Recovery of a new herpesvirus from the ground squirrel (Citellus citellus).

A new herpesvirus recovered from the kidneys of mature ground squirrels (Citellus citellus) produced an effect in tissue culture cells resembling that of herpesviruses, including the formation of multinucleated syncytia and type A intranuclear inclusions. The isolate caused latent infection in the natural host, but it proved fatal for intracerebrally inoculated suckling mice and it produced pocks on the chorioallantoic membrane of embryonated eggs. Electron-microscopic examination of infected cells revealed intranuclear virus particles exhibiting a size and ultrastructure characteristic of herpesviruses. The isolate was ether-resistant and a DNA nucleic acid type was inferred from observations on inhibition by fluorinated pyrimidine. This ground squirrel herpesvirus was found to be antigenically distinct from Herpesvirus hominis and from ground squirrel cytomegalovirus, with no detectable cross-reactivity.     

Toxoplasmosis, distemper, and herpesvirus infection in a skunk (Mephitis mephitis).

A striped skunk (Mephitis mephitis) showing abnormal behavior had histopathologic lesions of toxoplasmosis and canine distemper in addition to intranuclear, eosinophilic inclusions in the reticuloendothelial cells of the spleen, liver and lung. The inclusions, on electron microscopic examination, were compatible with herpesvirus infection.     

Moesin Is Not a Receptor for Measles Virus Entry into Mouse Embryonic Stem Cells

The involvement of moesin in measles virus (MV) entry was investigated with moesin-positive and -negative mouse embryonic stem (ES) cells. MV infection of these cells was very ineffective and was independent of moesin expression. Furthermore, when these cells were transfected to express human CD46, a 100-fold increase in syncytium formation was observed with these cells and was independent of the expression of moesin. The only obvious difference between moesin-positive and -negative ES cells was the shape of the syncytia formed. Moesin-negative ES cells expressing or not expressing human CD46 formed separate pieces of fragmented syncytia which were torn apart during spreading, whereas ES cells expressing moesin exhibited typical syncytia. In addition, moesin was not detected on the surface of any murine cells or cell lines that we have tested by a flow cytometric assay with moesin-specific antibodies. These findings indicate that murine moesin is neither a receptor nor a CD46 coreceptor for MV entry into mouse ES cells. Moesin is involved in actin filament-plasma membrane interactions as a cross-linker, and it affects only the spreading and shape of MV-mediated syncytia.     

Poxvirus infection in a colony of common marmosets (Callithrix jacchus)

An epizootic poxvirus infection occurred in a colony of 80 common marmosets (Callithrix jacchus) recently introduced to a laboratory facility. Over an 18-week period, 29 of the monkeys exhibited skin lesions that persisted for 4-6 weeks. Although eight marmosets died during the outbreak, their deaths were not attributed directly to the poxvirus infection. The skin lesions developed over the entire body surface including the soles and palms. Initially characterized as erythematous papules, they quickly changed to elevated coalescing lesions with extensive scab formation. Histopathologically, the lesions revealed moderate to marked acanthosis, and they progressed to full-thickness epidermal necrosis and ulceration. Intracytoplasmic inclusion bodies were observed occasionally within degenerate keratinocytes. These inclusions most probably constituted the intracytoplasmic aggregates of viral particles observed ultrastructurally and confirmed as members of the poxvirus group by negative staining of direct skin scrapings.     

