Caird Rexroad - Academia.edu (original) (raw)

Papers by Caird Rexroad

BMC genomics, 2005

Microarray technologies are rapidly becoming available for new species including teleost fishes. ... more Microarray technologies are rapidly becoming available for new species including teleost fishes. We constructed a rainbow trout cDNA microarray targeted at the identification of genes which are differentially expressed in response to environmental stressors. This platform included clones from normalized and subtracted libraries and genes selected through functional annotation. Present study focused on time-course comparisons of stress responses in the brain and kidney and the identification of a set of genes which are diagnostic for stress response. Fish were stressed with handling and samples were collected 1, 3 and 5 days after the first exposure. Gene expression profiles were analysed in terms of Gene Ontology categories. Stress affected different functional groups of genes in the tissues studied. Mitochondria, extracellular matrix and endopeptidases (especially collagenases) were the major targets in kidney. Stress response in brain was characterized with dramatic temporal alter...

Liu/Next Generation Sequencing and Whole Genome Selection in Aquaculture, 2010

... with growth in the Kuruma prawn, Marsupenaeus japonicus, and identi-fication of a candidate g... more ... with growth in the Kuruma prawn, Marsupenaeus japonicus, and identi-fication of a candidate gene ... Physical and genetic mapping of the rainbow trout major histo-compatibility regions: Evidence for duplication ... Genome-wide association study of growth in cross-bred beef cattle ...

Journal of Experimental Biology, 2004

BMC Genomics, 2011

Fish under intensive culture conditions are exposed to a variety of acute and chronic stressors, ... more Fish under intensive culture conditions are exposed to a variety of acute and chronic stressors, including high rearing densities, sub-optimal water quality, and severe thermal fluctuations. Such stressors are inherent in aquaculture production and can induce physiological responses with adverse effects on traits important to producers and consumers, including those associated with growth, nutrition, reproduction, immune response, and fillet quality. Understanding and monitoring the biological mechanisms underlying stress responses will facilitate alleviating their negative effects through selective breeding and changes in management practices, resulting in improved animal welfare and production efficiency. Physiological responses to five treatments associated with stress were characterized by measuring plasma lysozyme activity, glucose, lactate, chloride, and cortisol concentrations, in addition to stress-associated transcripts by quantitative PCR. Results indicate that the fish had significant stressor-specific changes in their physiological conditions. Sequencing of a pooled normalized transcriptome library created from gill, brain, liver, spleen, kidney and muscle RNA of control and stressed fish produced 3,160,306 expressed sequence tags which were assembled and annotated. SNP discovery resulted in identification of ~58,000 putative single nucleotide polymorphisms including 24,479 which were predicted to fall within exons. Of these, 4907 were predicted to occupy the first position of a codon and 4110 the second, increasing the probability to impact amino acid sequence variation and potentially gene function. We have generated and characterized a reference transcriptome for rainbow trout that represents multiple tissues responding to multiple stressors common to aquaculture production environments. This resource compliments existing public transcriptome data and will facilitate approaches aiming to evaluate gene expression associated with stress in this species.

Biochemical and Biophysical Research Communications, 2004

Animal Biotechnology, 2003

Rainbow trout (Oncorhynchus mykiss) have two types of lysozyme. Type II lysozyme differs from typ... more Rainbow trout (Oncorhynchus mykiss) have two types of lysozyme. Type II lysozyme differs from type I by only one amino acid, but only type II lysozyme has significant bactericidal activity. Due to this novel antibacterial property, lysozyme type II appears to be a candidate gene for enhancing disease resistance in fish as well as livestock species. Using polymerase chain reaction the lysozyme type II gene was amplified from genomic DNA isolated from rainbow trout. Two amplified fragments of 2041 and 2589 bp were observed. Sequencing revealed both amplicons were lysozyme genes having nearly identical nucleotide sequences, except the longer fragment has 548 base pairs inserted in intron 2 at nucleotide position 513 and a few point mutations within intron 2. Both versions of trout lysozyme type II gene were comprised of four exons and three introns. We also demonstrated that trout lysozyme is most likely encoded by these two different genes.

Biology of Reproduction, Jul 1, 2011

Mammalian Genome, Feb 1, 1997

... We had previously identified a polymorphism in this gene and mapped it by linkage analysis in... more ... We had previously identified a polymorphism in this gene and mapped it by linkage analysis in an International Bovine Reference Panel (IBRP; Barendse et al. 1997). Its location on this map is indistinguishable from the microsatellite, IOBT34, 6 cM proximal to URB59. ...

Animal Genetics, Apr 1, 2003

Http Dx Doi Org 10 1577 T02 086, Jan 9, 2011

ABSTRACT

Comparative Biochemistry and Physiology Part B Biochemistry and Molecular Biology, Jan 31, 2005

Calpains are calcium regulated proteases involved in cellular functions that include muscle prote... more Calpains are calcium regulated proteases involved in cellular functions that include muscle proteolysis both ante- and postmortem. Here, we describe the molecular characterization of the rainbow trout catalytic subunits of the μ- and m-calpains, respectively. The cDNA sequence for Capn1 encodes a protein of 704 amino acids with a calculated molecular mass of 79.9 kDa. The amino acid sequence shows 66% and 86% identity with the mouse and zebrafish Capn1, respectively. The Capn2 cDNA codes for a protein consisting of 701 amino acid residues with a calculated molecular mass of 78.2 kDa. The protein shows 65% amino acid sequence identity with the mouse and chicken Capn2. The two isozymes of rainbow trout have the characteristic domains: I (propeptide), II (cysteine catalytic site), III (electrostatic switch), and IV (contains five EF-hands). Because starvation induces muscle wasting, the hypothesis of this study was that starvation could affect regulation of the calpain system in muscle. Starvation of rainbow trout fingerlings (15–20 g) for 35 days stimulated the expression of Capn1 (2.2-fold increase, P<0.01), Capn2 (6.0-fold increase, P<0.01), and calpastatins (1.6-fold increase, P<0.05) as measured by quantitative real-time RT-PCR. The mRNA changes led to a 1.23-fold increase in the calpain catalytic activity. The results suggest a potential role of calpains in protein mobilization as a source of energy under fasting condition.

Biology of Reproduction, Nov 1, 2010