A Multi-Component Pheromone in the Urine of Dominant Male Tilapia (Oreochromis mossambicus) Reduces Aggression in Rivals.

Males often use scent to communicate their dominance, and to mediate aggressive and breeding behaviors. In teleost fish, however, the chemical composition of male pheromones is poorly understood. Male Mozambique tilapia, Oreochromis mossambicus, use urine that signals social status and primes females to spawn.

Revisiting in vivo staining with alizarin red S--a valuable approach to analyse zebrafish skeletal mineralization during development and regeneration.

Background: The correct evaluation of mineralization is fundamental for the study of skeletal development, maintenance, and regeneration. Current methods to visualize mineralized tissue in zebrafish rely on: 1) fixed specimens; 2) radiographic and μCT techniques, that are ultimately limited in resolution; or 3) vital stains with fluorochromes that are indistinguishable from the signal of green fluorescent protein (GFP)-labelled cells. Alizarin compounds, either in the form of alizarin red S (ARS) or alizarin complexone (ALC), have long been used to stain the mineralized skeleton in fixed specimens from all vertebrate groups.

MEF2C orthologues from zebrafish: Evolution, expression and promoter regulation.

MEF2C is a crucial transcription factor for cranial neural crest cells development. An abnormal expression of this protein leads to severe abnormalities in craniofacial features. Recently, a human disease (MRD20) was described as a consequence of MEF2C haploinsufficiency.

Habitat use and diel vertical migration of bigeye thresher shark: Overlap with pelagic longline fishing gear.

Pelagic longliners targeting swordfish and tunas in oceanic waters regularly capture sharks as bycatch, including currently protected species as the bigeye thresher, Alopias superciliosus. Fifteen bigeye threshers were tagged with pop-up satellite archival tags (PSATs) in 2012-2014 in the tropical northeast Atlantic, with successful transmissions received from 12 tags for a total of 907 tracking days. Marked diel vertical movements were recorded on all specimens, with most of the daytime spent in deeper colder water (mean depth = 353 m, SD = 73; mean temperature = 10.

Specificity in Mesograzer-Induced Defences in Seagrasses.

Grazing-induced plant defences that reduce palatability to herbivores are widespread in terrestrial plants and seaweeds, but they have not yet been reported in seagrasses. We investigated the ability of two seagrass species to induce defences in response to direct grazing by three associated mesograzers. Specifically, we conducted feeding-assayed induction experiments to examine how mesograzer-specific grazing impact affects seagrass induction of defences within the context of the optimal defence theory.

Transcriptional regulation of gilthead seabream bone morphogenetic protein (BMP) 2 gene by bone- and cartilage-related transcription factors.

Bone morphogenetic protein (BMP) 2 belongs to the transforming growth factor β (TGFβ) superfamily of cytokines and growth factors. While it plays important roles in embryo morphogenesis and organogenesis, BMP2 is also critical to bone and cartilage formation. Protein structure and function have been remarkably conserved throughout evolution and BMP2 transcription has been proposed to be tightly regulated, although few data is available.

Iron overload in a murine model of hereditary hemochromatosis is associated with accelerated progression of osteoarthritis under mechanical stress.

Objective: Hereditary hemochromatosis (HH) is a disease caused by mutations in the Hfe gene characterised by systemic iron overload and associated with an increased prevalence of osteoarthritis (OA) but the role of iron overload in the development of OA is still undefined. To further understand the molecular mechanisms involved we have used a murine model of HH and studied the progression of experimental OA under mechanical stress.

Design: OA was surgically induced in the knee joints of 10-week-old C57BL6 (wild-type) mice and Hfe-KO mice.

Comparative analysis of zebrafish bone morphogenetic proteins 2, 4 and 16: molecular and evolutionary perspectives.

BMP2, BMP4 and BMP16 form a subfamily of bone morphogenetic proteins acting as pleiotropic growth factors during development and as bone inducers during osteogenesis. BMP16 is the most recent member of this subfamily and basic data regarding protein structure and function, and spatio-temporal gene expression is still scarce. In this work, insights on BMP16 were provided through the comparative analysis of structural and functional data for zebrafish BMP2a, BMP2b, BMP4 and BMP16 genes and proteins, determined from three-dimensional models, patterns of gene expression during development and in adult tissues, regulation by retinoic acid and capacity to activate BMP-signaling pathway.

Gla-rich protein is involved in the cross-talk between calcification and inflammation in osteoarthritis.

Osteoarthritis (OA) is a whole-joint disease characterized by articular cartilage loss, tissue inflammation, abnormal bone formation and extracellular matrix (ECM) mineralization. Disease-modifying treatments are not yet available and a better understanding of osteoarthritis pathophysiology should lead to the discovery of more effective treatments. Gla-rich protein (GRP) has been proposed to act as a mineralization inhibitor and was recently shown to be associated with OA in vivo.

Cardiomyocyte H9c2 cells present a valuable alternative to fish lethal testing for azoxystrobin.

The present study aims at identifying, among six mammalian and fish cell lines, a sensitive cell line whose in vitro median inhibitory concentration (IC50) better matches the in vivo short-term Sparus aurata median lethal concentration (LC50). IC50s and LC50 were assessed after exposure to the widely used fungicide azoxystrobin (AZX). Statistical results were relevant for most cell lines after 48 h of AZX exposure, being H9c2 the most sensitive cells, as well as the ones which provided the best prediction of fish toxicity, with a LC50,96h/IC50,48h = 0.

Responses of seagrass to anthropogenic and natural disturbances do not equally translate to its consumers.

