Publications

Allozymes continue to be useful as genetic markers in a variety of studies; however, their utility often hinges on the selective neutrality of the allelic variation. Our study tested for neutrality between the two most common alleles (*100 and *110) at the cytosol nonspecific dipeptidase locus (PEPA-1*) in steelhead Oncorhynchus mykiss from Dworshak National Fish Hatchery in Idaho. We tested for d

Host-parasite interactions influence host population growth, host evolution and parasite success. We examined the interactions among Myxobolus cerebralis, the parasite that causes salmonid whirling disease, and resistant and susceptible strains of the oligochaete host Tubifex tubifex. Strains of T. tubifex with diverse genotypes often coexist in nature and have variable susceptibilities to M. cere

A simple, inexpensive apparatus (embryo incubation unit [EIU]) was developed and used to assess the relationship between sediment cover (Kootenai River sediments, 97% by weight in the 0.83-mm- to 1.0-mm-diameter range) and survival of white sturgeon Acipenser transmontanus embryos in the laboratory. An apparatus-testing trial assessed the effects of two sediment depths (5 and 20 mm), three EIU ven

Tapasin (TAPBP) is a key member of MHC class Ia antigen-loading complexes, bridging the class Ia molecule to the transporter associated with antigen presentation (TAP). As part of an ongoing study of MHC genomics in rainbow trout, we have identified two rainbow trout TAPBP genes (Onmy-TAPBP.a and .b) and a similar but distinct TAPBP-related gene (Onmy-TAPBP-R) that had previously only been describ

Renibacterium salmoninarum, a gram-positive diplococcobacillus that causes bacterial kidney disease among salmon and trout, has two chromosomal loci encoding the major soluble antigen (msa) gene. Because the MSA protein is widely suspected to be an important virulence factor, we used insertion-duplication mutagenesis to generate disruptions of either the msa1 or msa2 gene. Surprisingly, expression

T cell activation requires both specific recognition of the peptide-MHC complex by the TCR and additional signals delivered by costimulatory receptors. We have identified rainbow trout sequences similar to CD28 (rbtCD28) and CTLA4 (rbtCTLA4). rbtCD28 and rbtCTLA4 are composed of an extracellular Ig-superfamily V domain, a transmembrane region, and a cytoplasmic tail. The presence of a conserved li

The effectiveness of morphometric and meristic characteristics for taxonomic discrimination of Lampetra tridentata and L. richardsoni (Petromyzonidae) during embryological, prolarval, and early larval stages (i.e., age class 1) were examined. Mean chorion diameter increased with time from fertilization to hatch and was significantly greater for L. tridentata than for L. richardsoni at 1, 8, and 15

Electromyogram (EMG) radiotelemetry was used to estimate the swim speeds of spring Chinook salmon Oncorhynchus tshawytscha migrating upstream past a Columbia River dam. Electrodes from EMG transmitters were surgically implanted in the red muscle of fish captured at Bonneville Dam, and output from the tags was calibrated to defined swim speeds for each fish in a tunnel respirometer. The fish were t

The T cell coreceptor CD4 is a transmembrane glycoprotein belonging to the Ig superfamily and is essential for cell-mediated immunity. Two different genes were identified in rainbow trout that resemble mammalian CD4. One (trout CD4) encodes four extracellular Ig domains reminiscent off mammalian CD4, whereas the other (CD4REL) codes for two Ig domains. Structural motifs within the amino acid seque

The occurrence and distribution of culturable fungi in Taylor Valley, Antarctica was assessed in terms of soil habitat. Soil transects throughout the valley revealed differential habitat utilization between filamentous and non-filamentous (yeast and yeast-like) fungi. In addition, there were significant differences in species distribution patterns with respect to soil pH, moisture, distance from m

Renibacterium salmoninarum is an important salmonid pathogen that is difficult to culture. We developed and assessed a real-time, quantitative, polymerase chain reaction (qPCR) assay for the detection and enumeration of R. salmoninarum. The qPCR is based on TaqMan technology and amplifies a 69-base pair (bp) region of the gene encoding the major soluble antigen (MSA) of R. salmoninarum. The qPCR a

A highly efficacious DNA vaccine against a fish rhabdovirus, infectious hematopoietic necrosis virus (IHNV), was mutated to introduce two stop codons to prevent glycoprotein translation while maintaining the plasmid DNA integrity and RNA transcription ability. The mutated plasmid vaccine, denoted pIHNw-G2stop, when injected intramuscularly into fish at high doses, lacked detectable glycoprotein ex