Effects of hypoxia on the behavior and physiology of kelp forest fishes

Forecasts from climate models and oceanographic observations indicate increasing deoxygenation in the global oceans and an elevated frequency and intensity of hypoxic events in the coastal zone, which have the potential to affect marine biodiversity and fisheries. Exposure to low dissolved oxygen (DO) conditions may have deleterious effects on early life stages in fishes. This study aims to identify thresholds to hypoxia while testing behavioral and physiological responses of two congeneric species of kelp forest fish to four DO levels, ranging from normoxic to hypoxic (8.7, 6.0, 4.1, and 2.2 mg O₂/L). Behavioral tests identified changes in exploratory behavior and turning bias (lateralization), whereas physiological tests focused on determining changes in hypoxia tolerance (pCrit), ventilation rates, and metabolic rates, with impacts on the resulting capacity for aerobic activity. Our findings indicated that copper rockfish (Sebastes caurinus) and blue rockfish (Sebastes mystinus) express sensitivity to hypoxia; however, the strength of the response differed between species. Copper rockfish exhibited reduced absolute lateralization and increased escape time at the lowest DO levels, whereas behavioral metrics for blue rockfish did not vary with oxygen level. Both species exhibited decreases in aerobic scope (as a function of reduced maximum metabolic rate) and increases in ventilation rates to compensate for decreasing oxygen levels. Blue rockfish had a lower pCrit and stronger acclimation response compared to copper rockfish. The differences expressed by each species suggest that acclimatization to changing ocean conditions may vary, even among related species that recruit to the same kelp forest habitat, leading to winners and losers under future ocean conditions. Exposure to hypoxia can decrease individual physiological fitness through metabolic and aerobic depression and changes to anti‐predator behavior, with implications for the outcome of ecological interactions and the management of fish stocks in the face of climate change.     

Temporal variation and feeding ecology of juvenile Sebastes in rocky intertidal tidepools of northern California, with emphasis on Sebastes melanops Girard

This study examined the seasonal use of rocky intertidal areas by young-of-the-year (YOY) Sebastes spp. at three locations in northern California, 2003 to 2005. Six species of Sebastes were noted during the study with black rockfish Sebastes melanops comprising >99% of the total number sampled. Sebastes melanops were noted in rocky intertidal areas from May to August with peak abundances occurring in May or June. Variation in recruitment and feeding was evident among years. Diet analysis, using the index of relative importance (% I _RI) and the modified index (% I _M), showed that YOY S. melanops and Sebastes mystinus consumed a variety of prey items with harpacticoid copepods and gammaridean amphipods being the dominant prey categories. The rocky intertidal appears to serve as an important habitat for YOY S. melanops in northern California.     

Comparative allometric growth of the gastrointestinal tract of two sympatric congeners, copper rockfish (Sebastes caurinus) and quillback rockfish (S. maliger)

Allometric growth of the stomach, intestine, and caeca was compared between two sympatric congeners, the copper rockfish ( Sebastes caurinus ) and the quillback rockfish ( S. maliger ), to examine the species-specific differences in their gut tract in relation to their general feeding habits. The intestine of copper rockfish was shorter and its mass less than the intestine of quillback rockfish. Copper rockfish also had a greater stomach mass and, on average, a greater number of pyloric caeca than quillback rockfish. The differences in the gut allometry between the species were consistent with differences in their general food habits as copper rockfish consume proportionally more fish and larger crustaceans than quillback rockfish.     

Application of Acoustic Telemetry to Assess Residency and Movements of Rockfish and Lingcod at Created and Natural Habitats in Prince William Sound

Loss and/or degradation of nearshore habitats have led to increased efforts to restore or enhance many of these habitats, particularly those that are deemed essential for marine fishes. Copper rockfish (Sebastes caurinus) and lingcod (Ophiodon enlongatus) are dominant members of the typical reef fish community that inhabit rocky and high-relief substrates along the Pacific Northwest. We used acoustic telemetry to document their residency and movements in the nearshore waters of Prince William Sound, Alaska in order to assess use of created reef habitat in an individual-based manner. A total of 57 fish were surgically implanted with acoustic transmitters. Forty-five fish were captured and monitored in three habitats: artificial reef, low-relief natural reef, and patchy high-relief natural reef. Within each habitat, both rockfish and lingcod exhibited long periods of residency with limited movements. Twelve rockfish were captured at the natural reefs and displaced a distance of 4.0 km to the artificial reef. Five of the 12 rockfish returned within 10 d of their release to their initial capture site. Another five of the 12 displaced fish established residency at the artificial reef through the duration of our study. Our results suggest the potential for artificial reefs to provide rockfish habitat in the event of disturbances to natural habitat.     