Coastal communities are under threat from many and often co-occurring local (e.g., pollution, eutrophication) and global stressors (e.

Effects on the metabolism, growth, digestive capacity and osmoregulation of juvenile of Sub-Antarctic Notothenioid fish Eleginops maclovinus acclimated at different salinities.

In this study we assessed the influence of three different environmental salinities (5, 15 and 31 psu during 90 days) on growth, osmoregulation, energy metabolism and digestive capacity in juveniles of the Notothenioid fish Eleginops maclovinus. At the end of experimental time samples of plasma, liver, gill, intestine, kidney, skeletal muscle, stomach and pyloric caeca were obtained. Growth, weight gain, hepatosomatic index and specific growth rate increased at 15 and 31 psu and were lower at 5 psu salinity.

Transcription factors from Sox family regulate expression of zebrafish Gla-rich protein 2 gene.

GRP is a vitamin K-dependent protein with orthologs in all vertebrate taxonomic groups and two paralogs in teleosts. However, no data is available about GRP transcriptional gene regulation. We report a functional promoter for zebrafish grp2 gene regulated by Sox9b, Sox10, Ets1 and Mef2ca as determined by in vitro assays.

Draft Genome Sequence of Aliivibrio fischeri Strain 5LC, a Bacterium Retrieved from Gilthead Sea Bream (Sparus aurata) Larvae Reared in Aquaculture.

To shed light on the putative host-mediated lifestyle of the quintessential marine symbiont Aliivibrio fischeri, and on the symbiosis versus potentially pathogenic features of bacteria associated with farmed fish, we report the draft genome sequence of A. fischeri strain 5LC, a bacterium retrieved from gilthead sea bream (Sparus aurata) larvae.

Intraspecific genetic lineages of a marine mussel show behavioural divergence and spatial segregation over a tropical/subtropical biogeographic transition.

Background: Intraspecific variability is seen as a central component of biodiversity. We investigated genetic differentiation, contemporary patterns of demographic connectivity and intraspecific variation of adaptive behavioural traits in two lineages of an intertidal mussel (Perna perna) across a tropical/subtropical biogeographic transition.

Results: Microsatellite analyses revealed clear genetic differentiation between western (temperate) and eastern (subtropical/tropical) populations, confirming divergence previously detected with mitochondrial (COI) and nuclear (ITS) markers.

Draft Genome Sequence of Vibrio sp. Strain Vb278, an Antagonistic Bacterium Isolated from the Marine Sponge Sarcotragus spinosulus.

We report here the draft genome sequence of Vibrio sp. Vb278, a biofilm-producing strain isolated from the marine sponge Sarcotragus spinosulus, showing in vitro antibacterial activity. The annotated genome displays a range of symbiotic factors and the potential for the biosynthesis of several biologically active natural products.

StemChecker: a web-based tool to discover and explore stemness signatures in gene sets.

Stem cells present unique regenerative abilities, offering great potential for treatment of prevalent pathologies such as diabetes, neurodegenerative and heart diseases. Various research groups dedicated significant effort to identify sets of genes-so-called stemness signatures-considered essential to define stem cells. However, their usage has been hindered by the lack of comprehensive resources and easy-to-use tools.

Cloning, characterization and analysis of the 5' regulatory region of zebrafish xpd gene.

The gene XPD/ERCC2 encodes an ATP-dependent 5'-3' helicase of 760 amino acids. There are few transcription factors known to be involved in the regulation of XPD, and these include the hypoxia-inducible factor-1α (HIF-1α), p53, hepatitis B virus x protein (HBx) and specificity protein 1 (Sp1). To identify functional elements of xpd gene in fish we employed a comparative genomic approach.

Zebrafish vitamin K epoxide reductases: expression in vivo, along extracellular matrix mineralization and under phylloquinone and warfarin in vitro exposure.

Vitamin K (VK) acts as a cofactor driving the biological activation of VK-dependent proteins and conferring calcium-binding properties to them. As a result, VK is converted into VK epoxide, which must be recycled by VK epoxide reductases (Vkors) before it can be reused. Although VK has been shown to play a central role in fish development, particularly during skeletogenesis, pathways underlying VK actions are poorly understood, while good and reliable molecular markers for VK cycle/homeostasis are still lacking in fish.

Lack of evidence for a role of olfaction on first maturation in farmed sea bass Dicentrarchus labrax.

Chemical communication is widespread in the animal kingdom and olfaction constitutes a powerful channel for social and environmental cues. In fish, olfactory stimuli are known to influence physiological processes, including reproduction. Here we investigate the effects of olfaction on puberty in European sea bass Dicentrarchus labrax males.

Vasotocin and isotocin regulate aquaporin 1 function in the sea bream.

Aquaporins (AQPs) are specific transmembrane water channels with an important function in water homeostasis. In terrestrial vertebrates, AQP2 function is regulated by vasopressin (AVP) to accomplish key functions in osmoregulation. The endocrine control of aquaporin function in teleosts remains little studied.

Gla-rich protein acts as a calcification inhibitor in the human cardiovascular system.

Objective: Vascular and valvular calcifications are pathological processes regulated by resident cells, and depending on a complex interplay between calcification promoters and inhibitors, resembling skeletal metabolism. Here, we study the role of the vitamin K-dependent Gla-rich protein (GRP) in vascular and valvular calcification processes.

Approach And Results: Immunohistochemistry and quantitative polymerase chain reaction showed that GRP expression and accumulation are upregulated with calcification simultaneously with osteocalcin and matrix Gla protein (MGP).