Comparison of the characters of the plaque-purified viruses from foot-and-mouth disease virus O/JPN/2000

At least two biotypes were observed at the 2nd passage stage after the isolation of Foot-and-mouth disease Virus (FMDV) O/JPN/2000 strain. These 2 types of viruses differed from their plaque phenotypes and were distinguishable by using a monoclonal antibody (MAb) 64G8 that was made for the FMDV O/JPN/2000 strain. One of these 2 biotypes formed small plaque (SP) and with immuno staining showed a positive reaction to MAb 64G8, while the other formed clear large plaque (LP) and did not react with MAb 64G8. The amino acid sequences of the capsid coding region (VP1-VP4) of the SP virus (SPV) and the LP virus (LPV) revealed two substitutions on the 133rd amino acid in VP2, and the 56th amino acid in VP3. These amino acid changes of SPV and LPV are Asn to Asp, Arg to His, respectively. The Arg of the 56th amino acid in VP3 that have been known as critical position of cell culture adapted virus. Only LPV showed high pathogenicity in suckling mice, and its LD(50) was calculated to be about 10(2) TCID(50)/0.1 ml. These results showed that the SPV that existed at the 2nd passage stage from isolation was a low virulence virus, which may suggest why the pathogenicity of O/JPN/2000 did not show clear symptoms in infected cattle.     

Three‐dimensional CT examination of the forefoot and hindfoot of the hippopotamus and tapir during a semiaquatic walking

Semiaquatic walking has resulted in the evolution of functional and morphological changes in various hoofed mammals, such as hippopotamus and Brazilian tapir. The biomechanics of skilful walking in wetlands or at the bottom of a waterbody involve the medio‐lateral opening and closing of the feet to effectively support and stabilize the body on soft ground and to reduce the water resistance during recovery stroke, respectively. We demonstrate that the opening and closing of the feet in hippopotamus and Brazilian tapir are mediated by the adduction and abduction of the most medial and lateral phalanges from the CT examination. The axial toes, metacarpals and metatarsals do not contribute to changes in the width and shape of the feet, unlike the medial and lateral toes. We suggest that this semiaquatic walking motion is derived from the original terrestrial mode of locomotion, in contrast to the highly functional swimming motion using webs or fins in morphologically modified feet and tail. From the present data we demonstrate that semiaquatic locomotion evolved due to the acquisition of adductor–abductor mobility in the phalanges of the most medial and lateral digits, as shown in hippopotamus and Brazilian tapir.     

Functional anatomy of the ocular circulatory system: vascular corrosion casts of the cetacean eye

OBJECTIVE: To examine the functional anatomy of the ocular circulation in four bottlenose dolphins (Tursiops truncatus) and five melon-headed whales (Peponocephala electra). PROCEDURE: Eyes were obtained postmortem from whales that died while in captivity and/or were found beached. Specimens from whales were investigated using scanning electron microscopy (SEM) of vascular corrosion casts and histology. The thermal characteristics of live dolphin eyes were measured using an infrared imaging system. RESULTS: The whale eye receives its primary blood supply from the ophthalmic rete, which extends just behind the eyeball. The ophthalmic rete diverges from the basilar rete and the cervical rete via the posterior thoracic artery. The iris and ciliary processes are supplied by iridic arteries via the major arterial circle that is located around the iris edge. The retinal vessels show the holangiotic type. Choroidal arteries run in parallel arrays so as to interdigitate the densely packed choroidal veins. The venules in the conjunctival fold and palpebral conjunctiva form a well-developed venous plexus. Thermographic examination revealed that the eye shows a substantially higher degree of thermal emission than adjacent skin areas. CONCLUSIONS: The cetacean eye is characterized by a unique vascular pattern and multivessel plexuses, which are quite different from those of terrestrial mammals. This suggests that the ocular vasculature might function as a thermoregulatory system so that the appropriate operating temperature for the photoreceptors can be maintained in a deep and cold aquatic environment. The distinctive plexuses in the orbit might also be for pooling blood in the eye to conserve oxygen during dives. The ophthalmic rete might play a role in a pressure-damping effect on cetacean ocular circulation as well.     

Inheritance of gramine content in barley

The inheritance of gramine indole alkaloid was studied in F1 and F2 generations derived from crosses between wild ( Hordeum vulgare subsp. spontaneum) and cultivated ( H. vulgare subsp. vulgare) barley at adult stage in the field. The means of gramine content were very low in F1s and F2s in April and May. The ratio of progeny containing gramine to those without gramine (near zero or undetectable) fit a mono-genic or di-genic model in F2 generation. However, the content of gramine might be controlled by minor genes in the gramine-containing plants. The direction of dominance was toward lower gramine content. The averages of dominance ( h/d) in F1 and F2 ranged from partial to complete. Broad-sense heritabilities were high (0.70 to 0.77). The usefulness of hybrids for breeding aphid resistance and possibility increasing palatability of grazing pasture for sheep and cattle is discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

An epidemic of parapoxvirus infection among cattle: isolation and antibody survey.

A disease characterized by papules, nodules, vesicles and, rarely, pustules and ulcers on teats was seen among cattle on a farm in Chiba Prefecture, Japan. A virus was isolated by inoculation of fetal bovine lung cell cultures from a vesicle on a teat of an infected cow. The virus was subsequently passaged in fetal bovine lung and muscle cells in which it produced complete cytopathic changes. The virus was identified by physicochemical examinations and electromicroscopic observation as a parapoxvirus. A seroepidemiological survey was performed on antibody to the isolated virus by the agar gel immunodiffusion test. The isolated virus formed a precipitation line which cross reacted with other parapoxviruses isolated previously in Japan. The positive rate was more than 50% among cattle in the Kanto district. The positive rate increased with age. It was suggested that parapoxvirus infection might have already been prevalent among cattle in Japan.     

