861 research outputs found

    A phylogenomic perspective on the radiation of ray-finned fishes based upon targeted sequencing of ultraconserved elements

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    Ray-finned fishes constitute the dominant radiation of vertebrates with over 30,000 species. Although molecular phylogenetics has begun to disentangle major evolutionary relationships within this vast section of the Tree of Life, there is no widely available approach for efficiently collecting phylogenomic data within fishes, leaving much of the enormous potential of massively parallel sequencing technologies for resolving major radiations in ray-finned fishes unrealized. Here, we provide a genomic perspective on longstanding questions regarding the diversification of major groups of ray-finned fishes through targeted enrichment of ultraconserved nuclear DNA elements (UCEs) and their flanking sequence. Our workflow efficiently and economically generates data sets that are orders of magnitude larger than those produced by traditional approaches and is well-suited to working with museum specimens. Analysis of the UCE data set recovers a well-supported phylogeny at both shallow and deep time-scales that supports a monophyletic relationship between Amia and Lepisosteus (Holostei) and reveals elopomorphs and then osteoglossomorphs to be the earliest diverging teleost lineages. Divergence time estimation based upon 14 fossil calibrations reveals that crown teleosts appeared ~270 Ma at the end of the Permian and that elopomorphs, osteoglossomorphs, ostarioclupeomorphs, and euteleosts diverged from one another by 205 Ma during the Triassic. Our approach additionally reveals that sequence capture of UCE regions and their flanking sequence offers enormous potential for resolving phylogenetic relationships within ray-finned fishes

    Diversity of immunoglobulin light chain genes in non-teleost ray-finned fish uncovers IgL subdivision into five ancient isotypes

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    <p>The aim of this study was to fill important gaps in the evolutionary history of immunoglobulins by examining the structure and diversity of IgL genes in non-teleost ray-finned fish. First, based on the bioinformatic analysis of recent transcriptomic and genomic resources, we experimentally characterized the IgL genes in the chondrostean fish, Acipenser ruthenus (sterlet). We show that this species has three loci encoding IgL kappa-like chains with a translocon-type gene organization and a single VJC cluster, encoding homogeneous lambda-like light chain. In addition, sterlet possesses sigma-like VL and J-CL genes, which are transcribed separately and both encode protein products with cleavable leader peptides. The Acipenseriformes IgL dataset was extended by the sequences mined in the databases of species belonging to other non-teleost lineages of ray-finned fish: Holostei and Polypteriformes. Inclusion of these new data into phylogenetic analysis showed a clear subdivision of IgL chains into five groups. The isotype described previously as the teleostean IgL lambda turned out to be a kappa and lambda chain paralog that emerged before the radiation of ray-finned fish. We designate this isotype as lambda-2. The phylogeny also showed that sigma-2 IgL chains initially regarded as specific for cartilaginous fish are present in holosteans, polypterids, and even in turtles. We conclude that there were five ancient IgL isotypes, which evolved differentially in various lineages of jawed vertebrates.</p

    Tetraodon genome confirms Takifugu findings : most fish are ancient polyploids

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    An evolutionary hypothesis suggested by studies of the genome of the tiger pufferfish Takifugu rubripes has now been confirmed by comparison with the genome of a close relative, the spotted green pufferfish Tetraodon nigroviridis. Ray-finned fish underwent a whole-genome duplication some 350 million years ago that might explain their evolutionary success

    Biological reviews of important Cambodian fish species, based on fishbase 2004 Volume 1

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    This document is a review of all the information published worldwide about ten fish species that contribute significantly to Cambodian fishery resources.Freshwater fish, Cambodia, Channa striata, Channa micropeltes, Barbonymus altus, Barbonymus gonionotus, Cyclocheilichthys apogon, Cyclocheilichthys enoplos, Henicorhynchus lineatus, Henicorhynchus siamensis, Pangasius hypophthalmus, Pangasius djambal

    Biological reviews of important Cambodian fish species, based on fishbase 2004 volume 2

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    This document is a review of all the information published worldwide about ten fish species that contribute significantly to Cambodian fishery resources.Freshwater fish, Cambodia, Pangasius larnaudii, Clarias batrachus, Cirrhinus microlepis, Leptobarbus hoevenii, Thynnichthys thynnoides, Trichogaster microlepis, Trichogaster pectoralis, Anabas testudineus, Boesemania microlepis, Oxyeleotris marmorata

    Davidson Seamount Taxonomic Guide

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    Davidson Seamount is one of the largest seamounts in U.S. waters and the first to be characterized as a “seamount.” In 2002 and 2006, the Monterey Bay National Marine Sanctuary (MBNMS) led two multi-institutional expeditions to characterize the geology and natural history of Davidson Seamount. Results from these expeditions to Davidson Seamount are adding to the scientific knowledge of seamounts, including the discovery of new species. In November 2008, the MBNMS boundary was expanded to include the Davidson Seamount. In addition, a management plan for Davidson Seamount was created to develop resource protection, education, and research strategies for the area. The purpose of this taxonomic guide is to create an inventory of benthic and mid-water organisms observed at the Davidson Seamount to provide a baseline taxonomic characterization. At least 237 taxa were observed and are presented in this guide; including 15 new or undescribed species (8 sponges, 3 corals, 1 ctenophore, 1 nudibranch, 1 polychaete, 1 tunicate) recently or currently being described by taxonomic experts. This is the first taxonomic guide to Davidson Seamount, and is intended to be revised in the future as we learn more about the seamount and the organisms that live there. (PDF has 145 pages.

    The Presence of Transposable Elements in Actinopterygii, The Ray Finned Fish

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    Purpose: My project developed after I was introduced to the idea of horizontal gene transfer in various species. I wanted to further understand one of the largest known mechanisms of horizontal gene transfer, SINE and LINE elements. This project is centered around the analysis of Transposable Elements in various Actinopterygii populations. Transposable Elements are extremely common in The Ray Finned Fish, however analysis of their frequency and position has yet to be done in a majority of the class. I plan to identify their presence in three groups of Ray Finned Fish – Atlantic Killifish, African Cichlids, and Guppies – to analyze their impact on the evolution of each species

    Histological atlas of Florida Surgeonfish (Acanthuridae)

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    This histological atlas focuses on A. coeruleus and includes major organs and tissues. Particularly note the stomach tissues of both species, which illustrate the difference in digestive strategies of the Carribbean Acanthurids. Acanthurus chirurgus was intentionally left out of this atlas, as its tissues are identical to those of ?A. bahianus(PDF has 22 pages
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