Variation in cooking and eating quality traits in Japanese rice germplasm accessions

The eating quality of cooked rice is important and determines its market price and consumer acceptance. To comprehensively describe the variation of eating quality in 183 rice germplasm accessions, we evaluated 33 eating-quality traits including amylose and protein contents, pasting properties of rice flour, and texture of cooked rice grains. All eating-quality traits varied widely in the germplasm accessions. Principal-components analysis (PCA) revealed that allelic differences in the Wx gene explained the largest proportion of phenotypic variation of the eating-quality traits. In 146 accessions of non-glutinous temperate japonica rice, PCA revealed that protein content and surface texture of the cooked rice grains significantly explained phenotypic variations of the eating-quality traits. An allelic difference based on simple sequence repeats, which was located near a quantitative trait locus (QTL) on the short arm of chromosome 3, was associated with differences in the eating quality of non-glutinous temperate japonica rice. These results suggest that eating quality is controlled by genetic factors, including the Wx gene and the QTL on chromosome 3, in Japanese rice accessions. These genetic factors have been consciously selected for eating quality during rice breeding programs in Japan.     

Effects of atelocollagen gel containing bone marrow-derived stromal cells on repair of osteochondral defect in a dog

To clarify the contribution of autologous transplantation of mesenchymal stromal cells (MSCs), an atelocollagen gel containing or not containing fluorescently-labeled canine MSCs was transplanted into an osteochondral defect which did not repair spontaneously and the histological repair of the defect was compared. Although an early repair of the cartilage was not observed in either defect, the reproduction of subchondral bone was remarkable in the MSCs-implanted defect. Moreover, in 2 weeks after operation, the implanted MSCs were located in the deeper regions of the defect, suggesting the differentiation of osteoblasts. There was a possibility that the movement of the implanted MSCs was due to an increase in intra-articular pressure from postoperative inflammation.     

GM1 gangliosidosis in shiba dogs

A six-month-old shiba dog with a one-month history of progressive motor dysfunction showed clinical signs of a cerebellar disorder, including ataxia, dysmetria and intention tremor of the head. Histopathological and ultrastructural studies revealed distended neurons packed with membranous cytoplasmic bodies throughout the central nervous system. The activities of lysosomal acid beta-galactosidase in its leucocytes and liver were less than 2 per cent of the control levels, and the compound accumulated in the brain was identified as GM1 ganglioside. A sibling which died immediately after birth was shown to have a beta-galactosidase deficiency in the brain and visceral organs. A family study revealed that the sire and dam of the probands were heterozygotes with approximately half of the normal level of beta-galactosidase activity, suggesting an autosomal recessive pattern of inheritance.     

Presence and ontogeny of intestinal and pancreatic phospholipase A2-like proteins in the Red Sea bream,Pagrus major. An immunocytochemical study

We have studied the location and the ontogeny of the digestive enzyme, phospholipase A₂ (PLA₂) immunohistochemically in the adult and larvae/juvenile of the red sea breamPagrus major by using an antiserum against theNaja naja venom PLA₂. The antiserum reacts with at least one enzyme among the PLA₂s purified from the fish hepatopancreas or intestine. Although the reactivities were comparatively low, it labelled zymogen granules of the pancreatic acinar cells and secretory materials of certain epithelial cells in the depths of epithelial crypts in the pyloric caeca of the adult. The immunoreactivities of PLA₂s were investigated in the viscera of larvae and juveniles of the 0 to 85^th day after hatch. In the larvae of the 13^th day, accumulation of PLA₂-positive zymogen granules in the pancreatic acinar cells were first recognized by the immunostaining. The intensity of the labelling subsequently became stronger and dramatically increased between the 20^th and 30^th day. This increase appeared to be one of the physiological changes associated with the transition to a new benthic life as juveniles. Lack of PLA₂ in the pancreas before the 13^th day may suggest the possibility that larvae utilized exogenous PLA₂, inherent in their prey, to digest the phospholipids. On the other hand, no reactivity was found in the intestine until the 85^th day.     

Isolation and characterization of a novel immunomodulatory alpha-glucan-protein complex from the mycelium of Tricholoma matsutake in basidiomycetes

Tricholoma matsutake, a high-class edible mushroom in Japan, has been reported to have excellent biological activities, but difficulty in cultivating the fruit bodies and limited bulk availability have restricted detailed studies. We have developed a method of culturing in tanks, enabling the bulk supply of the mycelia. The preparation (CM6271) exerts modulative effects on the immune competence of mice and rats. In this study, a sodium hydroxide extract of CM6271 was defatted followed by fractionation with a combination of ion exchange chromatography and gel filtration in order to identify the components involved in the expression of the activity, and a single peak fraction (MPG-1) was obtained with reversed phase chromatography. MPG-1 was a glycoprotein (sugar:protein ratio, 94.3:5.7) with a relative molecular mass of 360 kDa, and the sugar moiety contained about 90% glucose. NMR spectra and methylation analysis revealed that the alpha-1,4-linkage was the predominant glucan linkage with alpha-1,6- and alpha-1,2-linkages in the minority. The amino acid composition in the protein moiety was rich in glutamine, alanine, asparagine, leucine, glycine, valine, serine, threonine, isoleucine, and proline. MPG-1 was resistant to degradation with amylase or protease. The oral administration of MPG-1 promoted, in a dose-dependent manner, the recovery of the mouse natural killer cell activity and serum IL-12 level that had been reduced by the loading of restraint stress. The dose of MPG-1 (25 mg/kg) required for the expression of the effect decreases to 1/12 of that of CM6271 (300 mg/kg). Furthermore, MPG-1 formed a complex with TGF-beta1 in vitro, modulating the biological activity of TGF-beta1 by binding to its active form. These results indicate that the mycelium of T. matsutake contains a novel alpha-glucan-protein complex with immunomodulatory activities.     

Grazing of a common species of soil protozoa (Acanthamoeba castellanii) affects rhizosphere bacterial community composition and root architecture of rice (Oryza sativa L.)

We performed a controlled experiment with rice seedlings (Oryza sativa L.) growing in Petri dishes on homogeneous nutrient agar containing a simple rhizosphere food web consisting of a diverse bacterial community and a common soil protozoa, Acanthamoeba castellanii, as bacterial grazer. Presence of amoebae increased bacterial activity and significantly changed the community composition and spatial distribution of bacteria in the rhizosphere. In particular, Betaproteobacteria did benefit from protozoan grazing. We hypothesize that the changes in bacterial community composition affected the root architecture of rice plants. These effects on root architecture affect a fundamental aspect of plant productivity. Root systems in presence of protozoa were characterized by high numbers of elongated (L-type) laterals, those laterals that are a prerequisite for the construction of branched root systems. This was in sharp contrast to root system development in absence of protozoa, where high numbers of lateral root primordia and short (S-type) laterals occurred which did not grow out of the rhizosphere region of the axile root. As a consequence of nutrient release from grazed bacteria and changes in root architecture, the nitrogen content of rice shoots increased by 45% in presence of protozoa. Our study illustrates that interactions over three trophic levels, i.e. between plants, bacteria and protozoa significantly modify root architecture and nutrient uptake by plants.