Interspecific hybrids betweenAllium fistulosumandAllium schoenoprasumreveal carotene-rich phenotype

Interspecific hybridization is an effective method to generate a new crop that gains available functions in a short time. Interspecific hybrids (2n= 16) betweenAllium fistulosumL. (2n= 16) andAllium schoenoprasumL. (2n= 16) were produced by reciprocal crossings through ovary culture, but the hybrids were much fewer in the combination usingA. schoenoprasumas a seed plant. All the hybrids have eight long chromosomes originated fromA.fistulosumand eight short chromosomes originated fromA. schoenoprasum. In addition, the hybridity was confirmed by randomly amplified polymorphic DNA (RAPD) analysis and cleaved amplified polymorphic sequence (CAPS) analysis of the rDNA internal transcribed spacer (ITS) region. The interspecific hybrids showed a vigorous growth habit; their foliage was slightly bloomy and deep green. The hybrids did not form bulbs, but rather propagated vegetatively by tillering. Carotene contents of the hybrids and both parents were quantified using high-performance liquid chromatography (HPLC). The contents of all edible parts of the hybrids were approximately seven times higher than those of either parent. These results indicate that the hybrid is a new and carotene-rich vegetable ofAlliumspecies.     

Kinetics of diarrhetic shellfish poisoning toxins,okadaic acid,dinophysistoxin-1, pectenotoxin-6 and yessotoxin in scallops <Emphasis Type="Italic">Patinopecten yessoensis</Emphasis>

ABSTRACT:   Four toxins, okadaic acid (OA), dinophysistoxin-1 (DTX1), pectenotoxin-6 (PTX6), and yessotoxin (YTX), all associated with diarrhetic shellfish poisoning (DSP), were administered via syringe to Scallops Patinopecten yessoensis and their distribution in the hepatopancreas, adductor muscle, and combined other tissues (mantle, gill, gonad) was analyzed by liquid chromatography-mass spectrometry. Toxins exclusively remained in the hepatopancreas irrespective of the injection site, adductor muscle or hepatopancreas. When injected into hepatopancreas, OA, DTX1, and YTX were metabolized to 7- O -palmitoylOA, 7- O -palmitoylDTX1 and 45-hydroxyyessotoxin (45OH-YTX), respectively. Such metabolic changes were insignificant when toxins were injected into the adductor muscle. The residual ratio for each toxin in the hepatopancreas was less than 20%. Mortalities of scallops treated with PTX6 were lower than those treated with other toxins.     

An H5N1 highly pathogenic avian influenza virus that invaded Japan through waterfowl migration

In 2010, an H5N1 highly pathogenic avian influenza virus (HPAIV) was isolated from feces of apparently healthy ducks migrating southward in Hokkaido, the northernmost prefecture of Japan. The H5N1 HPAIVs were subsequently detected in domestic and wild birds at multiple sites corresponding to the flyway of the waterfowl having stopovers in the Japanese archipelago. The Hokkaido isolate was genetically nearly identical to H5N1 HPAIVs isolated from swans in the spring of 2009 and 2010 in Mongolia, but less pathogenic in experimentally infected ducks than the 2009 Mongolian isolate. These findings suggest that H5N1 HPAIVs with relatively mild pathogenicity might be selected and harbored in the waterfowl population during the 2009-2010 migration seasons. Our data provide "early warning" signals for preparedness against the unprecedented situation in which the waterfowl reservoirs serve as perpetual sources and disseminators of HPAIVs.     

Rapid identification of hemoplasma species by palindromic nucleotide substitutions at the GAAA tetraloop helix in the specificity domain of ribonuclease P RNA

We examined secondary structures of the ribonuclease P RNA sequences obtained from DNA databases, and identified a determinative prototype of the P12 helix peculiar to each species of hemoplasmas. This key structure will provide a rapid means for species identification of these uncultivable pathogens without making a phylogenetic tree based on alignments of nucleotide sequences. This procedure based on palindromic nucleotide substitutions at the stem portion of the P12 helix provide clear information such as the level of heterogeneity within a species, the relatedness between species, or facilitating the characterization and clustering of specific strains. In conclusion, the PNS analysis is based on the evaluation of only the strategic and highly conserved genomic region in the specificity domain of RNase P RNA.     

Reproductive phenotypes in mice with targeted disruption of the 20alpha-hydroxysteroid dehydrogenase gene

In the corpus luteum of rats and mice, 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD) catalyzes the conversion of progesterone to a biologically inactive metabolite, 20alpha-dihydroprogesterone (20alpha-OHP). The reduction of progesterone by 20alpha-HSD is believed to be important for functional luteolysis in these rodent species. In addition to the corpus luteum, expression of 20alpha-HSD has been demonstrated in tissues such as the placenta, endometrial epithelia, and fetal skin, although the roles it plays in the latter tissues remain to be determined. To determine the contribution of 20alpha-HSD to functional luteolysis and to the rodent reproductive system more generally, we generated a strain of mice with targeted disruption of the 20alpha-HSD gene. In the 20alpha-HSD-/- mice we obtained, which lacked the genomic region essential for catalytic reaction, neither 20alpha-HSD activity in the corpus luteum nor an increase in the serum concentrations of 20alpha-OHP during pseudopregnancy or pregnancy was detected. The durations of the estrous cycle, pseudopregnancy, and pregnancy were significantly prolonged in the 20alpha-HSD-/- mice, although the serum progesterone levels decreased to levels low enough for delivery of pups at term of pregnancy. In addition, the number of pups, especially live pups, was markedly decreased in the 20alpha-HSD-/- mice. These findings suggest that the role of 20alpha-HSD in functional luteolysis is relatively minor but that it is involved in the survival of newborn mice.     

