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Item Host tracking and photosensitivity in Chaetogaster limnaei limnaei (Oligochaeta)(1992) Shaw, RossChaetogaster limnaei limnaei were separated from host snails (Physa skinneri) for increasing periods of time. The oligochaetes responded to a snail's slime trail by increased activity and distance moved along the slime trail. These responses increased with increasing periods of separation from the snail. When exposed to a directional light source, C. l. limnaei displayed an initial positive phototactic response. Movement towards light from the same direction decreased significantly in a second 4-h period, but movement towards light from a different direction was equivalent to the initial response, suggesting the response was an initial one to a change in light.Item Abundance of the parasitic copepod Caligus elongatus on wild pollock near commercial salmonid net-pens(1996) Shaw, Ross; Opitz, M.Between July and December 1993, wild pollock Pollachius virens collected near salmonid net‐pens on the Atlantic coast of Maine in the United States were examined for parasitic copepods of the family Caligidae to determine the role of pollock as host reservoirs. Only Caligus elongatus was detected on 1,456 pollock sampled. Most pollock (97.39%) had two or fewer sea lice per fish. A maximum prevalence (percent of fish infested) of 50%, an abundance (average number per fish) of 0.9, and an intensity (average number per infested fish) of L79 were recorded. Only one larval C. elongatus was found. No seasonal or geographic trends in infestation statistics were observed.Item Three subsets of genes whose tissue specific expression is sex and age-dependent can be identified within the rat alpha(2u)-globulin family(1997) Wang, Kathy S.; McFadyen, David A.; Locke, John; Hodgetts, Ross B.The rat α2u‐globulins are encoded by a multigene family whose 20–25 members are subjected to multihormonal regulation that is dependent upon the sex of the animal, the developmental stage and the tissue being examined. Using RT‐PCR and diagnostic restriction analysis of the products, we have examined the specificity of the expression of different members of the gene family. All family members can be classified into three subsets, depending on how the amplified cDNA responds to digestion with ApaLI, SstI and VspI. Subset A contains the restriction sites for both ApaLI and SstI but not VspI and typifies the genes expressed in the salivary glands of both mature and juvenile animals of both sexes, where it is the only subset expressed. This subset of genes also accounts for all the transcripts observed in the kidneys and mammary glands of juvenile males. Although subset A was represented in the transcript populations of all the other tissues examined, its proportion relative to the total varied greatly. The two other subsets were subset V, which contains only the restriction site for VspI, and subset N, which lacks all three restriction sites. In all the other tissues examined, two or all three of the subsets were expressed, usually in a manner that was unique to the sex and age of the tissue in question. The proportion of each of the three α2u‐globulin subsets in the α2u‐globulin gene family was determined by quantitation of the restriction products of amplified genomic DNA. Interestingly, the most prevalent subset in the genome (N) has the most limited tissue expression pattern, but is found in liver and preputial glands, the tissues expressing the most substantial quantities of α2u‐globulin. These results indicate the complexity of the regulation of the α2u‐globulins and point to the necessity for gene specific analyses if the expression of the family is to be understood in molecular terms.Item A new species of Loma (Microsporea) in Shiner perch (Cymatogaster aggregata)(1997) Shaw, Ross W.; Kent, Michael L.; Docker, Margaret F.; Brown, A. M.; Devlin, Robert H.; Adamson, Martin L.Loma embiotocia n. sp. is described from the gills of shiner perch (Cymatogaster aggregata) from waters off Vancouver Island, British Columbia, Canada. Highest prevalence at a site was 15% and greatest intensity was 583 xenomas per fish. Xenomas averaged 0.13 mm in diameter (0.06-0.16 mm) and contained ovoid spores 4.8 x 2.6 (4.0-5.0 x 2.0-3.0) µm. Sporogonic stages were dispersed throughout the xenomas. The xenoma wall was smooth lacking invaginations into the cytoplasm; sporoblasts were not highly