Lepisosteus

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Shaun P Collin - One of the best experts on this subject based on the ideXlab platform.

H B Collin - One of the best experts on this subject based on the ideXlab platform.

Robert M Dores - One of the best experts on this subject based on the ideXlab platform.

  • cloning of a gar Lepisosteus osseus gh cdna trends in actinopterygian gh structure
    Journal of Molecular Endocrinology, 1996
    Co-Authors: D A Rubin, Luciano E Marra, John H. Youson, Robert M Dores
    Abstract:

    : A cDNA containing the sequence of GH was cloned and sequenced from a pituitary cDNA library for the holostean fish Lepisosteus osseus (common name: gar). The gar GH cDNA contained an open reading frame of 633 nucleotides and a 3' untranslated region (including the terminal codon TAG) of 1058 nucleotides. The overall length of the gar GH cDNA including leader sequence, signal sequence, hormone sequence and 3' untranslated region was 1713 nucleotides. Thus, the gar GH cDNA is the largest vertebrate GH cDNA yet cloned. A comparison of GH sequences from ancient (holostean fishes-gar and bowfin; one chondrostean fish-the Russian sturgeon) and more modern (27 species of teleosts) members of class Actinopterygii indicate that members of this class have maintained many of the invariant residues deemed necessary for GH folding motifs (intramolecular relationships) observed in mammals.

  • detection of n acetylated forms of α msh and β endorphin in the intermediate pituitary of the holostean fishes Lepisosteus spatula Lepisosteus osseus and amia calva
    Peptides, 1994
    Co-Authors: Robert M Dores, Luciano E Marra, Heidi Keller, Yolanda White, John H. Youson
    Abstract:

    Abstract Acid extracts of the intermediate pituitaries of the gars, L. spatula and L. osseus , were fractionated by Sephadex G-50 column chromatography and analyzed by radioimmunoassay. This procedure revealed that immunoreactive forms of N- acetylated β-endorphin- and α-MSH-sized material were present in equimolar amounts and represented the major end products of the POMC biosynthetic pathway in these species. Cation-exchange chromatography indicated that multiple N- acetylated forms of β-endorphin were present in the intermediate pituitaries of the two species of gar, and that these forms differed in their net positive charge and in their apparent molecular weight. Reversed-phase HPLC analysis of the α-MSH-related material indicated that up to 90% of the total MSH in the pituitary of the gar was N- acetylated . Furthermore, the predominant form of α-MSH in both species of gar was N,O- diacetyl-ACTH (1–13)- NH 2 . Nearly identical results were obtained following the analysis of α-MSH-related peptides in the intermediate pituitary of the bowfin, A. calva . The pattern of posttranslational processing of POMC observed in the intermediate pituitaries of holostean fishes is very similar to the processing events observed in lungfishes, turtles, and mammals; hence, the processing of POMC has been remarkably conserved during vertebrate evolution.

  • the phylogeny of met enkephalin and leu enkephalin studies on the holostean fish Lepisosteus platyrhincus and the australian lungfish neoceratodus forsteri
    General and Comparative Endocrinology, 1991
    Co-Authors: Robert M Dores, Jean M P Joss, Lorraine K Mcdonald
    Abstract:

    Abstract Acid extracts of the brain of the holostean fish Lepisosteus platyrhincus and the forebrain of the dipnoan fish Neoceratodus forsteri were separately fractionated by Sephadex G-50 column chromatography. For both species, Met-enkephalin-related immunoreactivity was detected coeluting with the total volume internal standard. Higher-molecular-weight Met-enkephalin-containing immunoreactive peaks were not detected in these chromatographs. Furthermore, immunoreactive forms with antigenic determinants identical to mammalian dynorphin A(1–17), dynorphin A(1–8), α-neo-endorphin, or dynorphin B(1–13) were not detected in either species. Reverse-phase HPLC analysis of enkephalin-sized immunoreactive material indicated the presence of authentic Met-enkephalin and Leu-enkephalin in the extracts of both species. In the brain of L. platyrhincus the molar ratio of Met-enkephalin to Leu-enkephalin was approximately 3:1, whereas, the molar ratio of these enkephalins in the forebrain of N. forsteri was approximately 14:1. C-terminally extended forms of Met-enkephalin were also detected in the extracts of both species. These results suggest that the ancestral proenkephalin gene of both actinopterygian and sarcopterygian fish contained both the Met-enkephalin and Leu-enkephalin sequences.

  • immunocytochemical location of pituitary cells containing acth α msh and β endorphin in acipenser transmontanus Lepisosteus spatula and amia calva
    General and Comparative Endocrinology, 1990
    Co-Authors: Jean M P Joss, Robert M Dores, Joe W Crim, Mandy Beshaw
    Abstract:

    Abstract This immunocytochemical study of the pituitaries of the primitive actinopterygians, Acipenser transmontanus, Lepisosteus spatula , and Amia calva , showed a strict delineation between the hormonal fragments of proopiomelanocorticotropin (POMC) produced by corticotropes of the pars distalis and the melanotropes of the pars intermedia. Corticotropes were immunoreactive only for ACTH and not to either of the further degradation products, α-MSH or β-endorphin. Melanotropes were shown to be immunoreactive to all three antisera but it is argued that immunoreactivity of melanotropes to ACTH antiserum is due to that antiserum's cross-reactivity with the cleavage product corticotropin-like intermediate peptide. The PAS positivity of both the corticotropes and the melanotropes of all three primitive fish argues for an ancient origin of a carbohydrate component of POMC and for its loss or reduction in teleosts where these cells are PAS negative.

