding an external antioxidant based on hydroxytyrosol during the enrichment with a PUFA‐rich emulsion (M70). For this purpose, the activity of antioxidant enzymes (catalase, superoxide dismutase, glutathione‐S‐transferase, glutathione peroxidase), as well as lipid peroxidation, was determined in enriched and unenriched Artemia nauplii. To validate antioxidant activity and lipid peroxidation, in a first experiment, nauplii were enriched with microalgae (Tetraselmis suecica), yeast (Saccharomyces cerevisiae) and M70 emulsion. In a second experiment, enrichment with a commercial emulsion (DC Super Selco), M70, and a combination of M70 and hydroxytyrosol (Hytolive, HYT) added as an external antioxidant were performed. The combination of M70 with HYT produced the best results, in terms of activity of antioxidant enzymes. The analysis of the fatty acids from total lipids showed that the addition of hydroxytyrosol preserved the DHA percentage of enriched nauplii

Elongase of very long‐chain fatty acids (Elovl) 4 probably plays a crucial role in marine fish species, where lack of Elovl2 has been considered as one possible reason for their low long‐chain polyunsaturated fatty acids' (LC‐PUFAs) biosynthetic capability. Elongase of very long‐chain fatty acids 4 is the most recent member of the Elovl family that has been investigated in fish. Here, we report the molecular cloning and functional characterization of putative elovl4 cDNA isolated from marine teleost, Epinephelus coioides, and its expression in response to dietary n‐3 LC‐PUFA and docosahexaenoic acid (DHA) to eicosapentaenoic acid (EPA) ratio. The elovl4 cDNA of grouper was 2341 bp including 301 bp of 5′‐untranslated region (UTR), 918 bp of the coding region that encodes 305 amino acids (AA) and 1122 bp of 3′UTR. Heterologous expression in yeast demonstrated that grouper Elovl4 could elongate saturated fatty acids (FA), especially 24:0 and 26:0, up to 36:0. Also, grouper Elovl4 effectively converted C20 and C22 polyunsaturated FAs to elongated polyenoic products up to C36. Tissue distribution analysis revealed that Elovl4 were widely transcribed in various tissues with the highest level in eye, brain and testis as described in other teleosts. The transcript level of elovl4 was significantly affected by dietary n‐3 LC‐PUFA and high LC‐PUFA level repressess its expression. However, the ratio of DHA to EPA had no significant influence on its expression. These results may contribute to better understanding the LC‐PUFA biosynthetic pathway in this fish species.

The common octopus (Octopus vulgaris) is a promising species for aquaculture diversification, but massive mortality during the first life-cycle stages (paralarvae) is the main bottleneck for its commercial production in captivity. The aim of this study was to assess stress and nutritional condition biomarkers (HSP70, ROS enzymes and lipid peroxidation) (RNA/DNA, RNA/protein, protein/DNA and protein) in O. vulgaris paralarvae from different geographical origins and fed with Artemia enriched with marine phospholipids or microalgae (control group). To this end paralarvae were cultured for 30 days, in three different centres in Spain (Tarragona-Mediterranean area, Tenerife-Central Atlantic area and Vigo-North Atlantic area), under the same protocol, and fed on Artemia enriched with marine phospholipids (LC60) (Marine Lecithin LC 60®, PhosphoTech Laboratoires) or microalgae (control group). Dry weight and most biomarkers analysed in hatchlings showed significant differences related to their origin (centre). Fifteen day old paralarvae presented significant differences in specific growth rate (SGR) associated with their dietary regime, and also showed differences in biomarkers associated both with their geographical origin and dietary regime. The results suggest that the SGR of paralarvae were positively influenced by LC60, promoting growth and in agreement with the results of nutritional condition biomarkers (nucleic acids ratios). The antioxidant defences against oxidative damage were also boosted in the LC60 paralarvae group, possibly as a result of the elevated content in highly polyunsaturated fatty acids. In addition, the partial correlations found between biomarkers varied according to diet. However, no positive effect of LC60 on survival was observed. The high variability found among geographical origins, despite the use of the same rearing protocol, highlights the need to clarify the sources of such variability.