vacuolated, and the sporophorous vesicle formed before sporogony. In addition to differences in host and geographic location the new species is distinguished from Loma salmonae, the only other species in the genus known from British Columbia, by its internal transcribed spacer (ITS) ribosomal DNA sequence.Item Infection of Aulorhynchus flavidus (Gill) (Osteichthyes: Gasterosteiformes) by Kudoa thyrsites (Gilchrist) (Myxosporea: Multivalvulida)(1997) Shaw, Ross; Hervio, Dominique M. L. ; Devlin, Robert H.; Adamson, Martin L.The myxosporean parasite Kudoa thyrsites is reported from a new host, Aulorhynchus flavidus, the tube-snout, collected near Vancouver, British Columbia, Canada. Prevalence reached 100% and intensity 1,535 pseudocysts per 2 cm length of fish. Polymerase chain reaction primers specific for K. thyrsites amplified a fragment of the small subunit rDNA and confirmed identification. These primers also allowed detection of K. thyrsites in young (<4-mo-old) fish with no other apparent sign of infection. No inflammatory response or liquefaction of host tissue was associated with the infection. The number of pseudocysts per infected fish was not correlated with fish size or condition, although larger fish (total length) had larger pseudocysts (rs = 0.437, P < 0.001). This finding brings to 28 the number of potential hosts for the species. Kudoa thyrsites is a well recognized cause of soft flesh in netpen-reared Atlantic salmon in coastal waters of British Columbia. Tube-snouts are common in and around these netpens, and thus may be a significant host reservoir for K. thyrsites.Item Survey of Salmonid pathogens in ocean-caught fishes in British Columbia, Canada(1998) Shaw, Ross W.; Kent, Michael L.; Traxler, G. S.; Kieser, D.; Richard, J.; Dawe, S. C.; Prosperi-Porta, G.; Ketcheson, J.; Evelyn, T. P. T.A survey of wild fishes captured around marine net‐pen salmon farms and from open waters for certain salmonid pathogens was conducted in the coastal waters of British Columbia. Viral hemorrhagic septicemia virus was detected in Pacific herring Clupea pallasi, shiner perch Cymatogaster aggregata, and threespine sticklebacks Gasterosteus aculeatus. Infectious hematopoietic necrosis (IHN) virus was detected in one Pacific herring (collected well away from the farms) and in tube‐snouts Aulorhynchus flavidus and shiner perch collected from a farm experiencing an IHN outbreak. Renibacterium salmoninarum was observed in moribund Pacific hakes Merluccius productus collected from within a net‐pen and was also detected in several ocean‐caught salmon. Aeromonas salmonicida subsp. salmonicida (typical strain) was isolated from a juvenile chinook salmon Oncorhynchus tshawytscha, whereas the atypical strain of this organism was isolated from a lingcod Ophiodon elongatus. Loma salmonae (Microsporea) was observed in chinook salmon, chum salmon Oncorhynchus keta, coho salmon O. kisutch, sockeye salmon O. nerka, and pink salmon O. gorbuscha, all of which were captured well away from net‐pens. Loma spp. (Microsporea) were observed in the gills of shiner perch, lingcod, Pacific tomcod Microgadus proximus, Pacific cod Gadus macrocephalus, walleye pollock Theragra chalcogramma, and sablefish Anoplopoma fimbria; all but the first species represent new hosts for Loma. Epitheliocystis, caused by a chlamydia‐like organism, was detected in the gills of chinook salmon, chum salmon, coho salmon, pink salmon, lingcod, Pacific cod, Pacific hakes, Pacific tomcod, walleye pollock, sablefish, shiner perch, Dover soles Microstomus pacificus, Pacific sanddabs Citharichthys sordidus, and various species of rockfish Sebastes spp., most of which represent new host records for this infection.Item Modes of transmission of Loma salmonae (Microsporidia)(1998) Shaw, Ross W.; Kent, Michael L.; Adamson, M. L.Loma salmonae (Putz, Hoffman and Dunbar, 1965) Morrison and Sprague, 1981 (Microsporidia) causes prominent gill disease in pen-reared chinook salmon Oncorhynchus tshawytscha in the Pacific Northwest. Transmission of the parasite was examined by exposing Pacific salmon Oncorhynchus spp. to infectious spores by various routes: per os, intraperitoneal, intramuscular, and intravascular injection, by cohabitation with infected fish, and by placement of spores directly on the gill. All exposure methods led to infections except placement of spores on the gill. Putative sporoplasms were visible in epithelial cells of the alimentary canal