Cardiac myoglobin deficit has evolved repeatedly in teleost fishes

Peer reviewedPublisher PD

Radial Velocity Observations and Light Curve Noise Modeling Confirm That Kepler-91b is a Giant Planet Orbiting a Giant Star

Kepler-91b is a rare example of a transiting hot Jupiter around a red giant star, providing the possibility to study the formation and composition of hot Jupiters under different conditions compared to main-sequence stars. However, the planetary nature of Kepler-91b, which was confirmed using phase-curve variations by Lillo-Box et al., was recently called into question based on a re-analysis of Kepler data. We have obtained ground-based radial velocity observations from the Hobby-Eberly Telescope and unambiguously confirm the planetary nature of Kepler-91b by simultaneously modeling the Kepler and radial velocity data. The star exhibits temporally correlated noise due to stellar granulation which we model as a Gaussian Process. We hypothesize that it is this noise component that led previous studies to suspect Kepler-91b to be a false positive. Our work confirms the conclusions presented by Lillo-Box et al. that Kepler-91b is a 0.73+/-0.13 Mjup planet orbiting a red giant star.Comment: Published in Ap

Genomic, evolutionary, and expression analyses of cee, an ancient gene involved in normal growth and development

AbstractThe cee (conserved edge expressed protein) gene was recently identified in a genome-wide screen to discover genes associated with myotube formation in fast muscle of pufferfish. Comparative genomic analyses indicate that cee arose some 1.6–1.8 billion years ago and is found as a single-copy gene in most eukaryotic genomes examined. The complexity of its structure varies from an intronless gene in yeast and tunicates to nine exons and eight introns in vertebrates. cee is particularly conserved among vertebrates and is located in a syntenic region within tetrapods and between teleosts and invertebrates. Low dN/dS ratios in the cee coding region (0.02–0.09) indicate that the Cee protein is under strong purifying selection. In Atlantic salmon, cee is expressed in the superficial layers of developing organs and tissues. These data, together with functional screens in yeast and Caenorhabditis elegans, indicate that cee has a hitherto uncharacterized role in normal growth and development

Evolution and Expression of Tissue Globins in Ray-Finned Fishes

We thank Professor Ian A. Johnston FRSE and Dr Daniel Garcia de la Serrana (School of Biology, University of St. Andrews) for providing tissues samples for African butterflyfish and spotted gar. We are grateful to Professor Peter W.H. Holland FRS (Department of Zoology, University of Oxford) for sharing sequence databases for Osteoglossiformes. We thank Professor Christopher J. Secombes (Institute of Biological and Environmental Sciences, University of Aberdeen) for gifting rainbow trout used in the study. Mr Ronald McKay contributed towards Pantodon molecular work during his undergraduate research. MDG is a PhD student funded by the BBSRC EASTBIO Doctoral Training Partnership (DTP) (BB/J01446X/1). The study received support from institutional funds within the University of Aberdeen and from an undergraduate Research Experience Placement scheme granted by the BBSRC EASTBIO DTP scheme.Peer reviewedPublisher PD

High-throughput proteomic profiling of the fish liver following bacterial infection

Abstract Background High-throughput proteomics was used to determine the role of the fish liver in defense responses to bacterial infection. This was done using a rainbow trout (Oncorhynchus mykiss) model following infection with Aeromonas salmonicida, the causative agent of furunculosis. The vertebrate liver has multifaceted functions in innate immunity, metabolism, and growth; we hypothesize this tissue serves a dual role in supporting host defense in parallel to metabolic adjustments that promote effective immune function. While past studies have reported mRNA responses to A. salmonicida in salmonids, the impact of bacterial infection on the liver proteome remains uncharacterized in fish. Results Rainbow trout were injected with A. salmonicida or PBS (control) and liver extracted 48 h later for analysis on a hybrid quadrupole-Orbitrap mass spectrometer. A label-free method was used for protein abundance profiling, which revealed a strong innate immune response along with evidence to support parallel rewiring of metabolic and growth systems. 3076 proteins were initially identified against all proteins (n = 71,293 RefSeq proteins) annotated in a single high-quality rainbow trout reference genome, of which 2433 were maintained for analysis post-quality filtering. Among the 2433 proteins, 109 showed significant differential abundance following A. salmonicida challenge, including many upregulated complement system and acute phase response proteins, in addition to molecules with putative functions that may support metabolic re-adjustments. We also identified novel expansions in the complement system due to gene and whole genome duplication events in salmonid evolutionary history, including eight C3 proteins showing differential changes in abundance. Conclusions This study provides the first high-throughput proteomic examination of the fish liver in response to bacterial challenge, revealing novel markers for the host defense response, and evidence of metabolic remodeling in conjunction with activation of innate immunity

GROWTH AND IMMUNITY CROSS-TALK IN RAINBOW TROUT: SUPRSSION OF THE INSULIN-LIKE GROWTH FACTOR SYSTEM DURING INFECTION

International audienceDuring disease and infection it is probable that growth is attenuated , the molecular pathways involved are poorly characterised. We postulated that the insulin - like growth factor (IGF) axis - a central endocrine governor of vertebrate growth - is repressed during infection to promote resource reallocation towards immunity. T his hypothesis was tested in rainbow trout ( Oncorhynchus mykiss ) challenged by Aeromonas salmonicida (AS), a Gram - negative bacterial pathogen, or viral hemorrhagic septicemia virus (VHSv) at hatch, first feeding and 3 weeks - post first - feeding. Quantitative transcriptional profiling was performed for genes encoding IGF hormones, all salmonid IGF - I receptor and IGF binding proteins , and a panel of marker genes for growth and immune status. Many IGF axis genes were developmentally upregulated in concert with g enes controlling muscle protein synthesis, recapturing the onset of complex growth regulation. There were also differences in the developmental response of the IGF axis to AS and VHSv, with the VHSv challenge causing strong downregulation of many genes. De spite this, IGFBP - 1A1 and IGFBP - 6A2 subtypes - each negative regulators of IGF signalling - were massively induced by AS and VHSv in striking correlation with host defence genes regulated by cytokine pathways. Follow up experiments demonstrated a massive u pregulation of IGFBP - 1A1 , IGFBP - 6A2 and proinflammatory cytokine genes , associated with large downregulation of genes encoding IGF hormones and IGF - I receptor in spleen and head kidney of rainbow trout challenged by a different bacterium, Yersinia ruckeri . Based on our findings, we propose a model where certain IGFBP subtypes are directly regulated by cytokine signalling pathways, allowing immediate modulation of growth and/or immune system phenotypes according to the level of activation of immunity. Our fi ndings provide new and comprehensive insights into cross - talk between conserved pathways regulating teleost growth, development and immunit