The functional effect of Gly209 and Ile213 substitutions on lysozyme activity of family 19 chitinase encoded by cyanophage Ma-LMM01

ORF69 in the cyanophage infecting Microcystis aeruginosa, Ma-LMM01, shows homology to the family 19 chitinases where the catalytic domain has structural similarity to lysozyme. Chitinases hydrolyze chitin, a β-1, 4-linked monopolymer of N-acetylglucosamine (GlcNAc); whereas lysozymes hydrolyzes peptidoglycan, alternating β-1, 4-linked copolymers of N-acetylmuramic acid (MurNAc) and GlcNAc. Using amino acid sequence comparison to ORF69, the putative sugar binding residues, Gln162 and Lys165, from the barley chitinase (the model enzyme for the family 19 chitinases) corresponding to subsites −4 and −3 were found to be replaced with Gly209 and Ile213, respectively, in ORF69. To analyze their contribution to substrate binding affinity, ORF69 was cloned into Escherichia coli; and two mutant proteins G209Q and I213K were prepared using site-directed mutagenesis. The wild-type gene product (gp69) showed both lysozyme and chitinase activities. In contrast, the I213K mutant showed a decrease (70%) in lysozyme activity and a significant increase (50%) in chitinase activity; whereas, the G209Q mutant almost completely abolished both enzyme activities. The data suggest the Ile213 residue is involved in recognizing the substrate MurNAc; and Gly209 has significant contribution in chitinase and lysozyme activities for the wild-type gp69.     

Epidemiological study on <Emphasis Type="Italic">Lactococcus garvieae</Emphasis> isolates from fish in Japan

In Japan, Lactococcus garvieae infection has been the main fish disease in aquaculture. Although commercial oral and injectable vaccines have been used to prevent L. garvieae infection in Japan, L. garvieae has been isolated not only from unvaccinated fish but also from vaccinated fish in which immunity induced by vaccination had diminished. In order to obtain epidemiological information on this fish pathogen, we conducted biased sinusoidal field gel electrophoresis (BSFGE) pattern analysis and phage typing of L. garvieae isolates (n = 427) from fish in Japan. These isolates were obtained from 13 different fish species between 1980 and 2007. In the BSFGE analysis, L. garvieae isolates were classified into 17 groups (S1–S17) based on the SmaI digestion patterns and into four groups (A1–A4) based on the ApaI digestion patterns. Phage typing revealed five different phage susceptibility profiles (A–E) in L. garvieae isolates. Since 2005, comparisons of the results of phage typing and BSFGE have indicated the presence of a novel genotype (S16/A4) with phage type E. All the strains belonging to this type showed lincomycin sensitivity.     

Wireless monitoring of blood glucose levels in flatfish with a needle biosensor

A wireless biosensor system was developed for the continuous measurement of blood glucose levels in flatfish. The biosensor was implanted in the interstitial fluid under the scleral surface of the eyeball (EISF) to investigate the relationship between EISF and blood glucose levels. EISF glucose levels were found to be correlated with those in the blood and to be approximately the same as blood glucose levels in the range of 7–25 mg dl⁻¹. A needle-type biosensor was prepared for the continuous EISF glucose monitoring in flatfish. A working electrode was constructed using platinum iridium wire, and glucose oxidase was immobilized to the electrode. The biosensor was inserted into the EISF of flatfish for sensor implantation. A 650-mV potential (vs. Ag/AgCl) was applied by a wireless potentiostat to the working electrode for the amperometric glucose measurement. We investigated whether glucose in the EISF can be determined in vivo. The estimated glucose levels using a one-point calibration method were correlated with actual blood glucose levels. In conclusion, using a wireless biosensor system, we were able to monitor blood glucose levels in flatfish under free-swimming conditions for 16 h.     

External factors that regulate movement in the marine rotifer Brachionus plicatilis

Fisheries Science - There are two types of movement pattern in the Brachionidae (rotifers), swimming and attachment, although the factors that induce a shift between them have not been adequately...     

Variation in understory structure and plant species diversity influenced by silvicultural treatments among 21- to 26-year-old Picea glehnii plantations

We investigated effects of silvicultural treatments (planting and subsequent treatments) on understory structure and plant species diversity in managed Picea glehnii plantations (21–26 years old) in northern Japan. We evaluated the importance of each treatment (machinery site preparation, planting, weeding, and thinning) in 19 plantations, with considerable variation among treatments overall. The understory had 98 vascular plant species; the most dominant species was a dwarf bamboo Sasa senanensis, followed by tree species Abies sachalinensis and Betula ermanii. Multiple regression analyses showed that thinning negatively influenced plant species diversity. Planting density showed a strong positive correlation with density of seedlings (height <20 cm), but few independent variables were correlated with density of saplings (height ≥20 cm and diameter at breast height <1 cm). The negative effect of thinning and the positive effect of planting density seem to be related to the existence or reinitiation of dense cover of Sasa senanensis. We present possible mechanisms of response to treatments to generalize the results. We then suggest ways to improve current treatments to meet the goals of wood production and biodiversity conservation in the region.