Steroidal regulation of the aromatase gene and dominant behavior in the false clown anemonefish Amphiprion ocellaris

Fisheries Science - The interaction between cortisol and aromatase may be a critical factor in sex determination or sex changes in teleost species. High cortisol concentrations inhibit...     

Purification and characterization of carbon monoxide dehydrogenase from the aerobic hyperthermophilic archaeon <Emphasis Type="Italic">Aeropyrum pernix</Emphasis>

The aerobic hyperthermophilic archaeon Aeropyrum pernix expresses carbon monoxide (CO) oxidation activity under heterotrophic growth conditions. Using activity stain gel analysis, CO oxidation activity was detected in a protein with a molecular mass of 210 kDa. The 210 kDa CODH protein was purified to homogeneity from A. pernix. Aeropyrum Mo-CODH catalyzed the oxidation of CO with a specific activity of 2.1 μmol CO min⁻¹ mg⁻¹ at 95°C, pH 8.0 using methyl viologen as the electron acceptor. The CODH protein showed high oxygen and thermo stability. The protein contains three subunits: L (86.6 kDa), M (34.5 kDa), and S (12.6 kDa), which form the LM₂S complex. The molecular mass of the complex was calculated by gel filtration and found to be 163.7 kDa. N-terminal amino acid sequencing and peptide mass fingerprinting analysis of the subunits indicated that they corresponded to NP_148462.1, NP_148464.2, and NP_148465.1, and their genes annotated the molybdo iron-sulfur flavoprotein carbon monoxide dehydrogenase S, L, and M subunits, respectively. Phylogenetic analysis revealed that CODH belongs to a novel clade of diverse CODHs.     

Efficacy of leflunomide for treatment of refractory inflammatory colorectal polyps in 15 Miniature Dachshunds

Inflammatory colorectal polyp (ICRP), common in miniature dachshunds, presents with hematochezia, tenesmus and mucoid feces. Although an 80% response rate has been reported when treated with prednisolone and cyclosporine, effective treatment is needed for the remaining 20% of ICRP dogs. Leflunomide is an immunosuppressive drug reported as effective in several immune-mediated diseases. In the present study, we retrospectively evaluated the efficacy and adverse effects of leflunomide in 15 ICRP dogs that were refractory to treatment with prednisolone and cyclosporine. Treatment efficacy was assessed by endoscopy, clinical symptoms and rectal palpation. Adverse effects were determined by clinical symptoms and blood testing during follow-up. The leflunomide treatment response rate was 93.3%. The median dosage of leflunomide and the median response time were 3 mg/kg (range: 1.7–4.0 mg/kg) and 35 days (range: 20–119 days), respectively. Adverse effects observed included lethargy (3 dogs), anorexia (1 dog), respiratory symptoms (1 dog), leukocytopenia (2 dogs), thrombocytopenia (1 dog), anemia (1 dog) and liver enzyme elevation (8 dogs). Most of the adverse effects improved with symptomatic treatment and leflunomide discontinuation or dosage reduction. In conclusion, leflunomide treatment is effective in ICRP dogs refractory to treatment with prednisolone and cyclosporine. Because several adverse effects were observed, close monitoring is needed during leflunomide treatment follow-up.     

Transient appearance of the epithelial invagination in the olfactory pit of chick embryos

In this study, immunohistochemical analysis has been performed using neuronal markers (GAP43, NCAM and PGP 9.5) to characterize the epithelial invagination in the medial wall of the olfactory pit in the chick embryos. At stages 26–27, the epithelial invagination was primarily composed of characteristic round-shaped cells, which were negative for neuronal markers. These cells were also found in the medial wall of the olfactory pit at stage 24, whereas the epithelial invagination was not observed at any stages other than stages 26–27. The possible relationship between the round-shaped cells and the migratory cells is discussed.     

