The steroidogenic acute regulatory protein (StAR), a member of the StAR-related lipid transfer domain (START) family, is critical to regulated steroidogenesis in vertebrates. We have isolated a cDNA encoding StAR from a well-studied model of teleost physiology, the Atlantic croaker Micropogonias undulatus. This cDNA (1204 nucleotides total length) contains an open reading frame of 858 nucleotides encoding a protein of 286 amino acids. Molecular phylogenetic analysis indicates the putative Atlantic croaker StAR protein is more closely related to StAR proteins (62-85% identity) than to the related START protein MLN-64 (28-31% identity). Green monkey kidney cells (COS-1) cotransfected with Atlantic croaker StAR and human cholesterol side chain cleavage (SCC) expression constructs are able to produce significantly more pregnenolone than cells transfected with SCC alone. StAR mRNA is detected in the Atlantic croaker head kidney by reverse transcriptase-polymerase chain reaction (RT-PCR) and in the kidney and hypothalamus in some individuals. Gonadal StAR gene expression is below the level of detection by RT-PCR in most individuals, but can be detected using fluorescent probes in quantitative RT-PCR. StAR mRNA is not detected in the Atlantic croaker brain. Six hour in vitro treatment of Atlantic croaker ovarian follicles with human chorionic gonadotropin (hCG) is insufficient to significantly alter StAR mRNA levels; however, 24 h hCG treatment induces StAR mRNA levels 17-fold over untreated controls. Neither 6 nor 24 h treatment with hCG significantly alters StAR mRNA levels in Atlantic croaker testicular minces. Likewise, 6h in vitro treatment with estradiol, testosterone or the maturation-inducing steroid 17,20beta,21-trihydroxy-4-pregnen-3-one is without effect on gonadal StAR mRNA levels.
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http://dx.doi.org/10.1016/j.ygcen.2006.11.011 | DOI Listing |
Biology (Basel)
January 2025
Fish Health Division, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria.
A new species of (Ceratomyxidae, Myxosporea) was found infecting the gall bladder of the Argentine croaker Berg 1895 (Sciaenidae, Perciformes) from the Argentine sea. Using an integrative taxonomic approach that combines morphological, bioecological, and molecular analyses, we provide evidence that clearly differentiates this species from known taxa and formally describe as a new species. This study is the first to apply landmark-based geometric morphometrics (GM) in myxozoan research, providing a detailed analysis of conspecific morphometric variation of ceratomyxid myxospores, examining their natural variation within and among different ceratomyxids infecting the gall bladder of .
View Article and Find Full Text PDFActa Parasitol
January 2025
Departamento de Parasitologia Animal, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ, 23897-000, Brazil.
Introduction: Copepods of the genus Colobomatus Hesse, 1873 are parasites associated with subcutaneous spaces of marine fish. To date, around 76 species of the genus have been described in marine ecosystems, but few species have been recorded in the South Atlantic Ocean.
Methods: One hundred and eight specimens of Co.
Mol Biol Rep
January 2025
School of Ocean Science and Engineering, The University of Southern Mississippi, Ocean Springs, MS, 39564, USA.
Background: The gray snapper (Lutjanus griseus) is a marine reef fish commonly found in coastal and shelf waters of the tropical and subtropical western Atlantic Ocean. In this work, a draft reference genome was developed to support population genomic studies of gray snapper needed to assist with conservation and fisheries management efforts.
Methods And Results: Hybrid assembly of PacBio and Illumina sequencing reads yielded a 1,003,098,032 bp reference across 2039 scaffolds with N50 and L50 values of 1,691,591 bp and 163 scaffolds, respectively.
Sci Rep
January 2025
Environment and Sustainability Institute, University of Exeter, Penryn, TR10 9FE, UK.
Understanding the spatial ecology of commercially exploited species is vital for their conservation. Atlantic bluefin tuna (Thunnus thynnus, ABT) are increasingly observed in northeast Atlantic waters, yet knowledge of these individuals' spatial ecology remains limited. We investigate the horizontal and vertical habitat use of ABT (158 to 241 cm curved fork length; CFL) tracked from waters off the United Kingdom (UK) using pop-up satellite archival tags (n = 63).
View Article and Find Full Text PDFThe Atlantic wolffish (Anarhichas lupus) is a cold-water fish with potential for aquaculture diversification. To unveil the mechanisms underlying the compromised growth in Atlantic wolffish when reared at higher temperatures, we investigated the relationship between temperature, growth rate, aerobic capacity, stress biomarkers, and gut barrier function. Juveniles acclimated to 10°C were maintained at 10°C (control) or exposed to 15°C for either 24 h (acute exposure) or 50 days (chronic exposure).
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