Measurement of Carbonic Anhydrase Isozyme VI (CA-VI) in Bovine Sera,Saliva, Milk and Tissues

Concentrations of bovine carbonic anhydrase isozyme VI (CA-IV) in bovine serum, saliva, normal milk, colostrum, submandibular gland, liver, and mammary gland were determined. CA-VI was purified from bovine saliva and an antibody to CA-VI was generated. The concentrations of CA-VI in the saliva (7.8 ± 7.9 μg/ml), serum (2.1± 5.7 ng/ml), milk (7.9 ± 12.1 ng/ml), submandibular gland (284.7 μg/g protein), liver (921.0 ± 180.7 ng/g protein) and mammary gland (399.6 ± 191.2 ng/g protein) were determined by ELISA. No seasonal change in CA-VI levels was observed in normal milk. The concentration of CA-VI in colostrum (day 1 post partum) was 119 ng/ml and decreased rapidly by 1 month following birth. Mammary gland contained much smaller amounts than the submandibular gland. CA-VI mRNA was detected in the liver and mammary gland of cow by RT-PCR. The ELISA used in this study proved to be a precise and sensitive method for determining CA-VI concentrations in saliva, serum, milk and tissue specimens from cows. The ELISA may enable the study of changes in CA-VI associated with hereditary or metabolic disorders of the salivary gland, mammary gland and liver using small samples of saliva, serum or milk.     

The developmental ability of vitrified oocytes from different mouse strains assessed by parthenogenetic activation and intracytoplasmic sperm injection

Assessment of the developmental ability of oocytes following freezing and thawing is an important step for optimizing oocyte cryopreservation techniques. However, the in vitro fertilization of frozen-thawed mouse oocytes is often inefficient because of incomplete capacitation of spermatozoa in the absence of surrounding cumulus cells. This study was undertaken to determine whether the oocyte cryopreservation efficiency of different strains of mice could be assessed from the development of oocytes following parthenogenetic activation and intracytoplasmic sperm injection (ICSI). Oocytes were collected from hybrid (C57BL/6 x DBA/2) F1 or inbred (C57BL/6J, C3H/HeN, DBA/2J and BALB/cA) strains and were vitrified in a solution containing ethylene glycol, DMSO, Ficoll and sucrose. In the first series of experiments, oocytes were activated parthenogenetically by Sr(2+) treatment after warming. The oocytes from the inbred strains, but not those of the F1 hybrid, were diploidized by cytochalasin treatment to obtain a sufficient number of blastocysts. In all strains tested, parthenogenetic embryos derived from vitrified oocytes developed into blastocysts at rates between 23 and 68%. In the second series of experiments, vitrified oocytes from each strain were injected with homologous spermatozoa after warming. Normal offspring were obtained from all strains at rates between 5 and 26% per embryo transferred. Thus, the feasibility of oocyte cryopreservation protocols can be assessed easily by in vitro development of parthenogenetic embryos or by in vivo development of ICSI embryos. Moreover, the oocytes of these four major inbred strains of mice can be cryopreserved safely for production of offspring.     

Genetic uniformity of Echinococcus multilocularis collected from different intermediate host species in Hokkaido, Japan

DNA from several isolates of Taenia taeniaeformis and Echinococcus multilocularis were digested with restriction enzymes and hybridized with digoxigenated oligonucleotide probe (CAC)5. Within the six wild isolates of Taenia taeniaeformis from Norway rats in Hokkaido, although several bands were common among isolates, fingerprinting patterns were specific to each isolate. In the case of E. multilocularis, regardless of hosts from which each isolate has been isolated, the five isolates collected from Hokkaido, showed the same fingerprinting pattern. These results indicate that there was very little genetic difference among these isolates. Although the fingerprinting pattern of E. multilocularis from St. Lawrence Is. was similar to that of the Hokkaido isolates, some bands were different from those in the Hokkaido isolates. Echinococcus multilocularis in Hokkaido seems to be closely-related genetically to that from St. Lawrence Is.     

Comparative analysis of diterpene composition in the bark of the hybrid larch F<Subscript>1</Subscript>, <Emphasis Type="Italic">Larix gmelinii</Emphasis> var. <Emphasis Type="Italic">japonica × L. kaempferi</Emphasis> and their parent trees

The diterpene compositions in the bark of branches were investigated for two families of the F₁ hybrid, Kurile larch (Larix gmelinii var. japonica Pilg.) × Japanese larch [Larix kaempferi (Lamb.) Carr.] (hereafter F₁) and their parents clones. 13-Epimanool, larixol, larixyl acetate, 13-epitorulosyl acetate (not detected in L. gmelinii var. japonica), isopimaric acid, abietic acid, dehydroabietic acid, and neoabietic acid were detected. Larixol and abietic acid represented more than 50% of the diterpene content in L. gmelinii var. japonica and L. kaempferi, respectively. Larixol and abietic acid were the predominant diterpene components in the F₁, and the proportions of these diterpenes were between those of the parental species. Therefore, the diterpene compositions in the F₁ were hereditarily infl uenced by their parents. The ratios of labdane, pimarane, and abietane diterpenes suggested that the main diterpene biosynthesis pathway in L. gmelinii var. japonica was from copalyl diphosphate (CDP) to labdane-type diterpenes, and that in L. kaempferi was from CDP to abietane-type diterpenes via pimarane type. Furthermore, linear discriminant analysis suggested that the diterpene contents are effective indices for the discrimination of the hybrid seedlings. Part of this article was presented at the Annual Meetings of the Japan Society for Bioscience, Biotechnology, and Agrochemistry in Kyoto, March 2006, and in Tokyo, March 2007     

