Lactobacillus rhamnosus lowers zebrafish lipid content by changing gut microbiota and host transcription of genes involved in lipid metabolism.

The microbiome plays an important role in lipid metabolism but how the introduction of probiotic communities affects host lipid metabolism is poorly understood. Using a multidisciplinary approach we addressed this knowledge gap using the zebrafish model by coupling high-throughput sequencing with biochemical, molecular and morphological analysis to evaluate the changes in the intestine. Analysis of bacterial 16S libraries revealed that Lactobacillus rhamnosus was able to modulate the gut microbiome of zebrafish larvae, elevating the abundance of Firmicutes sequences and reducing the abundance of Actinobacteria. The gut microbiome changes modulated host lipid processing by inducing transcriptional down-regulation of genes involved in cholesterol and triglycerides metabolism (fit2, agpat4, dgat2, mgll, hnf4α, scap, and cck) concomitantly decreasing total body cholesterol and triglyceride content and increasing fatty acid levels. L. rhamnosus treatment also increased microvilli and enterocyte lengths and decreased lipid droplet size in the intestinal epithelium. These changes resulted in elevated zebrafish larval growth. This integrated system investigation demonstrates probiotic modulation of the gut microbiome, highlights a novel gene network involved in lipid metabolism, provides an insight into how the microbiome regulates molecules involved in lipid metabolism, and reveals a new potential role for L. rhamnosus in the treatment of lipid disorders

Combined effects of exogenous enzymes and probiotic on Nile tilapia (Oreochromis niloticus) growth, intestinal morphology and microbiome

A study was carried out to investigate the combined effect of exogenous enzymes and probiotic supplementation on tilapia growth, intestinal morphology and microbiome composition. Tilapia (34.56 ± 0.05 g) were fed one of four diets (35% protein, 5% lipid); one of which was a control and the remaining three diets were supplemented with either enzymes (containing phytase, protease and xylanase), probiotic (containing Bacillus subtilis, Bacillus licheniformis and Bacillus pumilus) or enz-pro (the combination of the enzymes and probiotic). Tilapia fed diet supplemented with enz-pro performed better (P < 0.05) than tilapia fed the control and probiotic supplemented diets in terms of final body weight (FBW), specific growth rate (SGR), feed conversion ratio (FCR) and protein efficiency ratio (PER). The dietary treatments did not affect somatic indices. The serum lysozyme activity was significantly higher (P < 0.05) in tilapia fed the probiotic supplemented diet than of those fed the remaining experimental diets. The intestinal perimeter ratio was higher (P < 0.05) in tilapia fed enz-pro supplemented diet when compared to those fed with the control and probiotic supplemented diets. Goblet cells abundance, microvilli diameter and total enterocyte absorptive surface was higher (P < 0.05) in tilapia fed diet supplemented with enz-pro than those fed the control diet. High-throughput sequencing revealed that majority of reads derived from the tilapia digesta belonged to members of Fusobacteria (predominantly Cetobacterium) distantly followed by Proteobacteria and Firmicutes. The alpha and beta diversities did not differ among dietary treatments indicating that the overall microbial community was not modified to a large extent by dietary treatment. In conclusion, supplementation of the diet with a combination of enzymes and probiotic is capable of improving tilapia growth and intestinal morphology without deleterious effect on the intestinal microbial composition

A systematic analysis of host factors reveals a Med23-interferon-λ regulatory axis against herpes simplex virus type 1 replication

Herpes simplex virus type 1 (HSV-1) is a neurotropic virus causing vesicular oral or genital skin lesions, meningitis and other diseases particularly harmful in immunocompromised individuals. To comprehensively investigate the complex interaction between HSV-1 and its host we combined two genome-scale screens for host factors (HFs) involved in virus replication. A yeast two-hybrid screen for protein interactions and a RNA interference (RNAi) screen with a druggable genome small interfering RNA (siRNA) library confirmed existing and identified novel HFs which functionally influence HSV-1 infection. Bioinformatic analyses found the 358 HFs were enriched for several pathways and multi-protein complexes. Of particular interest was the identification of Med23 as a strongly anti-viral component of the largely pro-viral Mediator complex, which links specific transcription factors to RNA polymerase II. The anti-viral effect of Med23 on HSV-1 replication was confirmed in gain-of-function gene overexpression experiments, and this inhibitory effect was specific to HSV-1, as a range of other viruses including Vaccinia virus and Semliki Forest virus were unaffected by Med23 depletion. We found Med23 significantly upregulated expression of the type III interferon family (IFN-λ) at the mRNA and protein level by directly interacting with the transcription factor IRF7. The synergistic effect of Med23 and IRF7 on IFN-λ induction suggests this is the major transcription factor for IFN-λ expression. Genotypic analysis of patients suffering recurrent orofacial HSV-1 outbreaks, previously shown to be deficient in IFN-λ secretion, found a significant correlation with a single nucleotide polymorphism in the IFN-λ3 (IL28b) promoter strongly linked to Hepatitis C disease and treatment outcome. This paper describes a link between Med23 and IFN-λ, provides evidence for the crucial role of IFN-λ in HSV-1 immune control, and highlights the power of integrative genome-scale approaches to identify HFs critical for disease progression and outcome