Histopathological evaluation of the ocular-irritation potential of shampoos,make-up removers and cleansing foams in the bovine corneal opacity and permeability assay

The bovine corneal opacity and permeability (BCOP) assay is an alternative method to the in vivo Draize eye test in rabbits for evaluating eye irritation in vitro. Here, we compared the numerical results of the BCOP assay with the corresponding histopathology for three different corneas for each test substance, including commercially available shampoos, make-up removers and cleansing foams that contained surfactants and other ingredients. The histopathological score was defined based on the severity of lesions in the corneal epithelium. The histopathological findings and scores of the three sections for each test substance were comparable. The in vitro irritancy score (IVIS) generally corresponds to the corneal irritant potential of the test substances assigned on the basis of the histopathological findings in this study. In the present study, we characterized the histopathology of the corneal epithelium and stroma and especially showed that the corneal epithelial injury caused by test substances might be important in assessment of test substances that are mild eye irritants (category 2B) as classified by the United Nations (UN) Globally Harmonized System of Classification and Labelling of Chemicals (GHS), as corneal lesions suggestive of classification into category 2B were localized on the border between the corneal epithelium and stroma, which contained cell elements related to assessment of prognosis of an in vivo eye injury. Histopathological assessment might be useful in predicting in vivo ocular irritation, particularly for test substances with an IVIS >3.1 but ≤25 that are classified as mild irritants (category 2B) according to the UN GHS.     

Inhibitory potential of metabolites produced by Cercospora sp. strain ME202 isolated from Trifolium incarnatum against anthracnose caused by Colletotrichum orbicular

Chemical fungicides are mainly used to control Colletotrichum orbiculare, but this fungal pathogen usually develops resistance to the pesticides. Natural compounds are therefore desirable for controlling C. orbiculare. Here, a culture filtrate (CF) from ME202, a fungal strain isolated from Trifolium incarnatum in Shimane Prefecture in 2020, was tested in vitro and found to inhibit conidial germination of C. orbiculare. The inhibitory compound in ME202-CF was soluble in ethyl acetate. The ethyl acetate extract of ME202-CF (ME202-ECF) significantly inhibited in vitro conidial germination of C. orbiculare in a dose-dependent manner and lesion formation on cucumber leaves. The inhibitory compounds were heat stable at 40–121 °C and molecular mass?≥?500 and ≥?1000 Da. Thin layer chromatography–bioautography of ME202-ECF showed that the compounds inhibiting C. orbiculare growth had an Rf of 0.81 and 0.91. Furthermore, ME202 was found to be a member of the genus Cercospora through sequence analysis of the internal transcribed spacer and 5.8 S rDNA. These results suggest that secondary metabolites of Cercospora spp., such as ME202, can be used to develop new fungicides against anthracnose.

     

Carotenoid Profile of Edible Japanese Seaweeds: An Improved HPLC Method for Separation of Major Carotenoids

An improved multi-step gradient reverse phase high performance liquid chromatography (HPLC) method to simultaneously separate major carotenoids from natural as well as food samples was developed. Quantitative profiling of carotenoid compounds was carried out on three edible brown seaweeds (Sargassum horneri, Cystoseira hakodatensis, and Undaria pinnatifida) and three red seaweeds (Gracilaria vermiculophylla, Grateloupia asiatica, and Grateloupia livida). Fucoxanthin (Fx) was detected in all the brown seaweeds with quantities (mg g^?1 dry weight [dwt]) ranging from 1.3 ± 0.3 in C. hakodatensis to 2.4 ± 0.1 in S. horneri. U. pinnatifida, commonly known as wakame, had a Fx content of 2.3 ± 0.1 mg g^?1 dwt. In the case of red seaweeds, zeaxanthin (Zx) was the major carotenoid, and G. vermiculophylla had the highest Zx content (80.2 μg g^?1 dwt) among the red seaweeds apart from small amounts of Fx (9.1 μg g^?1 dwt). Similarly, the other two species of red seaweeds, G. asiatica and G. livida, contained (μg g^?1 dwt) lutein (Lut), Fx, and Zx as the major carotenoids (G. asiatica: Lut 10.4, Fx 1.5, Zx 1.1; G. livida: Lut 9.3, Fx 3.5, Zx 1.0). The results suggest the usefulness of edible varieties (barring wakame) of seaweeds as dietary sources of carotenoids.     

Involvement of HLK effectors in Ralstonia solanacearum disease development in tomato

A multigene family encoding HLK effectors is well conserved in all Ralstonia solanacearum strains. The HLK family contains three paralogous members. We constructed single, double, and triple deletion mutants of hlk genes in R. solanacearum strain OE1-1 and characterized HLK effectors by comparing the phenotypes of the strains. HLK effectors exhibited some functional redundancy. While the triple deletion mutant was significantly impaired in virulence on tomato and multiplied less efficiently than the wild type in the leaves, the mutant was as virulent as the wild type on eggplant and tobacco.