Publications by authors named "Giles W Goetz"

Concepts of evolutionary biology suggest that morphological change may occur by rare punctual but rather large changes, or by more steady and gradual transformations. It can therefore be asked whether genetic changes underlying morphological, physiological, and/or behavioral innovations during evolution occur in a punctual manner, whereby a single mutational event has prominent phenotypic consequences, or if many consecutive alterations in the DNA over longer time periods lead to phenotypic divergence. In the marine teleost, sablefish (), complementary genomic and genetic studies led to the identification of a sex locus on the Y Chromosome.

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Cardiac remodeling results from both physiological and pathological stimuli. Compared with mammalian hearts, fish hearts show a broader array of remodeling changes in response to environmental influences, providing exceptional models for dissecting the molecular and cellular bases of cardiac remodeling. We recently characterized a form of pathological remodeling in juvenile pink salmon () in response to crude oil exposure during embryonic cardiogenesis.

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Genetic selection is often implicated as the underlying cause of heritable phenotypic differences between hatchery and wild populations of steelhead trout () that also differ in lifetime fitness. Developmental plasticity, which can also affect fitness, may be mediated by epigenetic mechanisms such as DNA methylation. Our previous study identified significant differences in DNA methylation between adult hatchery- and natural-origin steelhead from the same population that could not be distinguished by DNA sequence variation.

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Many teleost fishes exhibit sequential hermaphroditism, where male or female gonads develop first and later undergo sex change. Model sex change species are characterized by social hierarchies and coloration changes, which enable experimental manipulations to better understand these processes. However, other species such as the protogynous black sea bass (Centropristis striata) do not exhibit these characteristics and instead receive research attention due to their importance in fisheries or aquaculture.

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While the goal of most conservation hatchery programs is to produce fish that are genetically and phenotypically indistinguishable from the wild stocks they aim to restore, there is considerable evidence that salmon and steelhead reared in hatcheries differ from wild fish in phenotypic traits related to fitness. Some evidence suggests that these phenotypic differences have a genetic basis (, domestication selection) but another likely mechanism that remains largely unexplored is that differences between hatchery and wild populations arise as a result of environmentally-induced heritable epigenetic change. As a first step toward understanding the potential contribution of these two possible mechanisms, we describe genetic and epigenetic variation in hatchery and natural-origin adult steelhead, , from the Methow River, WA.

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Crude oil spills are a worldwide ocean conservation threat. Fish are particularly vulnerable to the oiling of spawning habitats, and crude oil causes severe abnormalities in embryos and larvae. However, the underlying mechanisms for these developmental defects are not well understood.

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Article Synopsis
  • Research has highlighted the limited understanding of how endocrine disrupting chemicals (EDCs), particularly estrogens like 17α-ethynylestradiol (EE2), affect the pituitary gland, which plays a crucial role in reproduction in teleost fish.
  • A study on sub-adult coho salmon showed that exposure to EE2 significantly altered the pituitary transcriptome, with hundreds of genes being differentially expressed after 1 and 6 weeks, including key hormones such as luteinizing hormone and follicle-stimulating hormone.
  • The affected genes were linked to various biological pathways, such as circadian rhythm and gonadotropin signaling, indicating that EE2 may disrupt the timing of reproductive processes in fish.
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The effects of dietary 17beta-estradiol (E(2)) on growth and liver transcriptomics were investigated in the yellow perch (Perca flavescens). After a 3-mo treatment, E(2) significantly stimulated an increase in length and weight of juvenile male and female perch relative to control animals. The increase was significantly greater in females compared with males.

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The spatial and temporal variability of bacterial communities were determined for the nearshore waters of Lake Michigan, an oligotrophic freshwater inland sea. A freshwater estuary and nearshore sites were compared six times during 2006 using denaturing gradient gel electrophoresis (DGGE). Bacterial composition clustered by individual site and date rather than by depth.

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This study investigated the occurrence and diversity of Bacteroidales fecal bacteria in gulls residing in the Great Lakes region. Members of this bacterial order have been widely employed as human and bovine host-specific markers of fecal pollution; however, few studies have focused on gulls, which can be a major source of fecal indicator bacteria and pathogens at beaches. We found a low but consistent occurrence of Bacteroidales in gulls at five beaches in three different counties spanning the Wisconsin shoreline of Lake Michigan.

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Pathogens can be distinctively recognized by the cells of the immune system through interactions between the Pathogen-Associated Molecular Patterns (PAMPs) that they produce and the innate immune receptors of leukocytes. The present paper reports on the PAMP-modulated expression of a group of genes expressed in trout macrophages. The genes were identified in subtracted libraries from lipopolysaccharide (LPS)-stimulated macrophages and their expression was analyzed using quantitative real time PCR following stimulation of the cells with E.

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