Visualization of <Emphasis Type="Italic">Ralstonia solanacearum</Emphasis> cells during biocontrol of bacterial wilt disease in tomato with <Emphasis Type="Italic">Pythium oligandrum</Emphasis>

The biocontrol agent Pythium oligandrum (PO) can suppress bacterial wilt caused by Ralstonia solanacearum (RS) in tomato. To understand the primary biocontrol mechanisms of bacterial wilt by PO, we pretreated tomato plants with sterile distilled water or preinoculated them with PO, followed by inoculation with RS, then observed PO and RS in fixed sections of tomato tissues using a confocal laser-scanning microscope and fluorescence labeling until 14 days after the inoculation with RS. Horizontal and vertical movement of RS bacteria was frequently observed in the xylem vessels of roots and stems of tomato plants (cv. Micro-Tom) that had not been inoculated with PO. In plants that were preinoculated with PO, the movement of RS was suppressed, and bacteria appeared to be restricted to the pit of vessels, a reaction similar to that observed in resistant rootstocks. PO colonization was mainly observed at the surfaces of taproots, the junctions between taproots and lateral roots, and the middle sections of the lateral roots. PO was not observed near wound sites or root tips where RS tended to colonize. However, RS colonization was significantly repressed at these sites in PO preinoculated plants. These observations suggest that the induction of plant defense reactions is the main mechanism for the control of tomato bacterial wilt by PO, not direct competition for infection sites.     

追肥与收获时期对水稻产量和品质影响的研究

通过不同追肥与收获处理对水稻"黄金米"品种的产量、蛋白质含量、直链淀粉含量、食味品质以及外观商品品质的影响进行了研究.结果表明,追肥时期以幼穗形成期最好;追肥量越多,产量越高.蛋白质含量越高,食口品质越差,20 Kg/hm2追肥量(纯N)最适;抽穗后41 d收获食味品质最优;追肥时期、追肥量与直链淀粉含量高低无关.     

Soil formation of new lahar materials derived from Mt. Pinatubo

The early stage of weathering / soil formation processes from new volcanic mudflow (new lahar materials) brought from Mt. Pinatubo was examined. For this purpose, comparative studies on the physical / chemical characteristics of the new lahar materials and soils formed by the deposition of old lahar materials were conducted. Original soils contained less coarse sand, more silt, and clay than the new lahar materials. Increase in the clay content of the original soils reflected the progression of weathering. The occurrence of a higher leaching process of Fe, Ca, and Mg and of a moderate accumulation of organic matter in the original soils was suggested, based on the differences in the soil elemental composition and chemical properties. Values of base saturation and phosphate absorption coefficient (PAC) of the new lahar materials were 388% and 44, while those of all the original soils ranged 15–160% and 55–894, respectively. With the progression of weathering, the PAC value tended to increase gradually while the base saturation value decreased abruptly under the environmental conditions prevailing in the Philippines.     

Evaluation of the Impacts of Marine Salts and Asian Dust on the Forested Yakushima Island Ecosystem, a World Natural Heritage Site in Japan

To elucidate the influence of airborne materials on the ecosystem of Japan??s Yakushima Island, we determined the elemental compositions and Sr and Nd isotope ratios in streamwater, soils, vegetation, and rocks. Streamwater had high Na and Cl contents, low Ca and HCO₃ contents, and Na/Cl and Mg/Cl ratios close to those of seawater, but it had low pH (5.4 to 7.1), a higher Ca/Cl ratio than seawater, and distinct ⁸⁷Sr/⁸⁶Sr ratios that depended on the bedrock type. The proportions of rain-derived cations in streamwater, estimated by assuming that Cl was derived from sea salt aerosols, averaged 81?% for Na, 83?% for Mg, 36?% for K, 32?% for Ca, and 33?% for Sr. The Sr value was comparable to the 28?% estimated by comparing Sr isotope ratios between rain and granite bedrock. The soils are depleted in Ca, Na, P, and Sr compared with the parent materials. At Yotsuse in the northwestern side, plants and the soil pool have ⁸⁷Sr/⁸⁶Sr ratios similar to that of rainwater with a high sea salt component. In contrast, the Sr and Nd isotope ratios of soil minerals in the A and B horizons approach those of silicate minerals in northern China??s loess soils. The soil Ca and P depletion results largely from chemical weathering of plagioclase and of small amounts of apatite and calcite in granitic rocks. This suggests that Yakushima??s ecosystem is affected by large amounts of acidic precipitation with a high sea salt component, which leaches Ca and its proxy (Sr) from bedrock into streams, and by Asian dust-derived apatite, which is an important source of P in base cation-depleted soils.