Efficacy of soluble recombinant FliC protein from Salmonella enterica serovar enteritidis as a potential vaccine candidate against homologous challenge in chickens

FliC, the flagellin antigen of Salmonella Enteritidis, was tested as a vaccine candidate for protective effect against a homologous challenge in chickens. After immunization with recombinant FliC (rFliC) or administration of phosphate-buffered saline (PBS) at 56 days old, the chickens were challenged with 10(9) colony-forming units of Salmonella Enteritidis at 76 days old. The vaccinated birds showed significantly decreased bacterial counts in the liver and cecal contents compared to those administered PBS at 7 days postchallenge, but the protection was partial. The replication experiment also showed a similar result. In both experiments, vaccination induced an increased level of serum anti-rFliC IgG, which was also reactive to the native flagella. The intestinal IgA level was slightly higher in the vaccinated birds than in the control. However, neither the proliferative response nor interferon-gamma secretion of splenic cells upon stimulation with rFliC was induced. Therefore, the effect of rFliC as a vaccine is limited, and further improvement is needed.     

Development of microsatellite markers and evaluation of genetic diversity of the Amazonian ornamental fish Pterophyllum scalare

The objective of the present work was to develop species-specific microsatellite markers for P. scalare and to analyze the diversity and genetic structure of a wild population, from the Amazon River, and three commercial stocks (common, marble, and clown morphological variants), from farmers in Vieras-Minas Gerais. Through microsatellite-enriched genetic libraries, 11 microsatellite markers with adequate amplification patterns were characterized. Population genetic analysis identified eight polymorphic loci that generated 66 alleles ranging from two alleles (PSCA1B3) to nine (PSCA2H1). The polymorphic information content ranged from 0.031 to 0.827. High genetic differentiation was observed between the wild population and the stocks, and moderate differentiation between the three stocks. Deviation in the Hardy-Weinberg equilibrium was observed in one locus in the wild population, in five loci in the common morphological variant, in two in the marble, and in two in the clown morphological variant. Bayesian analysis of genetic structure revealed the existence of two clusters, one represented by the natural population and the other by the stocks. The developed microsatellite markers serve as a tool for the analysis of diversity and genetic structure and conservation studies of P. scalare.

     

Identification and validation of QTLs for cold tolerance at the booting stage and other agronomic traits in a rice cross of a Japanese tolerant variety,Hananomai, and a NERICA parent,WAB56-104

In Africa, cold temperatures occur in the highlands of East and Southern Africa and in some areas of the Sahel region of West Africa leading to substantial rice yield losses. Cold tolerance (CT) at booting stage on basis of spikelet fertility after cold water irrigation was evaluated using F₂ population derived from a cross between temperate japonica, Hananomai, and tropical japonica, WAB56-104. Two Quantitative trait loci (QTLs) for CT were detected on chromosome 8 and 10 with enhanced effects on the trait coming from Hananomai and WAB56-104 allele, respectively. The QTLs explained 30% and 33% of phenotypic variation in spikelet fertility, respectively. CT was negatively correlated with panicle number (r = ?0.35, p < 0.01) and positively correlated with panicle weight (r = 0.61, p < 0.001). Selected BC₁F₄ and BC₁F₅ genotypes having homozygous alleles for both CT QTLs exhibited higher spikelet fertility under cold stress. The identified QTLs will be useful in the development of cold-tolerant varieties for production in high altitude areas through marker-assisted selection.     

Partial migration of juvenile temperate seabass <Emphasis Type="Italic">Lateolabrax japonicus</Emphasis>: a versatile survival strategy

Partial migration describes intrapopulation variation in the migratory behavior, i.e. some individuals from a population migrate to low-salinity river areas, while others remain in coastal areas. This paper reviews the partial migration pattern of juvenile temperate seabass Lateolabrax japonicus, which is a migration pattern not commonly seen in Japan. Seabass spawn offshore, and eggs and larvae are transported to coastal areas. Some of these juveniles then ascend rivers, while others remain in coastal areas. Juveniles efficiently use physical structures in their habitat; they use tidal currents to ascend rivers in macrotidal estuaries, while they use the salt wedge in microtidal estuaries. Once juveniles ascend the river, they can feed on the abundant prey and attain more rapid growth than those remaining in coastal areas. As estuaries are highly productive areas, they play significant roles as nurseries for juveniles of various fishes. However, compared with coastal areas, the relative area of estuaries is considerably smaller and its environmental conditions are more variable. For example, nearly 40% of adult seabass in Tango Bay were estimated to use estuarine areas as a nursery, while the other 60% use coastal areas during their juvenile stage. Using both estuaries and coastal areas through partial migration during the juvenile stage is concluded to contribute to the stabilization and yield of seabass populations.     

