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1.
Maiko Kaneko Etsuro Yoshimura Naoko K. Nishizawa Satoshi Mori 《Soil Science and Plant Nutrition》2013,59(3):701-712
To clarify the mechanism(s) involved in the short-term inhibition of root elongation by AI, we monitored the morphological changes of barley roots by digital microscopy. Within 30 min after exposure to 37 µM AI, the surface of the root epidermis in the region of a distance of 1.5 mm from the root tip became rough and began to show signs of damage. After 38 min, callose was rapidly excreted from the junction between the root cap and the root epidermis, and formed a spherical lump approximately 60 µm in diameter. The fine structure of the callose deposits on the root surface was analyzed by low-vacuum scanning electron microscopy. After 50 min, there was a significant increase in the callose contents in the distal 0.6 mm part. At the same time, root elongation stopped completely. Fluorescence staining indicated that callose was localized on the surface of the cell elongation area (the elongation zone of primary roots and root hairs), but not on the surface of the meristem. The root growth reduction associated with AI treatment may be due to the use of sugar substrates for callose formation instead of cellulose formation. 相似文献
2.
Suzu Sakao Takafumi Fujimoto Terumasa Kobayashi Goro Yoshizaki Etsuro Yamaha Katsutoshi Arai 《Fisheries Science》2009,75(4):993-1000
Diploid gametes generated with tetraploid animals are a stepping stone to improving chromosome manipulation techniques. However,
artificially induced tetraploid individuals generally die soon after hatching. Diploid gametes could be induced by in vivo
cultures of tetraploid primordial germ cells (PGCs) through germ-line chimera. In the present study, characteristics of PGCs
were studied in inviable tetraploid masu salmon, Oncorhynchus masou. Histological observation of tetraploid embryos revealed that the same or smaller numbers of PGCs were observed and they
migrate into the genital ridges as did diploid PGCs during gonadogenesis. By whole-mount in situ hybridization using vasa messenger RNA (mRNA), 4–35 vasa-positive signals were detected in a pair of genital ridges of tetraploids. By cytological
observation of genital ridge cell suspensions, several large round cells were observed, some of which extended pseudopodia.
They also contained large nuclei and round granules in their cytoplasm, characteristics of PGCs. As the results suggest that
inviable artificial tetraploids have PGCs, we expect to achieve diploid gamete production through surrogate propagation and
tetraploid fish production. 相似文献
3.
We recently generated transgenic mice expressing a soluble form of porcine nectin-1 (PHveCIg) showing remarkable resistance to pseudorabies virus (PRV) infection. Nectin-1, also known as herpesvirus entry mediator C (HveC), is an alphaherpesvirus receptor that binds to virion glycoprotein D (gD). In order to evaluate the level of resistance to PRV infection induced by the expression of PHveCIg in the transgenic mice, the protective effects of vaccinated and transgenic mice were directly compared. Mice were immunized with a live vaccine, through intraperitoneal injection of PRV strain Begonia (an attenuated vaccine strain deleted for gE and thymidine kinase genes) at 4 weeks before challenge. The vaccinated and transgenic mice were challenged with 10LD(50), 20LD(50) or 50LD(50) of PRV strainYS-81 via intranasal route. In the vaccinated mice, no protection was observed in the challenges with 20LD(50) and 50LD(50). Only two out of six vaccinated mice survived in the challenge with 10LD(50). In contrast, four transgenic mouse lines showed significant resistance to PRV infection, although the survival rates varied in the challenge with each viral dose. These results demonstrate clearly the high potential of transgenic strategy in control of pseudorabies. 相似文献
4.
Kawakami Y Saito T Fujimoto T Goto-Kazeto R Takahashi E Adachi S Arai K Yamaha E 《Journal of animal science》2012,90(2):495-500
The feasibility of cryopreserving common carp (Cyprinus carpio) primordial germ cells (PGC) by vitrification of whole embryos at the 22- to 28-somite stage was investigated. Green fluorescent protein (GFP)-labeled PGC were cooled rapidly using liquid nitrogen after exposure to a pretreatment solution containing 1.5 M cryoprotectant (ethylene glycol or dimethyl sulfoxide, 30 or 50 min) and a vitrification solution containing 3 M cryoprotectant and 0.5 M sucrose (5, 10, 20, or 30 min). Embryonic cells that were pretreated for 30 min and vitrified for 20 min with ethylene glycol had the greatest rate of survival of embryonic cells (68.6%; P < 0.01), an optimal highest percentage of viable PGC (73.8 to 74.9%; P < 0.05), and no evidence of ice formation after thawing. The vitrified/thawed PGC were transplanted into blastula-stage embryos from goldfish (Carassius auratus). The PGC maintained their motility and moved to the gonadal ridge of the host embryo. Thus, the combination of vitrification and transplantation to produce germ-line chimeras is a powerful tool for the artificial production of next-generation offspring. 相似文献
5.
Satoshi?KusudaEmail author Nobuhisa?Koide Hiloshi?Kawamula Tetsuo?Teranishi Jun?-Ichiro?Nakajima Etsuro?Yamaha Katsutoshi?Arai Hiromi?Ohta 《Fisheries Science》2005,71(2):293-298
To develop a suitable cryopreservation diluent for spermatozoa of the endangered Sakhalin taimen Hucho perryi, all possible combinations of cryoprotectants (glycerol, dimethyl sulfoxide [DMSO], methanol) and extenders (fetal bovine
serum [FBS], 300 mM glucose solution [GS], artificial seminal plasma for masu salmon) were examined by observing sperm motility
10 s after thawing. Spermatozoa cryopreserved with diluents such as mixtures of 10% glycerol plus 90% FBS, 10% DMSO plus 90%
FBS, and 10% methanol plus 90% GS showed the highest motility. The maximal post-thaw motility was observed at 10% among all
concentrations (0, 5, 10, 15 and 20%) of these three cryoprotectants. No significant difference among three diluents was observed
in motility at 10 s. Mixtures of 10% glycerol plus 90% FBS, 10% DMSO plus 90% FBS, and 10% methanol plus 90% GS are suitable
cryopreservation diluents for Sakhalin taimen spermatozoa. 相似文献
6.
