The Negative Relationship between Fouling Organisms and the Content of Eicosapentaenoic Acid and Docosahexaenoic Acid in Cultivated Pacific Oysters,Crassostrea gigas

Bivalves serve as an important aquaculture product, as they are the source of essential fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in our diet. However, their cultivation in the wild can be affected by fouling organisms that, in turn, affect their EPA and DHA content. The effects of fouling organisms on the EPA and DHA contents of cultivated bivalves have not been well documented. We examined the effects of fouling organisms on the EPA and DHA contents and condition index of cultured oysters, Crassostrea gigas, in an aquaculture system. We sampled two-year-old oysters from five sites in Shizugawa Bay, Japan, in August 2014. Most of the fouling organisms were sponges, macroalgae, and Mytilus galloprovincialis. A significant negative relationship existed between the DHA content in C. gigas and the presence of sponges and macroalgae. A lower C. gigas EPA content corresponded to a higher M. galloprovincialis fouling mass and a lower C. gigas condition index. This can be explained by dietary competition between C. gigas and M. galloprovincialis for diatoms, which were the main producer of EPA in our study sites. Our findings indicate that fouling organisms likely reduce the EPA and DHA content in cultivated oysters. Therefore, our results suggest that the current efforts to remove fouling organisms from oyster clusters is an effective strategy to enhance the content of EPA and DHA in oysters.     

Distribution of photoperiod-insensitive allele Ppd-A1a and its effect on heading time in Japanese wheat cultivars

The Ppd-A1 genotype of 240 Japanese wheat cultivars and 40 foreign cultivars was determined using a PCR-based method. Among Japanese cultivars, only 12 cultivars, all of which were Hokkaido winter wheat, carried the Ppd-A1a allele, while this allele was not found in Hokkaido spring wheat cultivars or Tohoku-Kyushu cultivars. Cultivars with a photoperiod-insensitive allele headed 6.9–9.8 days earlier in Kanto and 2.5 days earlier in Hokkaido than photoperiod-sensitive cultivars. The lower effect of photoperiod-insensitive alleles observed in Hokkaido could be due to the longer day-length at the spike formation stage compared with that in Kanto. Pedigree analysis showed that ‘Purple Straw’ and ‘Tohoku 118’ were donors of Ppd-A1a and Ppd-D1a in Hokkaido wheat cultivars, respectively. Wheat cultivars recently developed in Hokkaido carry photoperiod-insensitive alleles at a high frequency. For efficient utilization of Ppd-1 alleles in the Hokkaido wheat-breeding program, the effect of Ppd-1 on growth pattern and grain yield should be investigated. Ppd-A1a may be useful as a unique gene source for fine tuning the heading time in the Tohoku-Kyushu region since the effect of Ppd-A1a on photoperiod insensitivity appears to differ from the effect of Ppd-B1a and Ppd-D1a.     

Characterization of canine filaggrin: gene structure and protein expression in dog skin

Background – Filaggrin (FLG) is a key protein for skin barrier formation and hydration of the stratum corneum. In humans, a strong association between FLG gene mutations and atopic dermatitis has been reported. Although similar pathogenesis and clinical manifestation have been argued in canine atopic dermatitis, our understanding of canine FLG is limited. Hypothesis/Objectives – The aim of this study was to determine the structure of the canine FLG gene and to raise anti‐dog FLG antibodies, which will be useful to detect FLG protein in dog skin. Methods – The structure of the canine FLG gene was determined by analysing the publicly available canine genome DNA sequence. Polyclonal anti‐dog FLG antibodies were raised based on the canine FLG sequence analysis and used for defining the FLG expression pattern in dog skin by western blotting and immunohistochemistry. Results – Genomic DNA sequence analysis revealed that canine FLG contained four units of repeated sequences corresponding to FLG monomer protein. Western blots probed with anti‐dog FLG monomer detected two bands at 59 and 54 kDa, which were estimated sizes. The results of immunohistochemistry showed that canine FLG was expressed in the stratum granulosum of the epidermis as a granular staining pattern in the cytoplasmic region. Conclusions and clinical importance – This study revealed the unique gene structure of canine FLG that results in production of FLG monomers larger than those of humans or mice. The anti‐dog FLG antibodies raised in this study identified FLG in dog skin. These antibodies will enable us to screen FLG‐deficient dogs with canine atopic dermatitis or ichthyosis.     

Angiotensin I-converting enzyme-inhibitory peptides obtained from chicken collagen hydrolysate

In this study, collagen extracted from chicken legs (which are the yellow keratin parts containing a nail) was hydrolyzed with various enzymes, and the angiotensin I-converting enzyme (ACE)-inhibitory activity of each hydrolysate was determined. The hydrolysate by treatment with an Aspergillus species-derived enzyme had the highest activity (IC 50 = 260 microg/mL). The fraction of this hydrolysate obtained by ultrafiltration with a molecular-weight cutoff of 3000 Da (low fraction) had a stronger activity (IC 50 = 130 microg/mL) than the fractionated one. This fraction was further fractionated by HPLC, and the peptides in the fraction with high ACE-inhibitory activity were identified. The amino acid sequences of the four peptides were identified using a protein sequencer. These peptides were synthesized to confirm their ACE-inhibitory activities; this showed that peptides with a Gly-Ala-Hyp-Gly-Leu-Hyp-Gly-Pro sequence had the highest activity (IC 50 = 29 microM). When the low fraction was administered to spontaneous hypertensive rats, a decrease in their blood pressure was observed after 2 h of administration, and a significant decrease in blood pressure (-50 mmHg) was observed after 6 h. Moreover, long-term administration studies indicated that the low fraction showed a significant suppression of increased blood pressure.     