Morfometría de las especies de Vieja (Cichlidae) en ríos de la cuenca del Usumacinta, Chiapas, México

Se evaluaron y compararon diversas características morfológicas de 6 especies de Vieja Fernández-Yépez, 1969 del río Usumacinta. Se emplearon 20 organismos adultos por especie y 33 medidas corporales que fueron estandarizadas y examinadas con un análisis discriminante. Además se comparó la forma del cuerpo entre las especies, mediante el análisis de morfometría geométrica a partir de imágenes digitalizadas. El análisis con la morfometría tradicional y geométrica permitió diferenciar los seis taxones. Se encontraron 10 medidas discriminantes, que expresan diferencias significativas en la longitud de las aletas y la región cefálica, de las cuales la posición de la boca diferenció estadísticamente más taxones. Las relaciones de similitud con ambos análisis mostraron 2 grupos, siendo V. bifasciata (Steindachner, 1864) y V. synspila (Hubbs, 1935) las especies más parecidas. Las gradillas de deformación mostraron que la mayor variación está en la región cefálica, específicamente en la posición de la boca y los ojos. Las diferencias morfométricas encontradas pueden servir para la determinación taxonómica en trabajos futuros. La variación encontrada en la morfología cefálica y trófica puede ser un mecanismo que favorece la coexistencia de las especies y la diversidad del grupo en la región

Lista de Peces Continentales de Chiapas, México

An ichthyofaunal checklist of the continental waters of Chiapas is presented, including freshwater species and those marine fishes that penetrate seasonally, occasionally, or permanently into estuaries and coastal lagoons. The list is based primarily on records in the Fish Collection of ECOSUR at San Cristóbal de las Casas, as well as records in other collections and the literature. A total of 207 species is documented, including nine introduced. The fauna consists of 110 genera in 45 families and 20 orders. Ten families contained 66% of the total species richness: Cichlidae, Poeciliidae, Carangidae, Sciaenidae, Ariidae, Centropomidae, Characidae, Gerreidae, Haemulidae, and Engraulidae.Se presenta una lista sistemática de la ictiofauna continental del Estado de Chiapas, desde las formas dulceacuícolas, hasta las marinas que penetran estacional, ocasional o permanentemente a los estuarios y sistemas lagunares. La información se basa principalmente en los registros de la Colección de Peces de ECOSUR en San Cristóbal de las Casas, así como en los registros de otras colecciones y en un análisis de la literatura. La lista está documentada por 207 especies de las cuales nueve son introducidas; están distribuidas en 110 géneros de 45 familias y 20 órdenes. Diez familias agrupan el 66% de la riqueza total de especies: Cichlidae, Poeciliidae, Carangidae, Sciaenidae, Ariidae, Centropomidae, Characidae, Gerreidae, Haemulidae y Engraulidae

Análisis morfométrico de los peces del grupo labialis, género Profundulus (Cyprinodontiformes: Profundulidae), en Chiapas, México

SE PRESENTAN LOS RESULTADOS DE LA COMPARACIÓN MORFOMÉTRICA DE LAS ESPECIES DEL ”COMPLEJO LABIALIS”, DEL GÉNERO PROFUNDULUS, BASADA EN 11 MEDIDAS TRADICIONALES Y 21 CRUZADAS. MEDIANTE EL ANÁLISIS DE COMPONENTES PRINCIPALES Y AGRUPAMIENTO SE DEMOSTRÓ QUE PROFUNDULUS LABIALIS Y P. CANDALARIUS MUESTRAN UN PATRÓN MORFOLÓGICO SEMEJANTE, CARACTERIZADO POR MAYOR ALTURA DEL CUERPO, MENOR LONGITUD DEL HOCICO, Y MENOR LONGITUD Y ANCHO DE LA BOCA; MIENTRAS QUE P. HILDEBRANDI PRESENTA CARACTERÍSTICAS DIFERENTES. EL ANÁLISIS DE VARIANZA MOSTRÓ 14 MEDIDAS MORFOMÉTRICAS ESTADÍSTICAMENTE SIGNIFICATIVAS QUE PERMITEN SEPARAR, POR LO MENOS, A UNA DE LAS TRES ESPECIES Y ADEMÁS CORROBORAN SU VALIDEZ TAXONÓMICA. LAS RELACIONES DE SIMILITUD ESTABLECIDAS EN ESTE ANÁLISIS CONCUERDAN CON LAS RELACIONES FILOGENÉTICAS PROPUESTAS POR OTROS AUTORES. LAS DIFERENCIAS ENCONTRADAS EN MEDIDAS RELACIONADAS CON ESTRUCTURAS TRÓFICAS Y DE LA ALTURA DEL CUERPO PODRÍAN ESTAR RELACIONADAS CON ASPECTOS ECOLÓGICOS O ASOCIACIONES CON DISTINTOS HÁBITATS

