Precise, simple screening for resistance in potato varieties to common scab using paper pots     

Akira Kobayashi  Shigeo Naito  Yuki O. Kobayashi  Shogo Tsuda  Akiko Ohara-Takada  Motoyuki Mori 《Journal of General Plant Pathology》2005,71(2):139-143

Resistance to common scab pathogen Streptomyces turgidiscabies of seven potato varieties was compared in the field with a newly developed paper pot method. Seedlings raised in soil in paper pots containing inocula at 1 × 10³ to 10⁷cfu/g soil were transplanted into a scab-free field and grown for 3 months. The disease severity of the seven varieties in the field trials differed in iteration and from year to year, even though their resistance levels were approximately similar at the expected levels. With the paper pot method, the seven varieties had different resistance levels, which were almost completely consistent with the results of the field trials, at more than 1 × 10⁵cfu/g soil. Significant differences in disease severity between resistant and susceptible varieties were observed (P = 0.05) for 2 years, and the resistance level of the varieties was elucidated.  相似文献   

Sexual mating preferences in vitro and in planta among Japanese isolates of Phytophthora infestans     

Kiyotaka Gotoh  Seishi Akino  Takako Kiyoshi  Shigeo Naito 《Journal of General Plant Pathology》2005,71(1):29-32

The sexual preferences of Japanese isolates of Phytophthora infestans were determined by mating on agar, in broth, or in plants. The influence of their sexual preference was confirmed in the host tissues. Three wild-type isolates and a -glucuronidase (GUS) transformant were co-cultured to identify the origin of antheridia and oogonia. Japanese A1 isolate had a unique sexual preference compared with foreign isolates. It produced self-fertile oospores with about 40% of total gametangia but tended to form antheridia on V-8 agar medium. In addition, oospores were formed in plants, but their sexual preference could not be reflected in vitro.  相似文献   

Nucleocapsid-like structures of Ebola virus reconstructed using electron tomography     

Noda T  Aoyama K  Sagara H  Kida H  Kawaoka Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(3):325-328

Electron tomography (ET) is a new technique for high resolution, three-dimensional (3D) reconstruction of pleiomorphic macromolecular complexes, such as virus components. By employing this technique, we resolved the 3D structure of Ebola virus nucleocapsid-like (NC-like) structures in the cytoplasm of cells expressing NP, VP24, and VP35: the minimum components required to form these NC-like structures. Reconstruction of these tubular NC-like structures of Ebola virus showed them to be composed of left-handed helices spaced at short intervals, which is structurally consistent with other non-segmented negative-strand RNA viruses.  相似文献   

Fine surface structure of bovine acrosome-intact and reacted spermatozoa observed by atomic force microscopy     

Saeki K  Sumitomo N  Nagata Y  Kato N  Hosoi Y  Matsumoto K  Iritani A 《The Journal of reproduction and development》2005,51(2):293-298

The atomic force microscope (AFM) provides nanometer resolution, topographic data of the natural surface structure of materials. We studied the topology of the surface structure of bovine sperm heads during the acrosome reaction by AFM. In addition, we numerically analyzed the areas of the median sagittal plane of the sperm heads. Bovine frozen-thawed spermatozoa were washed, capacitated by heparin, and incubated with lysophosphatidylcholine (LPC) to induce the acrosome reaction, smeared on a cover glass, air-dried, and observed with AFM using the dynamic force (tapping) mode. AFM analysis of spermatozoa showed the clear surface structure of acrosomes, equatorial segments, postacrosomal regions and necks. Although AFM images of spermatozoa capacitated by heparin had complete acrosomes, most spermatozoa treated with LPC had no acrosomal caps as shown by AFM. These observations coincided with those obtained by light microscopy after staining with naphthol yellow S and erythrosin B. Furthermore, numerical analysis of AFM images indicated that areas of the median sagittal plane of the anterior portions of acrosome-reacted sperm heads (2679 +/- 616 pixels) were approximately 40% less than those of intact heads (4535 +/- 174 pixels, P<0.05). These results indicate that AFM can usefully observe and numerically analyze the fine surface structures of bovine spermatozoa.  相似文献   

