Dystrophin-deficient muscular dystrophy in a Toy Poodle with a single base pair insertion in exon 45 of the Duchenne muscular dystrophy gene

A 10-month-old, intact male Toy Poodle was referred for a postural abnormality. Blood biochemical tests revealed a marked increase in plasma creatine phosphokinase (CPK) concentration. The isoenzyme test showed that 99% of serum CPK consisted of CPK-MM. Histopathological evaluation of muscle biopsy samples confirmed scattered degeneration and necrosis of myofibers. Immunohistochemistry for dystrophin showed an absence of staining in muscle cells. Based on these findings, the dog was diagnosed with dystrophin-deficient muscular dystrophy. Whole genome sequencing using genomic DNA extracted from blood revealed a single base pair insertion in exon 45 of the Duchenne muscular dystrophy (DMD) gene. This is the first report on muscular dystrophy in Toy Poodles and identified a novel mutation in the DMD gene.     

Nitrogen and oxygen isotope enrichment factors of nitrate at different denitrification rates in an agricultural soil

ABSTRACT

Quantitative evaluation of denitrification by the dual isotope approach, which measures the stable isotope ratios of nitrogen (δ¹⁵N) and oxygen (δ¹⁸O) in nitrate, has been hampered by the wide range of values reported for the ratio of enrichment factors for ¹⁵N and ¹⁸O (¹⁵ε and ¹⁸ε, respectively) during denitrification. The objectives of this study were to determine ¹⁵ε and ¹⁸ε values at different denitrification rates under controlled conditions, and to infer possible mechanisms by which the ¹⁸ε/¹⁵ε ratio is influenced under different conditions. Column experiments were conducted at 25, 15, and 10°C, which enabled determination of ¹⁵ε and ¹⁸ε at different denitrification rates, in the absence of nitrate replenishment from ammonium oxidation and other sources. The values of ¹⁵ε and ¹⁸ε ranged from ?11.8 to ?14.9‰ and from ?8.4 to ?15.9‰, respectively, with ¹⁵ε less sensitive to changes in the denitrification rates. The resultant ¹⁸ε/¹⁵ε ratio, ranging from 0.70 to 1.17, was close to the values reported for sediment incubations, and larger than those for groundwater systems. These results are consistent with the explanations that ¹⁸ε/¹⁵ε value itself is close to unity during denitrification, and that at smaller denitrification rates, concurrent reactions including re-oxidation of nitrite to nitrate lead to smaller apparent fractionation of ¹⁸O and smaller ¹⁸ε/¹⁵ε ratios. This suggests that while linear relationships between δ¹⁸O and δ¹⁵N give a strong evidence of denitrification, apparent ¹⁸ε/¹⁵ε values are site specific and depend on the ambient conditions. In evaluating denitrification in such systems, we suggest the use of ¹⁵ε in preference to ¹⁸ε because ¹⁵ε is less sensitive to denitrification rates.     

Contribution of enhanced efflux to reduced susceptibility of Salmonella enterica serovar Choleraesuis to fluoroquinolone and other antimicrobials

We examined antimicrobial susceptibility and efflux systems in laboratory-derived mutants of Salmonella enterica serovar Choleraesuis selected by culture on fluoroquinolone-containing plates. The mutants exhibited decreased susceptibilities to quinolones and several other antimicrobials. Mutations in the gyrA gene were not always found in the mutants. Accumulation assays revealed that intracellular enrofloxacin concentrations were significantly lower in the mutants compared with parent isolates. Increased expression of acrB mRNA can explain the decreased susceptibilities to several antimicrobials but not in the case of carbonyl cyanide m-chlorophenylhydrazone (CCCP). Decreased susceptibility to CCCP may result from the increased expression of emrA mRNA. These results suggest that the enhancement of multiple efflux pumps is responsible for decreased susceptibilities to several antimicrobials in the laboratory-derived mutants.     

Local positive feedback regulation determines cell shape in root hair cells

The specification and maintenance of growth sites are tightly regulated during cell morphogenesis in all organisms. ROOT HAIR DEFECTIVE 2 reduced nicotinamide adenine dinucleotide phosphate (RHD2 NADPH) oxidase-derived reactive oxygen species (ROS) stimulate a Ca2+ influx into the cytoplasm that is required for root hair growth in Arabidopsis thaliana. We found that Ca2+, in turn, activated the RHD2 NADPH oxidase to produce ROS at the growing point in the root hair. Together, these components could establish a means of positive feedback regulation that maintains an active growth site in expanding root hair cells. Because the location and stability of growth sites predict the ultimate form of a plant cell, our findings demonstrate how a positive feedback mechanism involving RHD2, ROS, and Ca2+ can determine cell shape.     