Systemic arteriopathy in SIV-infected rhesus macaques (Macaca mulatta)

BACKGROUND: Severe disseminated vasculopathy was observed in two simian immunodeficiency virus (SIV)-infected rhesus macaques (Macaca mulatta). These animals developed clinical signs of AIDS, including lymphadenopathy, weight loss, diarrhea and collapse. RESULTS AND DISCUSSION: Grossly, both animals showed emaciation, lymphadenopathy, vegetations on the mitral valve, renal infarcts and a dilated intestine; one animal had multifocal hemorrhages in multiple organs. Histologically, both cases had disseminated arteriopathy characterized by intimal thickening and fibrosis with varying degrees of vasculitis. The lesion was prominent in the kidney, intestine, pancreas, liver, heart, lymph nodes, spleen and testis. Occasional venules had intimal thickening. Both cases had cytomegalovirus (CMV) infection with intranuclear inclusions, CMV antigen and nucleic acid; some inclusions were observed in endothelial cells within some of the vascular lesions in one of the two. These data suggest that CMV caused the unusual lesions.     

Habitat characteristics of juvenile cowcod, <Emphasis Type="Italic">Sebastes levis</Emphasis> (Scorpaenidae), in Southern California

We characterized habitat requirements of juvenile cowcod, Sebastes levis, using information from surveys conducted aboard the manned research submersible Delta. We conducted 303 dive surveys on rocky banks and outcrops in water depths between 28 and 365 m in southern and central California, covering 483 km (963,940 m²) of seafloor. We counted 549,263 fishes from at least 134 species; 216 individuals were juvenile cowcod, S. levis, of 45 cm or less in total length (TL). Juvenile cowcod occupied depths between 52 and 330 m and demonstrated ontogenetic shifts in their habitat associations. Small fish (5–20 cm TL) lived primarily among cobbles or cobbles and small boulders. As fish grew, they moved into high-relief rock habitats, including boulder fields and rock ridges. Small cowcods were found with pygmy, Sebastes wilsoni, and swordspine, Sebastes ensifer, rockfishes. Larger juveniles often associated with juvenile bocaccio, Sebastes paucispinis, juvenile widow rockfish, Sebastes entomelas, and squarespot rockfish, Sebastes hopkinsi. Our study resulted in a characterization of seafloor habitats on a small spatial scale that is relevant to juvenile cowcod nursery areas, which is important when considering effective management strategies for this overfished species.     

Behavioral ecology of young-of-the-year kelp rockfish, Sebastes atrovirens Jordan and Gilbert (Pisces: Scorpaenidae)

Young-of-the-year (YOY) kelp rockfish, Sebastes atrovirens, recruit initially to the canopy of the giant kelp, Macrocystis pyrifera (L.), along the coast of central California. During the summer of 1991, I observed major fluctuations in YOY kelp rockfish abundance in the canopy before the onset of a vertical migration downward to the Macrocystis holdfasts. Within the Macrocystis canopy, YOY kelp rockfish make a series of microhabitat shifts preparatory to their downward migration, forming smaller and more closely held aggregations. Experimental manipulations of Macrocystis architecture indicate that YOY kelp rockfish densities are reduced in areas with only small Macrocystis (few stipes) compared to unmanipulated areas with a range of Macrocystis sizes. Unusually large Macrocystis, created by binding multiple kelps together, did not compensate for a preponderance of small Macrocystis in the surrounding areas. In unmanipulated habitat, YOY kelp rockfish densities were correlated with the size of the Macrocystis (number of stipes). Habitat selection in the canopy and holdfasts appears to be behavioral and is closely tied to the architecture of the alga. The onset of the downward migration appears to be triggered by a combination of ontogenetic and environmental cues.     