within 24 h of per os exposure. L. salmonae may initially infect alimentary epithelial cells and then migrate into the lamina propia to access the blood stream. Positive results obtained by intravascular injection suggest that autoinfection from spores of ruptured xenomas in the endothelium may also occur. The cohabitation experiment demonstrates that fish may become infected by spores released from live fish.Item Genomic organization of the rat alpha(2u)-globulin gene cluster(1999) McFadyen, David A.; Addison, William; Locke, JohnThe α2u-globulins are a group of similar proteins, belonging to the lipocalin superfamily of proteins, that are synthesized in a subset of secretory tissues in rats. The many α2u-globulin isoforms are encoded by a multigene family that exhibits extensive homology. Despite a high degree of sequence identity, individual family members show diverse expression patterns involving complex hormonal, tissue-specific, and developmental regulation. Analysis suggests that there are approximately 20 α2u-globulin genes in the rat genome. We have used fluorescence in situ hybridization (FISH) to show that the α2u-globulin genes are clustered at a single site on rat Chromosome (Chr) 5 (5q22-24). Southern blots of rat genomic DNA separated by pulsed field gel electrophoresis indicated that the α2u-globulin genes are contained on two NruI fragments with a total size of 880 kbp. Analysis of three P1 clones containing α2u-globulin genes indicated that the α2u-globulin genes are tandemly arranged in a head-to-tail fashion. The organization of the α2u-globulin genes in the rat as a tandem array of single genes differs from the homologous major urinary protein genes in the mouse, which are organized as tandem arrays of divergently oriented gene pairs. The structure of these gene clusters may have consequences for the proposed function, as a pheromone transporter, for the protein products encoded by these genes.Item Iodophor treatment is not completely efficacious in preventing Loma salmonae (Microsporidia) transmission in experimentally challenged Chinook salmon, Oncorhynchus tshawytscha (Walbaum)(1999) Shaw, Ross W.; Kent, Michael L.; Adamson, M. L.Loma salmonae is a microsporidian parasite pre-dominately infecting the endothelial cells of Pacificsalmon, Oncorhynchus spp. Loma salmonae formshypertrophied cells (xenomas) which are oftenvisible as white cysts in the gills. The parasite hasbeen associated with significant mortalities inspawning wild stocks (M. Higgins, personal com-munication), hatcheries (Hauck 1984) and inmarine netpen farms in the Pacific North-west(Kent, Elliott, Groff & Hedrick 1989; Speare,Brackett & Ferguson 1989; Shaw & Kent 1999).Item High-resolution FISH mapping of the rat alpha(2u)-globulin multigene family(2000) McFadyen, David A.; Locke, JohnThe rat α2u-globulins are a group of similar proteins that are encoded by a family of approximately 20 genes located a single locus of ≤880 kbp on Chromosome (Chr) 5q. Individual members of this gene family demonstrate complex tissue, hormonal, and developmental expression patterns despite a high degree of sequence similarity among the members and consequently provide an interesting system for studying the evolution of differential gene expression. Hybridization analysis indicated that gene classes, similar to those identified at the homologous MUP locus in the mouse, do not exist within the rat α2u-globulin locus. Furthermore, cross-hybridization analysis revealed the presence of conserved sequences in the 5′ and 3′ regions flanking the α2u-globulin genes, some of which were present in an inverted orientation. We have used high-resolution fiber FISH to examine the structural organization of the α2u-globulin locus, and found the genes to be arranged as an array of both direct and inverted repeats. The organization of the rat α2u-globulin genes differs from the MUP genes and suggests different evolutionary events have reorganized these homologous sets of genes.Item Innate susceptibility differences in Chinook salmon Oncorhynchus tshawytscha to Loma salmonae (Microsporidia)(2000) Shaw, Ross W.; Kent, Michael L.; Adamson, M. L.Loma salmonae (Putz, Hoffman and Dunbar, 1965) Morrison & Sprague, 1981 (Microsporidia) is an important gill pathogen of Pacific salmon Oncorhynchus spp. in the Pacific Northwest. Three strains of chinook salmon O. tshawytscha were infected in 2 trials with L. salmonae by feeding of macerated infected gill