Mitochondrial genome diversity in <Emphasis Type="Italic">Beta vulgaris</Emphasis> L. ssp. <Emphasis Type="Italic">vulgaris</Emphasis> (Leaf and Garden Beet Groups) and its implications concerning the dissemination of the crop

Four mitochondrial minisatellites were used to study cytoplasmic diversity in leaf and garden beet germplasm resources. Eleven multi-locus haplotypes were identified, of which one (named mitochondrial minisatellite haplotype 4, hereafter min04) was associated with male-sterile Owen cytoplasm and two others (min09 and min18), with a normal fertile cytoplasm. European leaf beet germplasm exhibited the greatest haplotype diversity, with min09 and min18 predominating. In North African leaf beet accessions, only these two haplotypes were observed, making it likely that North African accessions were descended from European genotypes. The prevalence of min18 was also noted in leaf beet from the Middle East and western Asia. Such a pattern contrasts with that found in east Asian leaf beet where the two haplotypes were extremely rare. The geographical structure of the mitochondrial haplotypes allowed us to infer possible dissemination pathways of leaf beet. Additionally, we showed that mitochondrial genome diversity was low in garden beet germplasm, with min18 being highly predominant. An explanation of this limited diversity may lie in the geographically restricted origin of as well as relatively short cultivation histories of garden beet.     

Relationship between the first and second crops and estimation of genetic parameters of the second crop on the nutritive value of timothy (<Emphasis Type="Italic">Phleum pratense</Emphasis> L.)

Improvement of the nutritive value of timothy (Phleum pratense L.) through breeding should result in enhanced livestock productivity. This study investigated the extent of genotype × crop interaction (G × C) between the first and second crops, and the extent of genotype × year interaction (G × Y) and narrow-sense heritability (h _N²) of the second crop of the nutritive value of timothy. Twenty-six clones were used to evaluate these interactions in 2007 and 2008, and 17 clones and their half-sib progeny were used to evaluate the h _N² in 2010 in Kunneppu, Japan by analyzing their nutritive value. The content of water-soluble carbohydrate (WSC) was significantly correlated between the two crops in 12 clones with many internode elongation stems (IES) in the second crop and the 2 years, with non-significant effects of G × C in these clones and G × Y. However, the low-digestible fiber (Ob) content and the ratio of Ob to organic cell wall showed weak to medium correlations between the two crops, regardless of IES ratio or the elapsed time of 2 years, with significant effects shown for the two interactions. The h _N² of the three traits was medium to high. These results suggest that, in the second crop, selections for WSC content through the first crop in genotypes with many IES in the second crop, and under multiple environments in other traits are potentially useful; and that recurrent selection which utilizes an additive genetic variance is likely to be effective for the three traits.     

Formation of methanethiol and dimethyl disulfide in crushed tissues of broccoli florets and their inhibition by freeze-thawing

The formation of methanethiol and dimethyl disulfide in crushed, homogenized, and frozen-thawed tissues of broccoli florets was investigated. These volatile sulfur compounds were produced in crushed florets, but their formation was inhibited in frozen-thawed tissues. Only dimethyl disulfide was formed in homogenized tissues. High pH treatment triggered the release of dimethyl disulfide in frozen-thawed tissues and also enhanced the action of cysteine sulfoxide lyase in all disrupted tissues. Methyl methanethiosulfinate and methyl methanethiosulfonate were not detected in crushed florets; thus, the favored mechanism for the formation of methanethiol and dimethyl disulfide is the chemical disproportionation of methanesulfenic acid. In contrast, the formation of dimethyl disulfide in frozen-thawed and homogenized tissues occurs from the chemical disproportionation of methyl methanethiosulfinate that was detected in these tissues. The inhibition of dimethyl disulfide production during freeze-thawing must be caused by a sudden drop in the pH of the tissue, adherence of dimethyl disulfide on the tissue surfaces, and weakening of the cysteine sulfoxide lyase activity under acidic conditions.     

Antioxidant activity of dodecyl gallate

Dodecyl (C12) gallate exhibits both potent chain-breaking and preventive antioxidant activity. The pyrogallol moiety is responsible for both activities. Dodecyl (lauryl) gallate prevents generation of superoxide radicals by xanthine oxidase, and this activity comes from its ability to inhibit the enzyme. The inhibition kinetics analyzed by Lineweaver-Burk plots found that dodecylgallate is a noncompetitive inhibitor for the generation of superoxide anion. Dodecyl gallate also inhibits formation of uric acid. The inhibition kinetics analyzed by Lineweaver-Burk plots found that dodecyl gallate is a competitive inhibitor for this oxidation. Mitochondrial lipid peroxidation induced by Fe(III)-adenosine 5'-diphosphate/reduced nicotinamide adenine dinucleotide was inhibited by dodecyl gallate while its parent compound, gallic acid, did not show this inhibitory activity. Dodecyl gallate protected mitochondrial functions and human red blood cells against oxidative stresses, but gallic acid showed little effect. The hydrophobic dodecyl group is largely associated with the preventive antioxidative activity.     