Triatoma sordida is widely distributed throughout the Chaco and the Eastern Region of Paraguay. It is associated to palm trees and artificial ecotopes located in peridomestic environments.The aim of this work was to determine genetic and morphometric variability and feeding behavior among population ofT. sordida captured in domicile and peridomicile areas of Paraguay. Feeding contents and levels of genetic and morphometric variationwere determined in 124 T. sordida from domicile and peridomicile populations of San Pedro and Paraguarí departments of the Eastern Region and Boquerón and Presidente Hayes departments of the Western region using Double Diffusion Gel, random amplified polymorphic DNA (RAPD), and head and wings morphometry. Morphometric analysis revealed isolation of populations by geographic region and larger size in triatomine populations from the Western Region. RAPD showed no specific patterns for domicile and peridomicile populations. The estimator of diversity (FST; 0.08) and high gene flow obtained (Nm; 5.7) did not allow the establishment of genetic differentiation within the same region. The blood meal source showed that poultry feeding was 38% of host preferences, and human blood was the second feeding preference (24%) in the insects from the Eastern Region while poultry feeding was predominant in those from the Western Region (30%). This work showed homogeneity between T. sordida populations of the same region and between domicile and peridomicile. The genetic diversity was determined among T. sordida populations of both geographical regions suggesting differentiation associated to eco-geographical isolation by distance. It is important to notice that pattern feedings were different between the two regions. Further studies should be focused on how phenetic and genetic variations could be related to the adaptation capacity of these triatomine populations to domicile, increasing their vector potentiality in the transmission of Chagas disease.

The present research work, in the first instance, defines the construct poverty and vulnerability, the reasons why poverty and vulnerability were nested in Latin America and of course in Mexico. In the same way, the investigation evidences the levels of poverty existing in Mexico at present, as well as, its causes particularly in the State of Yucatan, to later make a revision and analysis on different cases of success in the fight against poverty, economic and social development through human, intellectual and social capital development strategies, in countries whosesocioeconomic characteristics are similar to living conditions in Mexico and the State of Yucatan, in order to understand why these other economies (mainly the Eastern of Asia) have achieved great progress in terms of economic and social development, while Mexico, despite its great economic capacity, has not been able to achieve the same results in terms of poverty and vulnerability reduction, economic and social development refer. To conclude and recommend complementary guidelines that the Yucatecan society could implement, to improve the welfare levels of population in Tekax., El presente artículo define el constructo de pobreza y vulnerabilidad, las razones por las cuales la pobreza y la vul-nerabilidad se anidaron en latinoamérica y, desde luego, en México. Del mismo modo, la investigación evidencia los niveles de pobreza existentes en México en la actualidad, así como sus causas, particularmente en el municipio de Tekax, estado de Yucatán. Posteriormente, se hace una revisión y análisis sobre diferentes casos de éxito en combate a la pobreza, desarrollo económico y social por medio de estrategias de desarrollo de capital humano, intelectual y social, en países cuyas características socioeconómicas eran similares a las condiciones de vida en México y el estado de Yucatán. De esta manera, se busca comprender por qué otras economías (principalmente las del este asiático) han logrado tener grandes avances en materia de desarrollo económico y social, mientras que México, a pesar de su gran capacidad económica, no ha podido de alcanzar los mismos resultados en cuanto a reducción de pobreza y vulnerabilidad, desarrollo económico y social. Para finalizar, con conclusiones y recomen-daciones sobre directrices complementarias que la sociedad yucateca podría implementar, para mejorar los niveles de bienestar de la población en Tekax.

