Diversity in nicotinamide-adenine dinucleotide requirement for the growth of different strains of Mycoplasma synoviae

The type strain WVU 1853 and field strains SG, N26 and A642 of Mycoplasma synoviae were examined for their requirement for nicotinamide-adenine dinucleotide (NAD) for in vitro growth. All the strains grew and could be repeatedly passaged in Frey broth medium supplemented with filter-sterilised NAD. In modified Frey broth medium from which NAD was omitted and broth medium for which the supplements including yeast extract and NAD were autoclaved, only strains N26 and A642 could be grown and passaged. The growth curves of strain N26 determined in broth media with and without NAD were similar. These results indicated that there are differences in NAD-requirement for in vitro growth among strains of M synoviae.     

Exploration of factors determining milk production by Holstein cows raised on a dairy farm in a temperate climate area

In this study, we examined factors that affected milk production by cows raised in a temperate climate area. We conducted this study on a large dairy farm containing approximately 2000 Holstein cows, located in a temperate climate area. We collected 7803 calving records for 4069 cows from 2012 to 2016. We then assessed the effect of hot weather on milk yield by examining three climate factors: season, maximum temperature (MAX), and the temperature and humidity index (THI). We found that increases in heat stress caused linear decreases in milk yield (P?<?0.05). Additionally, the effects of the three climate factors on milk yield varied depending on cow parity and days open (P?<?0.05). Thus, management procedures should consider cow parity and lactating stage to minimize the negative effects of heat stress on milk production. We also found that the lowest Akaike information criterion value was obtained in our model when using THI for 305-day milk yield. This suggests that THI is a more accurate variable for evaluating heat stress than MAX or season.

     

Transfer of the Rsv3 locus from ‘Harosoy’ for resistance to soybean mosaic virus strains C and D in Japan

Resistance to soybean mosaic virus (SMV) is imperative for soybean (Glycine max (L.) Merr.) production in the Tohoku region. Molecular markers for SMV resistance were previously reported for U.S. SMV strains, but they cannot be applied because of the differences in strain classification between Japan and the U.S. A U.S. variety ‘Harosoy’ has been used mainly as a donor of resistance to SMV strains C and D in a Japanese breeding program, resulting in resistant varieties such as ‘Fukuibuki.’ Because ‘Harosoy’ harbors the Rsv3 gene conferring resistance to the virulent SMV strain groups, G5 through G7, it appears that the Rsv3 gene confers resistance to strains C and D. In this study, we introduced resistance to the two strains from ‘Fukuibuki’ into a leading variety ‘Ohsuzu’ by recurrent backcrossing with marker-assisted selection. All lines selected with markers near Rsv3 showed resistance to the strains, suggesting that the Rsv3 locus is responsible for the resistance. Three years of trials showed that one of the breeding lines, ‘Tohoku 169,’ was equivalent to ‘Ohsuzu’ with respect to agricultural characteristics such as seed size, maturity date, and seed yield, except for the SMV resistance.     

Development and evaluation of microsatellite loci for <Emphasis Type="Italic">Gynochthodes boninensis</Emphasis> (Rubiaceae), a woody climbing plant endemic to the Bonin (Ogasawara) Islands,Japan

Microsatellite loci were developed for Gynochthodes boninensis, an endemic climbing plant in the Bonin Islands. Using a Roche 454 GS Junior next-generation sequencer, 158 microsatellite loci were designed. Of the 48 microsatellite loci tested, 37 were successfully amplified and 25 were polymorphic in two populations of G. boninensis. For the 25 polymorphic loci, the mean expected heterozygosities per locus were 0.303 in the Chichijima Island population and 0.310 in the Hahajima Island population, respectively. There was no evidence of linkage disequilibrium in either population, but one locus showed significant deviation from Hardy–Weinberg equilibrium in one population. The microsatellite loci developed in this study will be useful for future studies of population genetics of G. boninensis. In particular, because this species is androdioecious (males and hermaphrodites coexist), characterizing the species gene flow is crucial to understanding the evolution and maintenance of this rare sexual system.     