Jie Dong Masaru Murakami Takafumi Fujimoto Etsuro Yamaha Katsutoshi Arai 《Fisheries Science》2013,79(6):935-941
Silver crucian carp Carassius auratus langsdorfii comprises a diploid-polyploid complex in wild Japanese populations. Bisexually reproducing diploids are sympatrically distributed with gynogenetically developing triploids and tetraploids. Triploid and tetraploid males are very rare among Japanese silver crucian carp due to their gynogenetic reproduction. We examined the genetic characteristics of progeny that arose in a tank by natural spawning of a tetraploid silver crucian carp pair. The ploidy status of 120 samples randomly collected from these progeny was determined to be tetraploid by DNA content flow cytometry. DNA fingerprints from a random amplified polymorphic DNA assay indicated that almost all the progeny examined had genotypes identical to the maternal tetraploid female with no paternally derived fragments. Selected specimens’ cytogenetic analyses revealed that the progeny examined had tetraploid chromosome numbers, categorized into 40 metacentric, 80 submetacentric, and 80 subtelocentric or telocentric chromosomes, which were arranged into quartets and six supernumerary microchromosomes. Fluorescence in situ hybridization signals were detected in four homologous chromosomes in all analyzed metaphases prepared from diploid goldfish specimens. Contrary, tetraploid silver crucian carp gave eight rDNA signals. These results suggest that gynogenetic development in eggs spawned by tetraploid females should be triggered by tetraploid males’ homospecific sperm. 相似文献
7.
Gaku Kanno Takahito Yamaguchi Hideki Kishimura Etsurou Yamaha Hiroki Saeki 《Fish physiology and biochemistry》2010,36(3):637-645
Trypsin from the pyloric ceca of masu salmon (Oncorhynchus masou) cultured in fresh water was purified by a series of chromatographies including Sephacryl S-200, Sephadex G-50 and diethylaminoethyl
cellulose to obtain a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS–PAGE) and native PAGE.
The molecular mass of the purified trypsin was estimated to be approximately 24,000 Da by SDS–PAGE. The enzyme activity was
strongly inhibited by phenylmethylsulfonyl fluoride, soybean trypsin inhibitor, and N
α
-p-tosyl-l-lysine chloromethyl ketone. Masu salmon trypsin was stabilized by calcium ion. The optimum pH of the masu salmon trypsin
was around pH 8.5, and the trypsin was unstable below pH 5.0. The optimum temperature of the masu salmon trypsin was around
60°C, and the trypsin was stable below 50°C, like temperate-zone and tropical-zone fish trypsins. The N-terminal 20 amino acid sequence of the masu salmon trypsin was IVGGYECKAYSQPHQVSLNS, and its charged amino acid content was
lower than those of trypsins from frigid-zone fish and similar to those of trypsins from temperate-zone and tropical-zone
fish. In the phylogenetic tree, the masu salmon trypsin was classified into the group of the temperate-zone fish trypsin. 相似文献
8.
9.
Said AW Usui T Shinya K Ono E Ito T Hikasa Y Matsuu A Takeuchi T Sugiyama A Nishii N Yamaguchi T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(4):541-544
A sero-epidemiological survey of human and equine H3 influenza A virus infections in dogs and cats using the hemagglutination inhibition (HI) and neuraminidase inhibition (NI) tests was conducted. Serum samples were collected from 582 dogs and 237 cats in Japan during the periods 2002-2008 and 1997-2008, respectively. Although no HI antibodies against equine H3 virus were detected, 9 (3.8%) from cats and 12 (2.1%) from dogs were HI-positive against human H3 virus. Only one serum each from dogs and cats was NI-positive against N2 virus. These findings suggest that although equine H3 influenza virus infections have not been prevalent in companion animals, human H3N2 influenza A virus infections have occurred in dogs and cats in recent years in Japan. 相似文献
10.
Takafumi Fujimoto Suzu Sakao Kouzou Oshima Etsuro Yamaha Katsutoshi Arai 《Aquaculture International》2013,21(4):769-781
Tetraploid fish, which are considered as key resources of diploid gametes for further breeding and ploidy manipulation, can be artificially induced by inhibition of the mitotic cell division with hydrostatic pressure or temperature treatments. Although many attempts have been made to induce artificial tetraploid strains, successful establishment of viable and fertile tetraploid strains are rare. In pond loach, Misgurnus anguillicaudatus, natural tetraploid individuals are distributed in wild populations and diploid gametes from the tetraploid fish have been used for the induction of polyploid individuals, but artificially induced tetraploid strains have not been established yet. In the present study, we optimised starting timing of the heat-shock treatment (41 °C for 2 min) to inhibit a mitotic cell division in fertilised eggs of the normal diploid pond loach between 21 and 51 min after insemination at 20 °C. After the treatment, we observed external appearance of hatching larvae and flow cytometrically determined ploidy status of the resultant larvae. Although tetraploid and diploid/tetraploid mosaic larvae were obtained, the optimum timings for induction of tetraploidy varied amongst crosses. Various kinds of ploidy such as haploidy, diploidy, triploidy, pentaploidy, hexaploidy, aneuploidy and mosaic were detected in non-optimum heat-shock timings for tetraploidisation. Survivors, a tetraploid and a diploid/tetraploid mosaic male, matured at the age of 1-year-old, but they produced functional haploid spermatozoa. 相似文献