tissue or per os as a gill tissue slurry. Intensity of infection was significantly higher in the Northern stream (NS) strain as compared to the Southern coastal (SC) and a hybrid (H) strain derived from these 2 strains. Both wet mount and histological enumeration of intensity of infection demonstrated strain differences. Survival in the NS strain was significantly lower than the other strains. The NS strain may represent a naive strain and be less able to mount an effective immune response against the parasite.Item Viability of Loma salmonae (Microsporidia) under laboratory conditions(2000) Shaw, Ross W.; Kent, Michael L.; Adamson, Martin L.The viability of the fish-infecting microsporidian Loma salmonae Morrison and Sprague, 1981 was determined under laboratory conditions by polar filament extrusion and infectivity to chinook salmon (Oncorhynchus tshawytscha). Extrusion rates of isolated spores decreased from 51.0% to 0.0% by 100 days after storage in fresh or sea water at 4 °C. Spores stored up to 95 days in either solution infected 80.0–100.0% of exposed chinook, although no spores infected fish at 100 days in one trial. Viability in Earl's balanced salt solution was tested up to 50 days, with 23.7% of spores extruding filaments and 80.0% of exposed chinook becoming infected. Spores frozen to −20 °C or −70 °C were unable to infect fish.Item Experimental and natural host specificity of Loma salmonae (Microsporidia)(2000) Shaw, Ross W.; Kent, Michael L.; Brown, A. M.; Whipps, C. M.; Adamson, M. L.The microsporidian Loma salmonae (Putz, Hoffman & Dunbar, 1965) Morrison & Sprague, 1981 has caused significant gill disease in Pacific salmon Oncorhynchus spp. Host specificity of the parasite was examined experimentally by per os challenge of selected salmonids and non-salmonids with infective chinook salmon O. tshawytscha gill material. Pink Oncorhynchus gorbuscha and chum salmon O. keta, brown Salmo trutta and brook trout Salvelinus fontinalis, and chinook salmon (controls) were positive, whereas Atlantic salmon Salmo salar and Arctic char Salvelinus alpinus were negative. In addition, no non-salmonids were susceptible to experimental exposure. Wild Pacific salmon species in British Columbia, Canada, were examined for L. salmonae during their freshwater life history stages (smolts, prespawning, spawning). All stages were infected, although infections in smolts were only detectable using a L. salmonae-specific PCR test. Many previous Loma spp. described from Oncorhychus spp. are likely L. salmonae based on host, parasite morphology, and site of infection.Item Phagocytosis of Loma salmonae (Microsporidia) spores in Atlantic salmon (Salmo salar), a resistant host, and chinook salmon (Oncorhynchus tshawytscha), a susceptible host(2001) Shaw, Ross W.; Kent, Michael L.; Adamson, M. L.The in vitro phagocytosis of Loma salmonae spores by macrophages of Atlantic salmon and two strains of chinook salmon were investigated. Opsonisation of L. salmonae with plasma factors increased uptake by head kidney macrophages. Macrophages of Atlantic salmon, which are resistant to the parasite, had a significantly higher phagocytic index (PI) than those of chinook salmon, a susceptible species. This may indicate a possible mechanism contributing to resistance in Atlantic salmon or that L. salmonae is able to evade or suppress initial binding by macrophages of chinook. Non-specific binding or lectinophagocytosis was also suggested by significantly higher PI of spores from EDTA treated plasma when compared with no plasma or heat treated plasma. In comparison, uptake of Baker's yeast Saccharomyces cerevisiae by phagocytes was not significantly different between fish species and strains for all treatments.Item Wetlands: taking the mystery out of these mysterious ecosystems(2001) Thormann, Markus; Locky, DavidIt was not long ago that many people believed wetlands to be wastelands, harbours of disease, and places worthy only of draining for other land uses. Fortunately, during the last 10-20 years, public and even political opinion has turned in favour of wetlands, with an understanding of the importance of wetlands from both social and ecological perspectives. For example, wetlands play a role in transforming the landscape (removing pollution, slowing erosion), act as a source (of water, certain kinds of sediment, plants, animals, peat, and gases), and as sinks (for flood control/water augmentation, organic matter, and