Fatal suppurative meningoencephalitis caused by Klebsiella pneumoniae in two calves

One calf died (No. 1) and another was euthanized following astasia (No. 2). Histopathological examination revealed suppurative meningoencephalitis in these calves. Klebsiella pneumoniae antigens were detected in lesions. Thymocytes were decreased in the thymus cortex in both cases. 16S rRNA gene sequencing of the No. 1 isolate and bacterial extracts from formalin fixed paraffin embedded sections of No. 2 revealed that both samples were K. pneumoniae. The No. 1 isolate showed multidrug resistance against penicillin antibiotics, fosfomycin, streptomycin, macrolide antibiotics, tetracycline antibiotics, and clindamycin. Immunosuppression is a significant septicemic K. pneumoniae infection risk factor. Our study provides new aspects regarding K. pneumoniae infections in cattle, bacterial meningoencephalitis differentiation, and K. pneumoniae and bacterial meningoencephalitis treatments.     

Detection of QTLs to reduce cadmium content in rice grains using LAC23/Koshihikari chromosome segment substitution lines

To advance the identification of quantitative trait loci (QTLs) to reduce Cd content in rice (Oryza sativa L.) grains and breed low-Cd cultivars, we developed a novel population consisting of 46 chromosome segment substitution lines (CSSLs) in which donor segments of LAC23, a cultivar reported to have a low grain Cd content, were substituted into the Koshihikari genetic background. The parental cultivars and 32 CSSLs (the minimum set required for whole-genome coverage) were grown in two fields with different natural levels of soil Cd. QTL mapping by single-marker analysis using ANOVA indicated that eight chromosomal regions were associated with grain Cd content and detected a major QTL (qlGCd3) with a high F-test value in both fields (F = 9.19 and 5.60) on the long arm of chromosome 3. The LAC23 allele at qlGCd3 was associated with reduced grain Cd levels and appeared to reduce Cd transport from the shoots to the grains. Fine substitution mapping delimited qlGCd3 to a 3.5-Mbp region. Our results suggest that the low-Cd trait of LAC23 is controlled by multiple QTLs, and qlGCd3 is a promising candidate QTL to reduce the Cd level of rice grain.     

Differentiation of feline coronavirus type I and II infections by virus neutralization test

Feline coronavirus (FCoV) is divided into two types I and II, based on their growth in vitro and antigenicity. In this study, virus neutralization (VN) test was applied for type differentiation of FCoV infections. Sera of cats which were clinically and serologically diagnosed as feline infectious peritonitis (FIP) possessed significantly higher VN titers to type I FCoV, and sera from cats experimentally infected with FIPV type II had high VN titers to type II but not type I viruses. A total of 79 cat sera collected in the years between 2004 and 2005 were examined to evaluate seroprevalence by the VN test, showing the following results: (1) 50 cats (63.3%) were sero-positive to FCoV; (2) of the 50 FCoV positive cat serum samples, 49 (98%) showed significantly higher titers to type I virus and only one (2%) for type II virus. These results indicate that the VN test described here can be used for serological differentiation of FCoV infections of cats, and that FCoV type I is a dominant type in recent years of Japan.     

Do cattle (Bos taurus) retain an association of a visual cue with a food reward for a year?

Use of visual cues to locate specific food resources from a distance is a critical ability of animals foraging in a spatially heterogeneous environment. However, relatively little is known about how long animals can retain the learned cue–reward association without reinforcement. We compared feeding behavior of experienced and naive Japanese Black cows (Bos taurus) in discovering food locations in a pasture. Experienced animals had been trained to respond to a visual cue (plastic washtub) for a preferred food (grain‐based concentrate) 1 year prior to the experiment, while naive animals had no exposure to the cue. Cows were tested individually in a test arena including tubs filled with the concentrate on three successive days (Days 1–3). Experienced cows located the first tub more quickly and visited more tubs than naive cows on Day 1 (usually P < 0.05), but these differences disappeared on Days 2 and 3. The performance of experienced cows tended to increase from Day 1 to Day 2 and level off thereafter. Our results suggest that Japanese Black cows can associate a visual cue with a food reward within a day and retain the association for 1 year despite a slight decay.     

Trophodynamic structure of a swampy bog at the climax stage of limnological succession II. Bacterioplankton dynamics

Matsumi-ike Bog is a swampy bog that has attained the climax stage of limnological succession. The dynamics of bacterioplankton were studied in relation to the influence of environment factors. The water temperature was shown primarily affect bacterial dynamics as a limiting factor throughout the year. The second most profound factor on the dynamics was the concentration of dissolved organic carbon (DOC) when dead phytoplankton were the major DOC source in the bog, whereas phosphate concentration was most important in the periods when the dead emergent plants were responsible for the DOC supply.