Aberrant development of mammary glands, but precocious expression of beta-casein in transgenic females ubiquitously expressing whey acidic protein transgene     

Iwamori T  Oosawa M  Nukumi N  Kano K  Sudo K  Naito K  Tojo H 《The Journal of reproduction and development》2005,51(5):579-592

It has been suggested that whey acidic protein (WAP) may function as a protease inhibitor. However, the actual function of WAP remains obscure. We investigated the histological development of the mammary glands of transgenic mice ubiquitously expressing WAP and CAG/WAP transgene. Ubiquitous expression of WAP induced aberrant development of the lobular alveoli of the mammary glands: mammary alveoli that were either aberrantly large or small in size increased in number in the developing mammary glands of these transgenic females during pregnancy and lactation. The expression of beta-casein was precociously induced in the mammary glands of the transgenic females during early pregnancy and accompanying this was a histological observation that abnormally developed lobular alveoli filled with milk proteins appeared in the mammary glands of transgenic females during early pregnancy. However, during lactation, the development of mammary glands was impaired in transgenic females. To investigate the possible paracrine action of WAP associated with mammary gland aberration, we transplanted the mammary tissue of CAG/EGFP transgenic females into the fat pad of virgin CAG/WAP transgenic females and initiated pregnancy by mating. The development of mammary tissue transplanted to the recipient was histologically examined on day 3 of lactation. The results revealed that the development of grafted mammary tissues was impaired in a manner similar to that of the mammary glands of CAG/WAP transgenic females, indicating that the inhibitory effect of WAP acts via a paracrine mechanism. In vitro experiments using HC11 cells with forced expression of exogenous WAP demonstrated the inhibitory function of WAP on proliferation of mammary epithelial cells.  相似文献   

Environmental factors influencing sporocarp formation in <Emphasis Type="Italic">Typhula ishikariensis</Emphasis>     

Akira?KawakamiEmail author  Naoyuki?Matsumoto  Shigeo?Naito 《Journal of General Plant Pathology》2004,70(1):1-6

Environmental factors influencing sporocarp formation in Typhula ishikariensis were studied under controlled conditions. Sporocarp formation in T. ishikariensis was divided into two stages: stipe elongation from the sclerotium and fertile head development at the tip of the stipe. Factors required for each stage differed. At the stipe elongation stage, low temperature (10°/5°C; day/night) and high humidity were important, but light was not required. In contrast, at the fertile head stage, light and moderate day length (8h/day) were essential. Fertile heads developed at 46µEm^–2s^–1; and high intensity (137µEm^–2s^–1) did not suppress development. Moreover, adding unsterilized soil to the sea sand medium accelerated sporocarp formation. These findings imply that the sclerotium of T. ishikariensis recognizes several physical factors for sporocarp formation. Sporocarps of T. ishikariensis developed within 4 weeks after incubation under optimal conditions. The sporocarp produced basidiospores, and differential mating incompatibility was confirmed among monokaryons derived from basidiospores produced under artificial conditions. This method should be useful for obtaining monokaryons for genetic studies of T. ishikariensis.  相似文献   

Migration of primordial germ cells isolated from embryonic blood into the gonads after transfer to stage X blastoderms and detection of germline chimaerism by PCR     

Naito M  Sano A  Harumi T  Matsubara Y  Kuwana T 《British poultry science》2004,45(6):762-768

1. The present study was carried out to determine whether primordial germ cells isolated from embryonic blood can enter the bloodstream and successfully migrate to the germinal ridges of recipient embryos after transfer to stage X blastoderms, and also whether they can differentiate into blood cells, as is suggested in mice. 2. Primordial germ cells were transfected in vitro by lipofection and then transferred to stage X blastoderms. The introduced GFP gene was efficiently expressed in the gonads of 6-d incubated embryos. 3. Freshly collected primordial germ cells were transferred to stage X blastoderms. The fate of the transferred primordial germ cells was traced by detecting the single nucleotide polymorphism in the D-loop region of the mitochondrial DNA in White Leghorn and Barred Plymouth Rock chickens used in this study. The transferred donor primordial germ cell-derived cells were detected in the gonads, but not in the blood cells, of 17-d incubated embryos by PCR. 4. This procedure for primordial germ cell manipulation could provide a novel method of producing germline chimaeric chickens. 5. In conclusion, our findings indicate that primordial germ cells isolated from embryonic blood can migrate to the germinal ridges of recipient embryos after being transferred to stage X blastoderms. Although these transferred primordial germ cells differentiated into germ cells, no differentiation into blood cells was observed.  相似文献   