Differences in nitrogen economy of temperate trees

Twenty-four temperate tree species were classified into three groups based on cluster analysis of relative growth rate, nitrogen concentration, nitrogen-production efficiency, nitrogen-distribution ratio and nitrogen-use efficiency as follows: Group I (Asteridae and Rosidae), Group II (Dilleniidae and Hamamelidae) and Group III (Coniferopsidae). Relative growth rate (RGR) was high in Group II, moderate in Group I and low in Group III. The regression coefficient for the relationship between RGR and leaf nitrogen concentration was higher in Group II than in Group I, and no relationship was observed in Group III. Parameter analysis of RGR indicated that RGR per unit leaf nitrogen was important for all three groups, but that the allocation of nitrogen to leaves was particularly important in Groups I and II. The ratio of dark respiratory rate (R) to net photosynthetic rate (A) was higher in Group I than in Group II. Neither A nor R was measured in the Group III species. A linear relationship was observed between leaf nitrogen concentration and A in Group II, but this relationship was not evident in Group I.     

Vertical, horizontal and azimuthal variations in leaf photosynthetic characteristics within a Fagus crenata crown in relation to light acclimation

An understanding of spatial variations in gas exchange parameters in relation to the light environment is crucial for modeling canopy photosynthesis. We measured vertical, horizontal and azimuthal (north and south) variations in photosynthetic capacity (i.e., the maximum rate of carboxylation: Vcmax), nitrogen content (N), leaf mass per area (LMA) and chlorophyll content (Chl) in relation to relative photosynthetic photon flux (rPPF) within a Fagus crenata Blume crown. The horizontal gradient of rPPF was similar in magnitude to the vertical gradient of rPPF from the upper to the lower crown. The rPPF in the north quadrant of the crown was slightly lower than in the south quadrant. Nitrogen content per area (Narea), LMA and Vcmax were strictly proportional to rPPF, irrespective of the vertical direction, horizontal direction and crown azimuth, whereas nitrogen content per dry mass, Chl per area and photosynthetic capacity per dry mass (Vm) were fairly constant. Statistical analyses separating vertical trends from horizontal and azimuthal trends indicated that, although horizontal and vertical light acclimation of leaf properties were similar, there were two significant azimuthal variations: (1) Vcmax was lower in north-facing leaves than in south-facing leaves for a given Narea, indicating low photosynthetic nitrogen-use efficiency (PNUE) of north-facing leaves; and (2) Vcmax was lower in north-facing leaves than in south-facing leaves for a given LMA, indicating low Vm of the north-facing leaves. With respect to the low PNUE of the north-facing leaves, there were no significant azimuthal variations in leaf CO2 conductance from the stomata to the carboxylation site. Biochemical analysis indicated that azimuthal variations in nitrogen allocation to ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and in nitrogen allocation between carboxylation (Rubisco and other Calvin cycle enzymes) and light harvesting machinery (Chl pigment-protein complexes) were not the main contributor to the difference in PNUE between north- and south-facing leaves. Lower specific activity of Rubisco may be responsible for the low PNUE of the north-facing leaves. Anatomical analysis indicated that not only high leaf density, which is compatible with a greater fraction of non-photosynthetic tissue, but also thick photosynthetic tissue contributed to the low Vm in the north-facing leaves. These azimuthal variations may need to be considered when modeling canopy photosynthesis based on the Narea-Vcmax or LMA-Vcmax relationship.     

Effects of estimation length on parameter estimates of geometric Brownian motion for log price dynamics

We investigated an effect of the estimation length of the time-series data on the parameter estimates of geometric Brownian motion for log prices. This is to examine how much the estimates vary depending upon the estimation length of the data for the simulation purpose of stochastic modeling. Using the monthly time-series data for akamatsu, sugi, and hinoki from January 1975 to December 2000, our analysis shows that the longer the estimation length, the more stable the estimated value of the drift coefficient and the volatility coefficient of geometric Brownian motion become, implying less variability in the estimates needed for the simulation analysis. On the other hand, the shorter estimation length would tend to reflect such a sudden change in the data as the oil shock or the short-term decreasing or increasing tendency, which results in the large degree of variability in parameter estimates. This stems from the fact that the long estimation length regards a short-term price changes as an intrinsic part of price volatility. These results imply that when conducting a scenario analysis under stochastic environments, for the shorter estimation length, the wider range of parameter settings should be incorporated into the analysis.     

