Microstructure of a Brassica rapa genome segment homoeologous to the resistance gene cluster on Arabidopsis chromosome 4

Genome evolution is a continuous process and genomic rearrangement occurs both within and between species. With the sequencing of the Arabidopsis thaliana genome, comparative genetics and genomics offer new insights into plant biology. The genus Brassica offers excellent opportunities with which to compare genomic synteny so as to reveal genome evolution. During a previous genetic analysis of clubroot resistance in Brassica rapa, we identified a genetic region that is highly collinear with Arabidopsis chromosome 4. This region corresponds to a disease resistance gene cluster in the A. thaliana genome. Relying on synteny with Arabidopsis, we fine-mapped the region and found that the location and order of the markers showed good correspondence with those in Arabidopsis. Microsynteny on a physical map indicated an almost parallel correspondence, with a few rearrangements such as inversions and insertions. The results show that this genomic region of Brassica is conserved extensively with that of Arabidopsis and has potential as a disease resistance gene cluster, although the genera diverged 20 million years ago.     

Canine intestinal mast cell tumor with c-kit exon 8 mutation responsive to imatinib therapy

A canine intestinal mast cell tumor with splenic metastasis was treated with imatinib. The intestinal and metastatic tumor masses markedly decreased following treatment although the clinical response was short lasting. A c-kit internal tandem duplication mutation, c.1250_1261dup, which causes an insertion of four amino acids in KIT, was identified in cDNA isolated from the tumor cells. The phosphorylation status of the mutant KIT and the effect of imatinib on its phosphorylation were examined using 293 cells transfected with c-kit carrying the c.1250_1261dup mutation. This mutation caused ligand-independent phosphorylation of KIT, which was suppressed by imatinib. Inhibition of constitutively activated mutant KIT with imatinib could underlie the tumor response in this dog.     

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.     

Immunochromatographic assay for simple and rapid detection of <Emphasis Type="Italic">Satsuma dwarf virus</Emphasis> and related viruses using monoclonal antibodies

A simple and rapid immunochromatographic assay (ICA) to detect Satsuma dwarf virus (SDV) was developed using colloidal gold conjugates of anti-SDV monoclonal antibodies. Of six homogenization buffers tested, 0.1 M citrate buffer (pH 7.0) gave the best results for the ICA. In the ICA, addition of 0.1% thioglycolic acid in the homogenization buffers that have been widely used in enzyme-linked immunosorbent assays (ELISA) was deleterious to the reaction because of undesirable coagulation of the colloidal gold. ICA using the anti-SDV monoclonal antibodies was 8 times and 16 times more sensitive than double antibody sandwich-ELISA and ICA using the anti-SDV polyclonal antibody, respectively. The analysis is complete in only 15 min. Furthermore, ICA using the anti-SDV monoclonal antibodies could also detect SDV-related viruses.     

Genetic and molecular analysis of the restoration of fertility ( Rf ) genes for Ogura male-sterility from a Japanese wild radish ( Raphanus sativus var. hortensis f. raphanistroides Makino)

Ogura male-sterile cytoplasm is one of the most extensively studied cytoplasms in Brassicaceae. In this study, in order to gain better understanding of the variation and evolution of the restoration of the fertility (Rf) gene for Ogura male-sterile cytoplasm, the nucleotide sequence of the orf687 homologue in the Japanese wild radish (Raphanus sativus var. hortensis f. raphanistroides Makino) was analyzed using an F₂ population made with a cross between a Japanese wild radish plant containing the Rf gene and ‘Uchiki-Gensuke’ (a maintainer of Ogura-male sterility). Segregation of male-fertile/-sterile plants in the F₂ generation suggested that another unidentified Rf gene unlinked to orf687 exists in the Japanese wild radish. The genotype of orf687 was determined for each F₂ plant by Southern hybridization with an orf687 gene probe, mismatch-specific endonuclease digestion of PCR products, and direct sequencing of a PCR product. Genotyping revealed that some fertility-restored plants are homozygotic for the ‘Uchiki-Gensuke’ type orf687 allele, supporting the idea that another gene different from orf687 also functions as an Rf gene for Ogura male-sterility. Protein analysis using an antibody raised against the Ogura-specific ORF138 protein suggests a mechanism of fertility restoration by the unidentified Rf similar to that by orf687. Sequence analysis of orf687 from a Japanese wild radish plant and ‘Uchiki-Gensuke’ revealed that both orf687 regions encode a mitochondrially-targeted protein consisting of 687 amino acids with 16 PPR motifs. Comparison of the deduced amino acid sequences with those of the known orf687 sequences from ‘Yuan hong’ and ‘Kosena’ containing Rf and recessive one (rf), respectively, showed that three unique amino acid replacements are present in ORF687 of the Japanese wild radish. Two of the three replacements, that from lysine to isoleucine at position 232 and from asparagine to asparate at position 240, confer negative charges to the protein. Since the Rf of ‘Yuan hong’ was reported to have a unique replacement that confers a negative charge to ORF687 (from asparagine to aspartate at position 170), it is proposed that the amino acid replacements conferring a negative charge to ORF687 are important for determining the status of the Rf/rf gene.     