La Organización Mundial para la Agricultura y la Alimentación (Food and Agriculture Organization of the United Nations, FAO) y la Comisión Europea definen la acuicultura como “el cultivo de organismos acuáticos, incluyendo peces, moluscos, crustáceos y plantas acuáticas, en aguas continentales y costeras, que implica la intervención del hombre en el proceso de cría para aumentar la producción en operaciones como la siembra, la alimentación, la protección contra depredadores, etc.”. La acuicultura a pequeña escala ha existido desde tiempos antiguos en varios países. Estos orígenes están documentados desde el 2500 A.C., pero no es hasta mediados del siglo XX cuando se inicia una evolución hacia la producción industrial a gran escala. En el transcurso de medio siglo la acuicultura ha pasado de ser prácticamente insignificante a equipararse con la producción de pesca de captura. Este sector ha tenido que evolucionar, incluir innovaciones técnicas y adaptarse para satisfacer las necesidades de la población. Debido al crecimiento demográfico de estos últimos siglos, se ha observado una sobreexplotación de los recursos pesqueros, con lo que el desarrollo de la acuicultura a gran escala juega un papel vital en la sociedad actual

A short term exposure experiment (72 h) to permethrin (PER) of the clam Donax trunculus from the Tunisian coast was carried out. Changes in the lipid classes, fatty acid (FA) composition and lipid peroxidation were determined in the gills of adults and juveniles. A significant decrease of total lipid content was followed by a decrease in polar lipids (PL) and polyunsaturated fatty acids (PUFAs) especially n-3 and n-6. As, for the oxidative stress response, a significant elevation in lipid peroxidation (LPO) was found after the exposure of both adults and juveniles.

Elongation of very-long chain fatty acid (Elovl) proteins are enzymes that catalyse the condensation reaction, the first and rate-limiting step out of four sequential reactions required for the elongation of fatty acids (FAs) (Jakobsson et al., 2006). Seven members (Elovl1-7) make up the elongase protein family in vertebrates, with Elovl4 having a major role in the biosynthesis of very long-chain (≥ C24) FAs of both saturated and polyunsaturated (VLC-PUFA) acyl chains (Agbaga et al., 2008). Recent studies have shown that fish possess two different forms of Elovl4, namely Elovl4a and Elovl4b, with different functions and spatial-temporal expression patterns during development (Monroig et al., 2010). We have recently initiated the investigation of Elovl and fatty acyl desaturase (Fads) genes that participate in the biosynthesis of essential FAs in Clarias gariepinus, a commercially important fish species in Africa (Oboh et al., 2016). In this study, we aimed to characterise both molecularly and functionally two elovl4 cDNAs from C. gariepinus, and investigate their tissue distribution

Very long-chain polyunsaturated fatty acids (VLC-PUFA), compounds with unusually long acyl chains (>C24), have been scarcely investigated in fish. Studies in mammals have demonstrated that VLC-PUFA, biosynthesized from shorter-chain precursors by fatty acyl elongases termed Elovl4, play key roles in the function of eye, brain and gonads. Many of the physiological processes in which VLC-PUFA are involved are particularly crucial in fast-growing life stages of animals, when biomembranes in which VLC-PUFA accumulate are developing. The situation can further aggravate when, along with rapid growth rates, dietary deficiencies of metabolic precursors occur. In the context of fish farming, a combination of both factors (fast growth and dietary deficiencies) often applies to the culture of juveniles of marine species that are currently fed diets with low levels of fish oil (FO), potentially limiting precursors for VLC-PUFA biosynthesis. The present study aimed to characterize the Elovl4 complement and their nutritional regulation in juveniles of gilthead seabream (Sparus aurata) fed diets with varying levels of FO. Our results demonstrated that S. aurata possesses two elovl4 genes (elovl4a and elovl4b). The function of the S. aurata Elovl4 enzymes was assessed in yeast. Both Elovl4 enzymes showed the ability to elongate C20 (20:5n-3 and 20:4n-6) and C22 (22:5n-3 and 22:4n-6) substrates to longer products, which produced in some cases VLC-PUFA of up to C32. Tissue expression analysis of elovl4 confirmed that eye and brain are sites of VLC-PUFA biosynthesis in seabream juveniles. We further investigated the nutritional regulation of VLC-PUFA biosynthetic genes in seabream juveniles fed diets with different FO levels for four months. While elovl4b appeared not to be regulated in eye and brain, elovl4a was down-regulated (P<0.05) in both tissues with decreased dietary FO inclusion, possibly suggesting that expression may be related to precursor availability and that low dietary