Zinc effects on soil microflora and glucose metabolites in soil amended with 14C-glucose

Summary The effects of zinc added to a diluvial sandy clay loam soil on its microflora and the metabolic products of amended glucose in the soil were investigated, and its influences on both biological and chemical turnover are discussed.Changes in the soil microflora were followed by counting the microbes and measuring their contributions to soil respiration. The transformations of ¹⁴C-glucose products were traced in five divided fractions.Amended glucose was readily assimilated into microbial tissues and transformed to metabolites in the control soil. Within the initial 24 h of the incubation, most of the glucose was decomposed and about 40% of the substrate evolved as carbon dioxide. This primary metabolism was attributed to the bacterial population, and the subsequent secondary metabolism was associated with fungal growth rather thanbacteria. On the other hand, zinc (1000 g/g) added as chloride prolonged the primary metabolism of glucose and a large part of the incubation period for 96 h was occupied by this metabolism, which was mostly dependent on the fungal population. Viable bacterial number noticeably within the first 24 h of the incubation. During the course of the subsequent incubation, however, this number increased and the selection for zinc tolerance was suggested.     

Annual Changes in Day-length,Temperature, and Circulating Reproductive Hormones in Thoroughbred Stallions and Geldings

Changes in follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin, immunoreactive(ir)-inhibin, testosterone, estradiol-17β, and insulin-like growth factor (IGF)-I in Thoroughbred stallions along with changes in prolactin secretion in geldings were studied. The correlations of day-length with changes in the concentrations of these hormones were also studied. Five stallions and thirteen geldings were employed to draw blood samples in monthly basis and radioimmunoassay was performed to measure these hormones. All hormones showed a seasonal pattern, the levels being highest during the breeding season and lowest during the winter months. Most of the hormones were at their highest concentration during the month of April, the mid of spring in northern hemisphere. The concentration of circulating IGF-I also demonstrated seasonality, the peak lying on the month of April. The plasma concentration of prolactin also increased during the breeding season. This phenomenon was similar both in stallions and geldings although geldings had lower concentration than that of stallions. The changes in concentration of prolactin in stallions and geldings correlated more towards the day-length than towards the temperature. These results clearly indicate the seasonality of pituitary and gonadal hormones of Thoroughbred stallions, the activity being highest during the month of April and May of the breeding season.     

Fermentation characteristics and microorganism composition of total mixed ration silage with local food by‐products in different seasons

Total mixed ration (TMR) silage in different seasons was prepared with apple refuse, orchardgrass hay, orchardgrass silage, corn silage and a commercial compound feed in Tohoku, Japan, and with tofu cake, brewers' grains, tall fescue hay, Sudangrass hay, timothy hay, alfalfa hay and a commercial compound feed in Shikoku, Japan, respectively, and their fermentation quality and microorganism composition were evaluated. In Tohoku, the TMR silage in spring, autumn and winter displayed poor quality, with pH value above 4.7, and the harmful microorganisms such as escherichia, yeasts and molds were detected even after 60 days of ensiling; but the TMR silage in summer was well preserved and the escherichia were too few to count after 7 days of ensiling. In Shikoku, the TMR silage in all seasons was well preserved, with low pH, high lactic acid contents, and escherichia, yeasts and molds were consistently at or below the detectable numbers after 7 days of ensiling. The results showed that the TMR silage could not produce sufficient lactic acid to improve silage quality under low‐temperature conditions. Therefore, it is necessary to develop preparation techniques of promoting the lactic acid fermentation for TMR silage in cold seasons.     

Xenografting of gonadal tissues into mice as a possible method for conservation and utilization of porcine genetic resources

In vitro production of embryos, including in vitro maturation, fertilization of oocytes and their subsequent culture to the embryo stage, has become the most popular method of studying gametogenesis and embryogenesis in pigs. As well as their utility for basic studies, these procedures now enable us to generate viable embryos and offspring as a means of conserving genetic resources and rare animal breeds. Recently, more advanced technologies such as xenografting of gonadal (testicular and ovarian) tissues into immunodeficient experimental animals have been developed. In combination with in vitro embryo production techniques, this approach may provide many benefits. We have been carrying out studies to acquire basic information about the application of this method to porcine species, and to improve the existing techniques. Recently, we obtained oocytes from ovarian tissue xenografted and grown in nude mice that had the capacity to be fertilized and the ability to develop into early‐stage embryos. We also obtained spermatozoa from the xenografted testicular tissues and injected them intracytoplasmically into in vitro‐matured oocytes to produce piglets. Here we discuss the further possibilities of conservation and utilization of porcine gonadal tissue by xenografting into immunodeficient mice.     

Calcitonin receptor binding in the hen anterior pituitary during an oviposition cycle

The equilibrium dissociation constant (K_d) and the maximum binding capacity (B_max) of calcitonin (CT) receptor in the plasma membrane of the anterior pituitary in hens were examined by Scatchard analysis of specific binding of ¹²⁵I‐labeled chicken CT. Values of K_d and B_max of CT receptor were smaller in laying hens than in non‐laying hens. A decrease in the K_d and B_max value of CT receptor was observed in the anterior pituitary after the injection of estradiol‐17β and progesterone into nonlaying hens, but not changed after the injection of 5α‐dihydrotestosterone. During an oviposition cycle, the K_d and the B_max value decreased 3 h before oviposition. In non‐laying hens, neither the K_d nor the B_max value changed during a full day period. The present study suggests that the CT action on the anterior pituitary may increase 3 h before oviposition by the effect of estradiol‐17β and progesterone in laying hens.