carbon). Many readers will know that wetlands are unique environments and often contain the greatest comparative diversity of organisms, including plants, animals, and fungi, many of which show fidelity to only wetlands and consequently are rare.Item Quantification of vitellogenesis and its control by 20-hydroxyecdysone in the ixodid tick, Amblyomma hebraeum(2002) Friesen, Kevin; Kaufman, ReubenOvaries of the ixodid tick, Amblyomma hebraeum Koch, grew rapidly after engorgment as a result of yolk uptake. At 26 °C, oviposition began by day 10 post-engorgement, plateaued on days 16–18, and ended by day 38. Vitellin (Vt) was partially purified from ovaries of day 10 engorged ticks by gel filtration and ion exchange chromatography. This Vt comprises seven major and several minor polypeptides. Two polypeptides (211 and 148 kD) from haemolymph of engorged female ticks corresponded to minor polypeptides of similar molecular weight in the ovary. The haemolymph titre of the 211 and 148 kD polypeptides increased up to the onset of oviposition. These polypeptides were absent in males and non-vitellogenic females (day 0 engorged or day 10 partially-fed females), and were thus designated as vitellogenin (Vg). Antibodies raised against haemolymph Vg211 and 148 recognized these polypeptides in partially purified Vt, as well as six of the seven major polypeptides. Using these antibodies we developed an indirect, competitive ELISA to quantify Vg. Rise in haemolymph Vg-concentration lagged slightly behind the rise in haemolymph ecdysteroid (ES)-concentration, and Vg-synthesis was stimulated by injections of 20E into non-vitellogenic females. These observations indicate that an ES is the vitellogenic hormone in A. hebraeum.Item The mountain wolves of southwestern Manitoba(2002) Locky, DavidI first became interested in the wolves of southwestern Manitoba while conducting peatland research at Duck Mountain during the last two summers. At first all I saw were wolf tracks and scat along the logging roads, but then I began to find the remains of ungulates, usually moose that had been taken by wolves in the forested peatlands. On lucky days, the silence of hot summer afternoons was broken by the howls of wolf pups and once two adults called very close to the camp. These experiences fueled a long-time fascination with wolves and I embarked on a quest to discover more about the wolves in the region. My search led me over Duck Mountain and south to Riding Mountain National Park and the results have revealed a remarkable story of the mountain wolves of southwestern Manitoba.Item Effects of the avermectin, MK-243, on ovary development and salivary gland degeneration in the ixodid tick, Amblyomma hebraeum(2003) Friesen, Kevin; Suri, Reena; Kaufman, ReubenInjection of the avermectin analogue, MK-243, into engorged female Amblyomma hebraeum Koch resulted in reduced ovary weight, oocyte length, and ovary vitellin content. There was no significant reduction in hemolymph vitellogenin concentration in MK-243 treated ticks. Although MK-243 was previously shown to markedly reduce hemolymph 20E-concentration, injection of 20E, the vitellogenic hormone in this tick, did not reverse the effects of MK-243 on ovary development. These data suggest that MK-243 may exert its inhibition of egg development more at the level of vitellogenin uptake than vitellogenin synthesis. MK-243 also reversed salivary gland degeneration slightly, probably via its inhibitory effect on 20E-synthesis.Item Western continental wetland plant communities(2003) Locky, David; Thormann, MarkusWetland Series: This is the fourth installment in a series of papers introducing wetlands titled Wetlands – shedding some light into their murky waters. This installment introduces vascular and non-vascular plant communities of the dominant wetland classes in western continental Canada.Item Peatlands and creatures great and small: part I - vertebrates(2003) Locky, DavidThis article is Part I of a two-part series on peatland creatures. In this installment I’ll provide background information on the five wetland classes in Canada and the associated creatures there, and then focus on peatlands and vertebrates, from mammals to fish. Part II will focus on peatlands and invertebrates, including insects and amoebae, then outline wetlands from the perspective of conservation and animals. A table including all of the creatures discussed in both installments will be provided with Part II.