Identification of biomarkers indicative of barotrauma and recovery in black rockfish Sebastes melanops

A Sebastes-specific complementary DNA (cDNA) microarray was developed to identify potential biomarkers involved in the capture stress and recovery of Sebastes species if they are assisted in returning to their original depth of capture following barotrauma. Black rockfish Sebastes melanops were exposed to simulated decompression from 450 kPa (c. 35 m depth) (which resulted in barotrauma) and subsequent recompression. Sebastes melanops were sampled for liver tissue at days 3, 15 and 31 post-barotrauma. Potential candidate genes were identified from the microarray and then quantitative real-time PCR (qrt-PCR) was used to validate expression levels in biological replicates. Six potential biomarkers associated with the innate immune system were identified that were up-regulated in liver tissue at 3 days post-barotrauma: complement C1q-like protein 2, complement component C3, complement regulatory plasma protein, serum amyloid A-5, c-type lysozyme and hepcidin precursor type I. In addition, complement c1q was correlated to the presence of a ruptured swimbladder, providing further support that this gene may be a good biomarker of injury and recovery. Immune genes were no longer up-regulated at day 31 post-barotrauma, a good indication of recovery in S. melanops.     

Examination of Virus-Infected Cultured Cells by Scanning Electron Microscopy

The scanning electron microscope (SEM) was used to detect changes in morphology of BSC-1 cells after infection with vesicular stomatitis virus (VSV) or herpes simplex virus. The morphological changes of the infected cells were related to the length of time of infection and to the virus used. Extensive alteration to the cytoplasm could be seen 24 and 48 hr after infection with 10 and 320 TCID(50) of VSV. Within 24 hr after infection with 1 TCID(50) of herpes simplex, a few nuclei were swollen. However, 72 hr after infection with 100 TCID(50) of herpesvirus, many nuclei were swollen and appeared in large aggregates, probably representing formation of a polykaryocyte. Corresponding samples stained with May-Grunwald-Giemsa were observed in the light microscope and morphological changes were compared to those seen with the SEM.     

Treatment of Microcotyle sebastis infestation in cultured rockfish Sebastes schlegeli by oral administration of praziquantel in combination with cimetidine

The effect of cimetidine on the treatment efficacy of praziquantel against Microcotyle sebastis infestation in cultured rockfish Sebastes schlegeli was investigated. Juvenile rockfish were divided into 7 groups, and orally administered praziquantel alone (50, 100 and 200 mg kg(-1) body wt, BW) or in combination with cimetidine at a dose of 200 mg kg(-1) BW for each praziquantel dose. The fish in the control group were administered only saline. The results clearly showed that coadministration of cimetidine with praziquantel led to a significantly increased treatment efficacy of the latter drug, and consequently would lead to a lowering of the total dose of praziquantel, and a reduction in the administration times and costs for the treatment of M. sebastis infestation in cultured rockfish.     

Isolation and Characterization of Twelve Microsatellite Loci for Rockfish (Sebastes)

We describe the first microsatellites for rockfishes in the diverse genus Sebastes. Clones containing microsatellites were isolated from the genomic library of a quillback rockfish, Sebastes maliger. Twelve microsatellites are characterized; six of these are polymorphic in quillback rockfish, and eight are polymorphic in at least one rockfish species on which they were tested. The number of alleles per variable locus ranged from 4 to 15 and averaged 6.8. The expected heterozygosities ranged from 0.38 to 0.79 and averaged 0.60 in these loci. These loci should prove valuable in studies examining species identification, population genetics, hybridization, paternity, kinship, and microsatellite evolution. Received September 8, 1998; accepted November 23, 1998.     