Identification of skeletal muscle satellite cells by transfecting EGFP driven by skeletal alpha-actin promoter

In isolating skeletal muscle satellite cells, sometimes a problem is encountered in removing contaminating nonmyogenic cells. In the present study, we constructed a novel vector, pSKA-EGFP, which achieves the expression of enhanced green fluorescent protein (EGFP) exclusively in myogenic cells under the control of skeletal alpha-actin promoter when transfected to primary cultured cells from skeletal muscle. Cells from rat skeletal muscle positive for EGFP after transfecting with pSKA-EGFP were all positive for desmin and none of the nonmyogenic cells expressed EGFP, indicating that the expression of EGFP is specific to myogenic cells. Among the cells positive for EGFP were proliferating cells, presumably satellite cells. In addition, EGFP positive cells derived from horse skeletal muscle after transfecting pSKA-EGFP in vitro formed multinuclear myotubes, indicating that myogenic expression of EGFP driven by skeletal alpha-actin was achieved also in the equine cells. These results indicated that pSKA-EGFP vector will be useful in identifying and following up the satellite cells in real time, and also permit us to isolate satellite cells in combination with fluorescence-activated cell sorting (FACS).     

Cytopathogenicity of classical swine fever viruses that do not show the exaltation of Newcastle disease virus is associated with accumulation of NS3 in serum-free cultured cell lines

Pestiviruses can be distinguished as two biotypes, cytopathogenic (cp) and noncytopathogenic (noncp), by the morphological changes that they induce during growth in cultured cells. In this study, the cp phenotype of several classical swine fever viruses (CSFV) was evaluated by the detections of the nonstructural proteins NS2-3 and NS3 using immunoprecipitation and Western blotting in different porcine cell lines. Most CSFVs that showed the exaltation of Newcastle disease virus (END) phenomenon (END(+) viruses) did not induce cytopathic effect (CPE) in any cell line, and detections of NS2-3 and NS3 showed a strong signal for NS2-3 in the END(+) virus-infected cells. However, clear CPE was observed in serum-free cultured cells (FS-L3 and CPK-NS) infected with viruses that induce intrinsic interference but did not show the END phenomenon (END(-) viruses), and signal of NS3 was strongly detected than that of NS2-3 in these cells at 72 hr after infection. As the results of the analysis of FS-L3 cells infected with ALD (END(+) virus) and ALD-END(-) virus (END(-) virus) at several incubations, the signal of NS3 detected was strengthened with CPE that become evident progressively. These results suggest that CPE is associated with the accumulation of NS3, which is promoted in serum-free cell lines infected with END(-) viruses. Thus, indicating there is a close relationship between CPE and the quantity of NS3 produced in END(-) CSFV infection.     

Quantitative changes in serum concentration of bovine gut chitinase in Theileria infection

Bovine gut chitinase is exclusively produced in the liver and secreted into the blood. In the present study, we established a semi-quantitative method by Western blot analysis for measurement of the chitinase content in blood and examined its alteration during postnatal development and experimental infection with hemoprotozoan parasite in cattle. Its serum levels from 1 week to 1 year of age showed a significant increase only in 3-4-month-old group. The plasma concentration of the gut chitinase was not changed during acute inflammation caused by lipopolysaccharide but increased gradually after a Theileria injection and peaked at 52 days post-infection. It appears that the increase in the blood chitinase levels might be a defensive response in cattle against protozoan infection.     

Thiazole orange positive platelets in a dog with Evans' syndrome

We examined transition for the percentage of reticulated platelets (RP%) and platelet count in a canine case of Evans' syndrome. The result demonstrated that measurement of the RP% can be useful in evaluating platelet production in the bone marrow and response to treatment.     

Effects of the neutrophil elastase inhibitor (ONO-6818) on acetic acid induced colitis in Syrian hamsters

Neutrophil elastase (NE) released from neutrophils during inflammation is related to tissue disturbance and organ failure. We investigated the effects of an orally active NE inhibitor, ONO-6818, on acetic acid induced colitis in Syrian hamsters. The ulcer area, hemoglobin level in the colonic lumen, NE activity, and tissue myeloperoxidase (MPO) activity in the colitis control animals were significantly increased compared to the normal control ones. Either oral or subcutaneous treatment with ONO-6818 had significant inhibitory effects on the ulcer area, hemoglobin level and NE activity in the colonic lumen, but ONO-6818 did not have a significant inhibitory effect on tissue MPO activity. We conclude that NE is closely related to the development of inflammation in acetic acid-induced colitis in Syrian hamsters and that the condition is improved by the inhibition of NE.