Cloning of bovine MAIL and its mRNA expression in white blood cells of Holstein cows     

Yamaji D  Kitamura H  Kimura K  Matsushita Y  Okada H  Shiina T  Morimatsu M  Saito M 《Veterinary immunology and immunopathology》2004,98(3-4):175-184

Molecule possessing ankyrin-repeats induced by lipopolysaccharide (MAIL) is known as an IkappaB protein induced after administration of bacterial lipopolysaccharide (LPS) to mice. In the present study, we cloned bovine MAIL cDNA and examined its mRNA expression in white blood cells isolated from Holstein cows. Bovine MAIL had more than 80% amino acid identities with murine and human MAILs, highly conserved ankyrin-repeat motifs and PEST-like sequences. Bovine MAIL mRNA was undetectable in isolated peripheral white blood cells, but rapidly induced (<1h) after stimulation by LPS and lipid A in vitro in a dose-dependent manner. The lipid A-induced MAIL mRNA expression was found in polymorphonuclear cells, monocytes/macrophages and total lymphocytes, but not in T-lymphocytes. MAIL mRNA was also induced in vivo in peripheral blood leukocytes of cows after intramammary injection of Escherichia coli derived from coliform mastitis. Thus, bovine MAIL, as rodent MAILs, is induced by inflammatory stimuli in specific immune cells in vitro and in vivo, suggesting a role in inflammatory responses to bacterial infection in cattle.  相似文献   

Molecular cloning, chromosomal location, and biological activity of porcine interleukin-21     

Muneta Y  Kikuma R  Uenishi H  Hoshino T  Yoshihara K  Tanaka M  Hamashima N  Mori Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(3):269-275

A pig interleukin-21 (IL-21) cDNA was successfully cloned and sequenced from porcine peripheral blood lymphocytes (PBL) stimulated with 10 microg/ml concanavalin A (ConA), 10 microg/ml phytohemagglutinin P (PHA), 50 ng/ml phorbol 12-myristate 13-acetate (PMA), and 0.5 microg/ml anti-porcine CD3 antibody for 48 hr. The open reading frame of the porcine IL-21 cDNA is 459 base pairs in length and encodes 152 amino acids. The predicted amino acid sequence of the porcine IL-21 shows 86.2%, 77.7%, and 58.4% identity to the bovine, human, and murine IL-21, respectively. The porcine IL-21 gene was mapped to porcine chromosome 8 (8q22-->q23) by means of fluorescence in situ hybridization and radiation hybrid mapping, where the porcine IL-2 gene had been mapped nearby. The recombinant porcine mature IL-21 expressed by E. coli induced dose-dependent proliferation and IFN-gamma production from a human NK cell line, NK0. The porcine IL-21 identified in this study will be helpful for the enhancement of innate immune responses of pigs.  相似文献   

Developmental competence of porcine blastocysts produced in vitro   总被引：1，自引：0，他引：1  

Kikuchi K 《The Journal of reproduction and development》2004,50(1):21-28

The establishment of in vitro embryo production (IVP) system in pigs enables us to generate viable embryos with a quality equal to that of in vivo derived embryos. This technology contributes not only to developments in reproductive physiology and agriculture but also to biotechnologies for producing cloned or genetically modified pigs. The birth of piglets from in vitro matured and fertilized embryos at the two- to 4-cell stage was first achieved about 10 years ago, but it was only quite recently that piglets were produced after the transfer of IVP blastocysts. This improvement to the blastocyst stage of the in vitro culture system after in vitro maturation and fertilization can be expected to play a part in the development of an advanced IVP system. Here, we discuss the developmental ability of porcine embryos produced by our improved IVP system and the utilization of this technique in the new biotechnology.  相似文献