Purification and characterization of luteinizing hormone from pituitary glands of rockfish, Sebastes schlegeli

To acquire greater knowledge of the reproductive function of luteinizing hormone (LH) in the viviparous rockfish Sebastes schlegeli, LH from the pituitary glands of mature rockfish was isolated, purified, and localized and its biological activity was characterized. The molecular mass of purified LH was estimated to be approximately 33 kDa, similar to that of known LH. When rockfish LH was purified by reverse-phase high-performance liquid chromatography, its N-terminal amino acid sequences were found to coincide with those of predicted cDNA sequences of rockfish gonadotropin α (ssGTHα) and ssLHβ mature peptides. Immunocytochemical analysis using antisera against ssGTHα (molecular weight [MW], ~14.5 kDa) and ssLHβ (MW, ~18.5 kDa) indicated that the LH-producing cells are mainly distributed throughout the proximal pars distalis and along the periphery of the pars intermedia. Further, in vitro ovarian follicle analysis demonstrated that purified intact rockfish LH significantly enhances E(2) secretion in a dose-dependent manner. This is the first report on the purification and characterization of LH from a viviparous teleost, and these results will enable future research and increase our understanding of the mechanisms underlying the maturation of such fish.     

Expression analysis of lipopolysaccharide-and/or concanavalin A/phorbol myristate acetate-stimulated black rockfish peripheral blood leukocytes using a cDNA microarray to identify up-regulated genes

The responses of peripheral blood leucocytes (PBLs) from the black rockfish Sebastes schlegelii stimulated with lipopolysaccharides (LPS) and/or concanavalin A/phorbol myristate acetate (Con A/PMA) were investigated using a cDNA microarray consisting of 5,088 clones. This analysis showed that 254 unique genes were more than twofold upregulated, and they were selected for sequencing. Among the mitogens, 84 genes were more than twofold upregulated in LPS-stimulated PBLs, and 112 genes were induced in Con A/PMA-stimulated PBLs. Moreover, 58 other genes were more than twofold upregulated in PBLs stimulated with both LPS and Con A/PMA. Other genes were not significantly induced. Overall, these results suggest that certain genes in black rockfish have important roles in physiological and pathological processes. Furthermore, the microarray analysis suggested a promising tool for immune mechanisms in teleost fish.     

Lipid class composition of the viviparous yellowtail rockfish over a reproductive cycle

Triacylglycerols (TAG) were the dominant lipids in liver tissue of both sexes of the viviparous yellowtail rockfish Sebastes flavidus during the spring and summer when greatest feeding occurred. Significant declines in liver TAG during the winter corresponded to increased concentrations of polar lipids (PL), the main component of cell membranes. Elevated PL in female livers relative to those of males preceded the period of ovarian enlargement and may be attributed to the production of vitellogenin. During late vitellogenesis and gestation, ovaries contained significantly elevated concentrations of PL, TAG, and cholesterol. Since yellowtail rockfish are highly fecund and viviparous, large quantities of ovarian PL are required for proliferation of the cell membranes in developing larval tissues. TAG accumulated in ovaries in lower concentrations than PL and were likely metabolized as the main source of energy during gestation. This pattern of ovarian PL concentrations exceeding those of TAG and the presence of oil globules, may be unique to highly fecund, viviparous teleosts and signify an alternative profile to those previously documented for oviparous species. Testes at maximum I _G were only 7% of maximum ovarian size, composed of mainly PL, and lacked a defined lipid dynamic pattern across the reproductive cycle.     

Viral inclusions in raccoon liver cells.

Three young raccoons (Procyon lotor), two from Michigan and one from Arizona, died suddenly from acute infections. Intranuclear inclusion bodies and viral particles typical of herpesvirus were seen in liver cells from all three. Inclusions also were seen in the nuclei of endothelial cells in the lung, liver, glomeruli and reticuloendothelial cells of the spleen. The source of the infection was not determined, but possible transmission from other species could not be ruled out.