Factors enabling Epinotia granitalis (Lepidoptera: Tortricidae) overwintered larvae to escape from oleoresin mortality in Cryptomeria japonica trees in comparison with Semanotus japonicus (Coleoptera: Cerambycidae)

The factors involved in the successful escape of overwintered larvae of Epinotia granitalis from host oleoresin in the phloem of Cryptomeria japonica were studied. The mortality, period, and body weight of E. granitalis overwintered larvae while feeding on the phloem of C. japonica were compared with the same parameters for Semanotus japonicus larvae. The seasonal fluctuation in the ability of C. japonica to form traumatic resin canals in the phloem was also assessed. The oleoresin mortality of E. granitalis was low compared with that of S. japonicus. Although both species started feeding on approximately the same date in spring, the feeding period of E. granitalis was only about 24 days, showing that E. granitalis faced the danger of host oleoresin for a shorter period than S. japonicus. The larval weight of E. granitalis was consistently greater than that of S. japonicus through the phloem-feeding period of E. granitalis, and the growth rate was also higher in E. granitalis, suggesting that E. granitalis had a better ability to avoid host oleoresin. These results demonstrated that not only the feeding habits, that is, the tendency of a single larva to feed at several sites, but also the shorter feeding period and larger body size were probably the important factors facilitating escape of E. granitalis from host oleoresin mortality. Furthermore, the ability of C. japonica to form traumatic resin canals increased after the starting date of larval feeding in spring. Because E. granitalis finished feeding before the culmination of the ability of C. japonica to form traumatic resin canals, it was likely that the shorter feeding period was the most important factor in enabling E. granitalis to escape from mortality by host oleoresin.     

Technique for screening immune-enhancing polysaccharides in food using 1,25-dihydroxyvitamin D3-differentiated HL60 cells

A technique for screening immune-enhancing polysaccharides in food using the phagocytotic activity of 1,25-dihydroxyvitamin D3 (VD3)-differentiated HL60 cells is presented. HL60 cells, a human acute promyelocytic cell line, can differentiate along the monocytic lineage following exposure to VD3 or phorbol-12-myristate-13-acetate (PMA). For differentiated cells along the monocytic pathway, HL60 cells were maintained in RPMI 1640 medium supplemented with 10% FBS and 120 nM VD3 for more than 1 week. VD3-differentiated HL60 cells were seeded into 48-well plates, YG-labeled microspheres and polysaccharides were added and mixed using a plate shaker at 1100 rpm for 30 s, and then the mixture was incubated overnight at 37 degrees C in 5% CO2. The cells were fixed with 2% formaldehyde and resuspended in phosphate-buffered saline. The rate of phagocytosis was measured with a flow cytometer. VD3-differentiated cells but not non- and PMA-differentiated cells resulted in an elevation of phagocytic activity by various immune-enhancing polysaccharides in foods.     

Incidence of canine glaucoma with goniodysplasia in Japan : a retrospective study

The incidence of primary and secondary glaucoma in dogs was investigated. A total of 1244 dogs received ophthalmologic examinations, including tonometry and gonioscopy. Goniophotographs were taken using a goniolens to evaluate the iridocorneal angle (ICA) as well as pectinate ligament (PL). The anterior width of the ciliary cleft and the total distance from the origin of the PL to the anterior corneal surface were measured from the goniophotographs. Glaucoma was diagnosed based on the cupping of the optic nerve head, clinical signs, ocular changes, and high IOP, and it was synchronized with gonioscopic grades to differentiate between primary and secondary glaucoma. We investigated 1244 dogs of 29 breeds, including the mixed breed; among these, glaucoma was diagnosed in 127 dogs (162 eyes). Of 162 eyes, primary glaucoma was diagnosed in 129 eyes and secondary glaucoma in 33 eyes. Shiba Inu dogs (42 dogs, 33%) showed the highest incidence of glaucoma, followed by Shih-Tzu (21 dogs, 16.5%). Furthermore, all the glaucomatous Shiba Inu dogs had primary glaucoma with abnormal ICA grades and dysplastic PLs. The findings of our study reveal that the Shiba Inu breed in Japan may have a hereditary predisposition to glaucoma.