Effect of different organic amendments on the resistance and resilience of the organic matter decomposing ability of soil and the role of aggregated soil structure

The effect of organic amendment on the resistance and resilience of the organic matter decomposing activity was compared between soils amended with compost and with chemical fertilizers. The impact of metam sodium disinfection on cellulose-decomposing activity and on the number of nematodes in three types of soils was periodically measured. In an andosol, cellulose-decomposing activity was significantly suppressed by soil disinfection only in the chemically fertilized soil (CF-soil) and not in the soils to which cow manure compost and okara (the residue in tofu production)/coffee compost was added. In a brown lowland soil, cellulose-decomposing activity was significantly suppressed by soil disinfection in the CF-soil, but not in the soils to which higher amounts of cow manure compost and pig manure compost had been added. In a red-yellow soil, cellulose-decomposing activity was significantly suppressed by soil disinfection in all soils, but its resilience was higher in the soils to which cow manure compost or coffee compost was added compared with the CF-soil. Total numbers of nematodes were markedly decreased by soil disinfection in all soils. These results may suggest that the resistance and resilience of cellulose-decomposing activity against soil disinfection were enhanced by organic amendments, while disinfection had fatal effects on soil nematodes. In most of the organically amended soils, the mean weight diameters of aggregates were larger compared with the CF-soils, suggesting that highly structured soil pore networks may provide shelters for the soil microbes responsible for cellulose decomposition against disinfection. This hypothesis was supported by the result that the resistance of cellulose-decomposing activity against soil disinfection decreased when the soil structure was destroyed by grinding in a mortal and pestle.     

Comparative aspects on the role of polypyrimidine tract-binding protein in internal initiation of hepatitis C virus and picornavirus RNAs

We compared the effects of polypyrimidine tract-binding protein (PTB) on hepatitis C virus (HCV genotype IIa), encephalomyocarditis virus (EMCV) and poliovirus internal ribosome entry site (IRES) activities in vitro. It bound strongly to EMCV IRES, but weakly to PV and HCV RNAs. PV IRES showed the strongest dependency to PTB and it showed less than one-tenth of IRES activity after the immuno-depletion of PTB from HeLa S10 lysate with pre-coated anti-PTB IgG beads, comparing to the normal IgG beads-treated S10 lysate. EMCV IRES activity was approximately 40% of that of normal control after PTB depletion. Especially, HCV IRES activity was approximately 95%, and most weekly affected by the depletion of PTB. Repletion of PTB to depleted S10 lysate restored activities of PV and EMCV IRESs. The data suggest that PTB plays an important role in picornaviral IRESs, but not in HCV IRES.     

Identification of c-kit mutations-independent neoplastic cell proliferation of canine mast cells

Gain-of-function mutations in the proto-oncogene c-kit have been considered the molecular mechanism of neoplastic proliferation of mast cells. However, the importance of c-kit gene mutations is not well evaluated in canine mast cell tumors (MCTs). In the present study, we established and characterized a mast cell line, HRMC, derived from a dog with MCT. We also examined c-kit mutations in HRMC cells and assessed an inhibitory effect of a tyrosine kinase inhibitor, STI571, on HRMC cells. HRMC cells had cytoplasmic metachromatic granules, chymase and tryptase, and expressed both KIT and FcepsilonRI on the cell surface. HRMC cells contained histamine and released beta-hexosaminidase through FcepsilonRI cross-linking and calcium ionophore stimulation. Nucleotide sequence analysis demonstrated no mutations in an open reading frame of c-kit cDNA and genomic DNA of the juxtamembrane domain of c-kit in HRMC cells. STI571 did not show any inhibitory effects on the proliferation of HRMC cells. These findings clearly demonstrated the existence of c-kit mutations-independent neoplastic canine mast cell proliferation. The growth factor-independent mast cell line established in this study might be valuable to explore novel mechanisms of c-kit mutations-independent neoplastic proliferation of mast cells in dogs.     

Effect of feeding wood kraft pulp on the growth performance,feed digestibility,blood components,and rumen fermentation in Japanese Black fattening steers

This study aimed to examine the effects of feeding kraft pulp (KP) on the growth performance, feed digestibility, and rumen fermentation of Japanese Black fattening steers. Ten Japanese Black fattening steers (aged 26 months) were randomly divided into control and KP groups. The control group (n = 5) was fed concentrate feed without KP, and the KP group (n = 5) was fed concentrate feed containing 10% KP. Both the groups were provided rice straw as roughage. The experiment was conducted over a period of 12 weeks. There was no significant difference in dry matter intake, daily body weight gain, and nutrient digestibility between both groups. No difference was observed in the ruminal concentrations of volatile fatty acids among the groups. At weeks 8 and 12 after the onset of the experiment, the acetate‐to‐propionate ratio in the ruminal fluid of the KP group was significantly higher than that of the control group. The average daily pH of ruminal fluid and activity of ruminal lipopolysaccharide did not differ between the groups. Our results suggested that the growth performance and feed digestibility in the Japanese Black fattening steers were not influenced by replacing concentrate feed with KP.