Barry H Collin - One of the best experts on this subject based on the ideXlab platform.

John H. Postlethwait - One of the best experts on this subject based on the ideXlab platform.

  • the molecular evolution of circadian clock genes in spotted gar Lepisosteus oculatus
    Genes, 2019
    Co-Authors: Moli Huang, John H. Postlethwait, Jian Huang, Jiguang Zhang, Han Wang
    Abstract:

    Circadian rhythms are biological rhythms with a period of approximately 24 h. While canonical circadian clock genes and their regulatory mechanisms appear highly conserved, the evolution of clock gene families is still unclear due to several rounds of whole genome duplication in vertebrates. The spotted gar (Lepisosteus oculatus), as a non-teleost ray-finned fish, represents a fish lineage that diverged before the teleost genome duplication (TGD), providing an outgroup for exploring the evolutionary mechanisms of circadian clocks after whole-genome duplication. In this study, we interrogated the spotted gar draft genome sequences and found that spotted gar contains 26 circadian clock genes from 11 families. Phylogenetic analysis showed that 9 of these 11 spotted gar circadian clock gene families have the same number of genes as humans, while the members of the nfil3 and cry families are different between spotted gar and humans. Using phylogenetic and syntenic analyses, we found that nfil3-1 is conserved in vertebrates, while nfil3-2 and nfil3-3 are maintained in spotted gar, teleost fish, amphibians, and reptiles, but not in mammals. Following the two-round vertebrate genome duplication (VGD), spotted gar retained cry1a, cry1b, and cry2, and cry3 is retained in spotted gar, teleost fish, turtles, and birds, but not in mammals. We hypothesize that duplication of core clock genes, such as (nfil3 and cry), likely facilitated diversification of circadian regulatory mechanisms in teleost fish. We also found that the transcription factor binding element (Ahr::Arnt) is retained only in one of the per1 or per2 duplicated paralogs derived from the TGD in the teleost fish, implicating possible subfuctionalization cases. Together, these findings help decipher the repertoires of the spotted gar’s circadian system and shed light on how the vertebrate circadian clock systems have evolved.

  • skeletal development in the heterocercal caudal fin of spotted gar Lepisosteus oculatus and other lepisosteiformes
    Developmental Dynamics, 2018
    Co-Authors: Thomas Desvignes, Andrew Carey, Ingo Braasch, Trevor Enright, John H. Postlethwait
    Abstract:

    BACKGROUND: The caudal fin of actinopterygians experienced substantial morphological changes during evolution. In basal actinopterygians, the caudal fin skeleton supports an asymmetrical heterocercal caudal fin, while most teleosts have a symmetrical homocercal caudal fin. The transition from the ancestral heterocercal form to the derived homocercal caudal fin remains poorly understood. Few developmental studies provide an understanding of derived and ancestral characters among basal actinopterygians. To fill this gap, we examined the development of the caudal fin of spotted gar Lepisosteus oculatus, one of only eight living species of Holostei, the sister group to the teleosts. RESULTS: Our observations of animals from fertilization to more than a year old provide the most detailed description of the development of caudal fin skeletal elements in any Holostean species. We observed two different types of distal caudal radials replacing two transient plates of connective tissue, identifying two hypaxial ensembles separated by a space between hypurals 2 and 3. These features have not been described in any gar species, but can be observed in other gar species, and thus represent anatomical structures common to lepisosteiformes. CONCLUSIONS: The present work highlights the power and importance of ontogenic studies and provides bases for future evolutionary and morphological investigations on actinopterygians fins. Developmental Dynamics 247:724-740, 2018. © 2018 Wiley Periodicals, Inc.

  • Skeletal development in the heterocercal caudal fin of spotted gar (Lepisosteus oculatus) and other Lepisosteiformes
    Developmental Dynamics, 2018
    Co-Authors: Thomas Desvignes, Andrew Carey, Ingo Braasch, Trevor Enright, John H. Postlethwait
    Abstract:

    Background The caudal fin of actinopterygians experienced substantial morphological changes during evolution. In basal actinopterygians, the caudal fin skeleton supports an asymmetrical heterocercal caudal fin, while most teleosts have a symmetrical homocercal caudal fin. The transition from the ancestral heterocercal form to the derived homocercal caudal fin remains poorly understood. Few developmental studies provide an understanding of derived and ancestral characters among basal actinopterygians. To fill this gap, we examined the development of the caudal fin of spotted gar Lepisosteus oculatus, one of only eight living species of Holostei, the sister group to the teleosts.

Related terms

  • garfish lepisosteus platyrhincus ginglymodi
  • florida garfish lepisosteus platyrhincus
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