Epidemiological study of Kabuto Mountain virus,a novel uukuvirus,in Japan

Kabuto Mountain virus (KAMV), the new member of the genus Uukuvirus, was isolated from the tick Haemaphysalis flava in 2018 in Japan. To date, there is no information on KAMV infection in human and animals. Therefore, serological surveillance of the infection among humans and wild mammals was conducted by virus-neutralization (VN) test and indirect immunofluorescence assay (IFA). Sera of 24 humans, 59 monkeys, 171 wild boars, 233 Sika deer, 7 bears, and 27 nutria in Yamaguchi Prefecture were analyzed by VN test. The positive ratio of humans, monkeys, wild boars, and Sika deer were 20.8%, 3.4%, 33.9% and 4.7%, respectively. No positive samples were detected in bears and nutria. The correlation coefficients between VN test and IFA in human, monkey, wild boar, and Sika deer sera were 0.5745, 0.7198, 0.9967 and 0.9525, respectively. In addition, KAMV was detected in one pool of Haemaphysalis formosensis ticks in Wakayama Prefecture. These results indicated that KAMV or KAMV-like virus is circulating among many wildlife and ticks, and that this virus incidentally infects humans.     

Freshwater migration and feeding habits of juvenile temperate seabass <Emphasis Type="Italic">Lateolabrax japonicus</Emphasis> in the stratified Yura River estuary,the Sea of Japan

Juvenile temperate seabass Lateolabrax japonicus were sampled along the Yura River estuary from April to July 2008 to determine their distribution and feeding habits during migration within a microtidal estuary. Throughout the sampling period, juvenile seabass were distributed not only in the surf zone, but also in the freshwater zone, and they were particularly abundant in areas with aquatic vegetation in the freshwater zone. This distribution pattern suggests that the early life history of the temperate seabass depends more intensively on the river (freshwater) than previously considered. Small juveniles in the freshwater zone fed on copepods and chironomid larvae and upon reaching a standard length (SL) of approximately 20 mm did they fed on mysids. In contrast, juveniles (approx. 17–80 mm SL) in the surf zone fed mainly on mysids.     

Relationship between body length, processed-meat length and seasonal change in net processed-meat yield of Japanese mantis shrimp Oratosquilla oratoria in Tokyo Bay

ABSTRACT:   There is concern regarding a possible decrease in the minimum exploitable size of the mantis shrimp Oratosquilla oratoria in Tokyo Bay, coincident with a decline in stock size. To assess this problem, the condition factor, the relationship between body length and processed-meat length, and the estimated body length for each market size category were investigated and compared monthly. The condition factor was lowest in spring and peaked in winter. The difference between body length and meat length was higher in summer and winter than in spring and autumn, suggesting that a high condition factor does not result in an increased net yield of processed meat. The annual mean minimum exploitable size in the present low-stock-size condition did not differ from the minimum exploitable size measured during a high-stock-size period (11-cm body length). However, the minimum exploitable size changed seasonally, which coincided with seasonal change in the net processed-meat yield. Exploitation during the season when net meat yield is high would result in increase of the large-sized meat products of high price.     

Inhibition of Lipopolysaccharide-Induced Inflammatory Signaling by Soft Coral-Derived Prostaglandin A2 in RAW264.7 Cells

Lipopolysaccharide (LPS) is a component of the outer membrane of Gram-negative bacteria and causes inflammatory diseases. We searched MeOH extracts of collected marine organisms for inhibitors of LPS-induced nitric oxide (NO) production in RAW264.7 cells and identified prostaglandin A₂ (PGA₂) as an active compound from the MeOH extract of the soft coral Lobophytum sp. PGA₂ inhibited the production of NO and reduced the expression of inducible NO synthase (iNOS) in LPS-stimulated RAW264.7 cells. Although short preincubation with PGA₂ did not inhibit LPS-induced degradation and resynthesis of IκBα, the suppressive effect of PGA₂ was observed only after a prolonged incubation period prior to LPS treatment. In addition, PGA₂-inhibited NO production was negated by the addition of the EP4 antagonist L161982. Thus, PGA₂ was identified as an inhibitor of LPS-induced inflammatory signaling in RAW264.7 cells.     

Pre‐emptive meloxicam for postoperative analgesia in piglets undergoing surgical castration

ObjectiveTo investigate the effect of preoperative meloxicam administration on postoperative stress and pain induced by surgical castration in piglets.Study designProspective, blinded, randomized clinical trial.AnimalsOne hundred and eighty male piglets of <1 week of age.MethodsCastration was performed on 150 piglets which had received either an intramuscular injection of 0.4 mg kg^?1 meloxicam or a placebo 10–30 minutes before the procedure. Blood cortisol and ACTH concentrations were determined at 30 minutes post–castration and haptoglobin was measured at 24 hours post–castration. Presence or absence of foreleg movements, hind leg movements, urine or faeces emission, tremors or other body movements were recorded during the castration procedure. Scores for presence or absence of prostration, tremors, tail movements and isolation were recorded at 30 minutes, and at 1, 2, 4 and 24 hours post–castration and combined in a global behaviour score (GBS). Blood samples were taken from a further 30 piglets which did not undergo castration.ResultsMean blood cortisol and ACTH concentrations at 30 minutes post–castration were both significantly lower in the meloxicam group than in the placebo group (p ≤ 0.01). The mean haptoglobin concentration at 24 hours was not significantly reduced (p = 0.178). The distribution of the GBS during castration was similar in both groups. There were significant differences in the GBS after castration at both 2 and 4 hours post–castration with a greater proportion of piglets in the meloxicam group showing no behavioural alterations (82.7%versus 68.0% at both time points). The score distribution was similar in both groups at 30 minutes, 1 and 24 hours after castration.Conclusion and clinical relevanceThis study suggests that pre–emptive administration of meloxicam is able to produce some postoperative analgesia after surgical castration of young piglets.