Whole‐genome resequencing to identify candidate genes for the QTL for oleic acid percentage in Japanese Black cattle

In our previous study, we detected a QTL for the oleic acid percentage (C18:1) on BTA9 in Japanese Black cattle through a genome‐wide association study (GWAS). In this study, we performed whole‐genome resequencing on eight animals with higher and lower C18:1 to identify candidate polymorphisms for the QTL. A total of 39,658 polymorphisms were detected in the candidate region, which were narrowed to 1993 polymorphisms within 23 genes based on allele differences between the high and low C18:1 groups. We subsequently selected three candidate genes, that is, CYB5R4, MED23, and VNN1, among the 23 genes based on their function in fatty acid metabolism. In each candidate gene, three SNPs, that is, CYB5R4 c.*349G > T, MED23 c.3700G > A, and VNN1 c.197C > T, were selected as candidate SNPs to verify their effect on C18:1 in a Japanese Black cattle population (n = 889). The statistical analysis showed that these SNPs were significantly associated with C18:1 (p < 0.05), suggesting that they were candidates for the QTL. In conclusion, we successfully narrowed the candidates for the QTL by detecting possible polymorphisms located within the candidate region. It is expected that the responsible polymorphism can be identified by demonstrating their effect on the gene's function.     

Effects of urea and trimethylamine-N-oxide on ATPase of requiem shark myofibril and its constituents

ABSTRACT: The effects of trimethylamine- N -oxide (TMAO) on the urea-resistibility of requiem shark myofibrils were investigated, using Ca²⁺- and Mg²⁺-ATPase activities as a parameter. Both activities were hardly changed or activated up to 0.6 M urea. In contrast, the two activities both decreased to less than 50% in the presence of TMAO up to 0.5 M. When measured at a 2 : 1 molar ratio of urea and TMAO, Ca²⁺- and Mg²⁺-ATPase activities were similar to those in the presence of TMAO alone, indicating that TMAO reduced the urea-resistibility of myofibrils. Myosin, the most abundant protein in myofibrils, from requiem shark exhibited the effects of urea and TMAO on its Ca²⁺-ATPase activity, which was primarily similar to those of myofibrils. However, Ca²⁺-ATPase activities in the coexistence of urea and TMAO for actomyosin reconstituted from requiem shark myosin and chicken F-actin were approximately average of those measured independently in the presence of either urea or TMAO alone. Carp myofibrils, reconstituted actomyosin and myosin, which were used as teleost references, all showed a tendency in the effects of urea and TMAO on Ca²⁺-ATPase activities that was similar to those of requiem shark counterparts.     

Measurement system of whole-canopy carbon dioxide exchange rates in grafted cucumber transplants in which scions were exposed to different water regimes using a semi-open multi-chamber

A continuous CO₂ measurement system was developed to monitor the CO₂ exchange rate of the whole canopy of grafted transplants using semi-open multiple chambers. Air heating or cooling and humidification inside a healing box were under control, if needed. To test the system, the gas exchange rate of the cucumber (Cucumis sativus L.) transplants grafted onto pumpkin (Cucurbita maxima cv. ‘New-Shintozwa’) was analysed. During the healing and acclimatisation of the grafted cucumber plants, the air temperature in the box remained constant at night but ranged above 1 °C of a set value under high humidity in daytime. The relative humidity was kept within the set point during the daytime, and it nearly reached 100% at night when not controlled. The cucumber seedlings were exposed to different water stresses before grafting, and the water potentials of each treatment were −0.579 (non-stressed), −0.814 (mildly water-stressed), and −0.870 MPa (strongly water-stressed) on grafting. At the water-stressed scions, leaf expansion was inhibited by 30.9–53.3% compared with the non-stressed scions. Therefore, the gas exchange rates of the strongly water-stressed scions based on the leaf area were decreased to 72.7% compared with the non-stressed scions. After grafting, the apparent photosynthesis of the transplants of all treatments was negative, with higher respiration in the strongly water-stressed scions during the initial period of healing. However, they turned to positive values and exceeded those of the non-stressed scions from three days after grafting. This result provides critical information that the water column is physiologically connected between the stock and scion within two days after grafting. As a result of water stress, the leaf area and dry weight of the transplants in the strongly water-stressed scions were inhibited by 67.5% and 83% compared with the non-stressed scions at the end of acclimatisation. In contrast, the relative growth rate and graft-take of the strongly water-stressed transplants were slightly increased, which suggests that the water stress prior to grafting alleviated the water demand of the scion. This system may provide useful information for diagnosis at the early stage by monitoring the whole canopy's photosynthesis over a long term.     

Immunostimulatory effects of fermented vegetable product on the non-specific immunity of Japanese flounder <Emphasis Type="Italic">Paralichthys olivaceus</Emphasis>

The stimulatory effect of fermented vegetable product (FVP) upon the phagocytic and superoxide generation of leukocytes was studied in the Japanese flounder Paralichthys olivaceus. The phagocytic activity of casein-induced, intraperitoneal leukocytes was investigated and quantified, that is the activity significantly increased (P<0.05 or <0.01) by the addition of FVP beyond 3 mg/kg body weight. Further analysis investigated the effect of FVP on superoxide generation in leukocytes. Established in vitro cytochrome c reduction assay was used to measure superoxide generation; reduced levels of FVP in assay samples had a profound effect on superoxide generation. FVP was also incorporated in commercial diets and fed to Japanese flounder for 4 weeks. The phagocytic activities and superoxide generation of peritoneal induced leukocytes were significantly higher (P<0.05, <0.01) in fish fed the FVP supplemented diet than fish fed the control diet. FVP feeding in fish had a significantly higher (P<0.05) activity of lysozyme than in the control fish.     

Spatial and temporal migration modeling for stock of Pacific saury Cololabis saira (Brevoort), incorporating effect of sea surface temperature

ABSTRACT:   A model is proposed that expresses the spatial and temporal migration pattern for stock of Pacific saury Cololabis saira (Brevoort), in order to investigate the effect of sea surface temperature (SST) on migration rates. Two factors are considered: (i) Saury emigrate to waters of an optimal SST zone; and (ii) saury immigrate from water zone that is extremely cold for saury. Parameters of migration and initial levels of stock are estimated with a maximum likelihood method based on catch per unit effort (CPUE) data for 1995–2001. The best model was selected using Akaike's information criteria. The results suggested that the emigration rate to southern adjacent regions is dependent on the coverage proportion of their waters under some threshold temperatures; 20°C to Doutou and Sanriku, 23°C to Joban and Izu.