Molecular characterization of South and East Asian melon, Cucumis melo L., and the origin of Group Conomon var. makuwa and var. conomon revealed by RAPD analysis

The genetic diversity and relationship among South and East Asian melon Cucumis melo L. were studied by using RAPD analysis of 69 accessions of melon from India, Myanmar, China, Korea, and Japan. The genetic diversity was large in India, and quite small in Group Conomon var. makuwa and var. conomon from East Asia, clearly indicating a decrease in genetic variation from India toward the east. Cluster analysis based on genetic distance classified 17 groups of accessions into two major clusters: cluster I comprising 12 groups of accessions from India and Myanmar and cluster II that included five groups of accessions of Group Conomon var. makuwa and var. conomon from East Asia. Cluster I was further divided into three subclusters, of which subclusters Ib and Ic included small- and large-seed type populations, respectively. Therefore, this division was based on their seed size, not cultivation area. The large-seed type from east India was differently included in the subcluster of small-seed type (Ib). A total of 122 plants of 69 accessions were classified into three major clusters and subclusters: clusters I and II comprised melon accessions mostly from India and Myanmar, and cluster III comprised Group Conomon var. makuwa and var. conomon from East Asia. The frequency of large- and small-seed types was different between clusters I and II, also indicating genetic differentiation between large- and small-seed types. One plant of the small-seed type from east India was differently included in cluster III, and two plants from east India were classified into subcluster IV. These results clearly showed that South Asian melon is genetically differentiated by their seed size, and that small-seed type melon in east India is closely related to Group Conomon var. makuwa and var. conomon.     

Improvement of a rapid diagnosis kit to detect either influenza A or B virus infections

To improve the sensitivity of a kit, ESPLINE INFLUENZA A&B for rapid diagnosis of influenza by detecting influenza A or B virus specific nucleoproteins (NP), the ESPLINE INFLUENZA A&B-N was developed by using newly established monoclonal antibodies (MAbs) to the respective NP molecule. MAbs FVA2-11 and FrB1-03 recognize the epitope on the amino acid region 59-130aa of the NP molecule of influenza A virus, and that on the region 72-191aa of the NP of influenza B virus, respectively. The new kit detected influenza A and B virus antigens with a detection limit of 10(2.0)-10 (2.7) pfu/test, which is 4-1000 times higher than that of the original kit. Importantly, this kit detected each of influenza A viruses of the known hemagglutinin (HA) subtypes (H1-H15) including the H5N1 viruses recently isolated from human and avian sources in Asia. The kit also detected all of the 15 representative influenza B virus strains tested. The ESPLINE INFLUENZA A&B-N is thus a rapid and highly sensitive and specific kit for the diagnosis of either influenza A or B virus infections.     

Molecular analysis of genetic diversity in melon landraces (<Emphasis Type="Italic">Cucumis</Emphasis><Emphasis Type="Italic">melo</Emphasis> L.) from Myanmar and their relationship with melon germplasm from East and South Asia

Genetic diversity of Myanmar melon was evaluated by analysis of 27 RAPD markers and morphological characters using 41 accessions of melon landraces of which 36 accessions were small-seed type. The gene diversity was 0.239, higher than for group Conomon from East Asia and equivalent to Indian melon populations. Melon accessions were classified into six major clusters. The largest cluster IV comprised mainly group Conomon which was closely related to cluster V consisting of mainly group Agrestis. Most of the accessions of group Cantalupensis were grouped into clusters II or VII and were distantly related to groups Conomon and Agrestis. The genetic relationship to melon accessions from neighboring countries was analyzed. The 24 accessions of clusters IV and V were mostly clustered together with small-seed type melon of India, but the 14 accessions of clusters VI and VII were mostly clustered together with large-seed type melon of India. These results indicated that the genetic diversity of Indian melon is conserved in Myanmar. Genetic introgression among melon groups through spontaneous hybridization was also indicated and was considered important to maintain or increase the genetic diversity in Myanmar.     

Antigen-binding and protein G-binding abilities of immunoglobulin G in hyperimmunized cow's milk treated under various conditions

Skim milk and whey prepared from milk secreted by cows that had been injected with bacteria were kept under various conditions, and the antigen‐binding and protein G‐binding abilities of immunoglobulin G (IgG) in the milk samples were investigated. More than 85% of the original antigen‐binding and protein G‐binding abilities remained when the skim milk was heated at 63°C for 60 min or kept at a pH range of 4–10 for 24 h at 37°C. Both of the high abilities were maintained on pepsin treatment above pH 4 and intestinal proteinase treatments. Little antigen‐binding and protein G‐binding abilities decreased upon storage of the powdered skim milk for 12 months at room temperature. In contrast, at least half, and more than 70% of their respective abilities, were lost upon incubation at pH 2 in the absence and presence of pepsin, respectively, for 1 h at 37°C. These results suggest that most of the biological activities of the Fab‐region and Fc‐region of bovine milk IgG can be maintained during processing or storage, and both of the inactivation degrees mainly depend on the stomach condition after oral ingestion of the IgG preparation.