Geometric morphometric comparison of the oral jaw and lower pharyngeal jaw of the closely-related cichlid, Vieja bifasciata, V. breidohri and V. hartwegi (Cichliformes: Cichlidae)

Systematics of the genus Vieja is complex, with many morphologically similar species that have little genetic differentiation. Examination of additional morphological traits can be useful for clarifying their taxonomic status and evolutionary history. We analyzed morphological variation of bones in the oral jaw and lower pharyngeal jaw to determine if these structures permit delimitation of species and to study possible functional implications. Morphological differences were quantified from canonical variates analysis, MANOVA, and paired comparisons. Differences in the number of pharyngeal teeth in the lower pharyngeal jaw were determined using an ANCOVA. The shape of the premaxilla and lower pharyngeal jaw are best for differentiating between these closely related-species. Although the morphological variation between V. breidohri and V. hartwegi were most similar, the shape of the lower pharyngeal jaw contrasts in morphospace. Vieja bifasciata possesses more teeth in the lower pharyngeal jaw. Variation in this bones may effect jaw biomechanics. Morphological differences are in contrast with the little genetic differentiation observed. The geographic isolation of V. bifasciata is likely related to its morphological differentiation. The common ancestry of V. breidohri and V. hartwegi probably explains their small morphological divergence.

Diversidad íctica en la cuenca del Usumacinta, México

La cuenca del río Usumacinta se caracteriza por su gran extensión, heterogeneidad ecológica y alta biodiversidad. Con el objetivo de documentar de manera integral la riqueza y distribución de la ictiofauna, se incluyen en este trabajo los registros para la cuenca (1994-2014) depositados en la Colección de Peces (ECOSC), además de la revisión bibliográfica y de los registros de otras bases de datos nacionales e internacionales. Adicionalmente y con la finalidad de analizar la diversidad y abundancia, se realizaron muestreos (2014 y 2015) en 3 zonas: selva, planicie y delta. La ictiofauna se compone de 2 clases, 28 órdenes, 50 familias y 172 especies, de las cuales 3 son nuevos registros. De acuerdo a su afinidad ecológica, 75 especies son dulceacuícolas, 8 estuarinas y 89 marinas. La zona selva tuvo más especies dulceacuícolas exclusivas y la zona delta registró la mayor riqueza de peces marinos. Los cambios observados en la diversidad a lo largo de las 3 zonas están influidos por la historia geológica, dinámica hidrológica y su conectividad con el golfo de México. Es necesario continuar con el estudio de la ictiofauna en función de la complejidad geomorfológica para entender patrones biogeográficos, así como procesos ecológicos importantes para su conservación

Influence of different bottom types on the Senegal sole Solea senegalensis Kaup, 1858 ongrowing

Fish coloration may affect its market value. The present paper compares growth, survival rate and pigmentation during the ongrowing of Senegal sole Solea senegalensis Kaup, 1858 on three different bottoms. This experiment lasted five months, and at the beginning fish were 4.93 ± 0.75 cm (length) and 1.91 ± 0.68 g (weight). No significant differences were found for final length and weight between different bottoms. Several pigmentation patterns were found on the sand and white bottoms, but one single pattern appeared in the dark bottom tanks. The survival rate on the sand bottom was significantly less than others, probably due to pathologies stemming from the difficult maintenance of the sand bed.La falta de homogeneidad en la coloración de los peces puede afectar a su valor comercial. En este trabajo se ha comparado el crecimiento, la supervivencia y la pigmentación de ejemplares de lenguado senegalés Solea senegalensis Kaup, 1858 durante el preengorde en tanques con tres tipos de fondos. El experimento tuvo una duración de 5 meses. El tamaño inicial de los individuos era 4,93 ± 0,75 cm y 1,91 ± 0,68 g, y al final de la experiencia no se encontraron diferencias significativas entre las tallas y los pesos de los ejemplares de los distintos tanques. Se detectaron varios patrones de pigmentación en los especímenes correspondientes a los fondos arenoso y blanco, pero solo uno en los de los tanques de fondo gris. La supervivencia en el fondo de arena fue la menor de todas (p 0,01), probablemente atribuible a patologías asociadas al difícil mantenimiento del lecho arenoso.Instituto Español de Oceanografí