Auxins increase the occurrence of leaf-colour variants in Caladium regenerated from leaf explants     

E. U. Ahmed  T. Hayashi  S. Yazawa 《Scientia Horticulturae》2004,100(1-4):153-159

Leaf explants of Caladium ‘Pink Cloud’ were cultured in vitro on MS medium containing various auxins (NAA, IBA, IAA, 2,4,5-T and 2,4-D) in combination with cytokinin (BA). NAA gave the most vigorous in vitro propagation of this plant, and only 15% of the plants were leaf-colour variants on the medium containing 0.5 μmol NAA. Leaf colour variation was observed in all plants regenerated on the medium containing 2,4-D at 0.5–4.5 μmol. In hormone-free medium, only a few leaf-colour variants (6%) occurred, but the rate of plant regeneration was very low. Application of 0.5 μmol NAA together with 4.5 μmol BA seemed to be the most appropriate for in vitro propagation of Caladium ‘Pink Cloud’ with only a few leaf-colour variants.  相似文献   

Phylogenetic relationships of rodent pinworms (genus Syphacia) in Japan inferred from mitochondrial CO1 gene sequences     

Okamoto M  Urushima H  Iwasa M  Hasegawa H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(5):545-547

Species of the genus Syphacia are considered to have generally co-evolved with their rodent hosts. This study determined partial sequences of the CO1 gene from several species in the genus Syphacia and discuss the relationships between pinworms and their hosts. Syphacia montana, which parasitizes Microtinae, was closely related to S. frederici and S. obvelata, which parasitize Murinae. Although both S. obvelata and S. ohtaorum parasitize rodents in the genus Mus, these two species were not found to be closely related to each other. Syphacia frederici, S. emileromani and S. agraria are all pinworms of the Apodemus species, but genetic affiliation between these three species was not indicated. These facts suggest that the co-evolutionary relationship between species of the genus Syphacia and their host rodents may not so strict and host switching has probably occurred during the course of evolution.  相似文献   

Telomere length and telomerase activity in canine mammary gland tumors     

Yazawa M  Okuda M  Setoguchi A  Iwabuchi S  Nishimura R  Sasaki N  Masuda K  Ohno K  Tsujimoto H 《American journal of veterinary research》2001,62(10):1539-1543

OBJECTIVE: To measure telomere length and telomerase activity in naturally occurring canine mammary gland tumors. SAMPLE POPULATION: 27 mammary gland tumor specimens obtained during resection or necropsy and 12 mammary gland tissue specimens obtained from healthy (control) dogs. PROCEDURE: Telomere length in tissue specimens was measured by use of restriction endonuclease digestion and Southern blot analysis. Telomerase activity was measured by use of a telomeric repeat amplification protocol assay. RESULTS: Telomere length in mammary gland tumors ranged from 11.0 to 21.6 kilobase pairs (kbp; mean +/- SEM, 14.5+/-0.5 kbp) but did not differ among tumor types. Telomeres in mammary gland tumors were slightly shorter than in normal tissue specimens, but telomere length could not be directly compared between groups, because mean age of dogs was significantly different between groups. Age was negatively correlated with telomere length in control dogs but was not significantly correlated with length in affected dogs. Telomerase activity was detected in 26 of 27 mammary gland tumors and in 4 of 12 normal tissue specimens. However, telomerase activity and telomere length were not correlated in tumor specimens. CONCLUSIONS AND CLINICAL RELEVANCE: Telomere length is maintained in canine mammary gland tumors regardless of the age of the affected dog. Measurement of telomere length may be a useful tool for monitoring the in vivo effects of telomerase inhibitors in dogs with tumors.  相似文献   

PCR detection of Porcine circovirus type 2 DNA in whole blood,serum, oropharyngeal swab,nasal swab,and feces from experimentally infected pigs and field cases     

Shibata I  Okuda Y  Yazawa S  Ono M  Sasaki T  Itagaki M  Nakajima N  Okabe Y  Hidejima I 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(3):405-408

Porcine circovirus type 2 (PCV2) shedding patterns were investigated by polymerase chain reaction (PCR) for the detection of PCV2 DNA, and the diagnostic suitability of a sample for the PCR was examined by using different types of samples. In the experimental infection, sixteen pigs were inoculated intranasally with PCV2. The samples, including oropharyngeal and nasal swabs, feces, whole blood and serum became positive for PCV2 DNA by PCR immediately after the inoculation, and almost all samples remained positive during the observation period, post-inoculation-day 70. Field samples were collected from 313 pigs in five different age groups. The overall percentages of positive samples in the whole blood, nasal swabs, and feces detected by PCR were 30.4%, 19.2%, and 20.4%, respectively. The frequency of positive samples increased after the nursery stages and reached a peak in the 3 to 4-month-old pigs. These results indicate that PCV2 infection may occur after weaning, that PCV2 DNA may be present in whole blood for a long period after infection, and that whole blood and serum are the most suitable sample types for the PCR analysis of PCV2.  相似文献   

Molecular cloning of the feline telomerase reverse transcriptase (TERT) gene and its expression in cell lines and normal tissues     

Yazawa M  Okuda M  Uyama R  Nakagawa T  Kanaya N  Nishimura R  Sasaki N  Masuda K  Ohno K  Tsujimoto H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(5):573-577

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Natural infection of Chrysanthemum stunt viroid in dahlia plants     

Akiko Nakashima  Munetaka Hosokawa  Shigeichi Maeda  Susumu Yazawa 《Journal of General Plant Pathology》2007,73(3):225-227

For the first time, Chrysanthemum stunt viroid (CSVd) was detected in commercial dahlia bulbs in Japan. CSVd was found in 77.2% of the tested plants (Dahlia spp.). In nucleotide sequence analysis, a CSVd variant was detected consisting of 354 nucleotides, which differed slightly from previously reported CSVd variants. The nucleotide sequence data reported is available in the DDBJ/EMBL/GenBank databases under accession number AB255879.  相似文献   

Ophiostomatoid fungi associated with bark beetles onAbies veitchii in wave-regenerated forests     

Nobuaki Ohtaka  Hayato Masuya  Shigeru Kaneko  Yuichi Yamaoka  Masashi Ohsawa 《Journal of Forest Research》2002,7(3):145-151

Relationships between tree mortality and bark beetle infestation onAbies veitchii at the wave-regenerated forest in Mt. Asahi, Okuchichibu area were investigated. Most of the firs with green needles and newly developed current year’s shoots in the dieback zone were heavily infested by bark beetles before the death of the trees. After heavy infestation of beetles, about half of the infested firs died within the year, and the other half died in the next year. When the species composition of bark beetles and associated ophiostomatoid fungi were investigated in Mt. Asahi and also at a typical wave-regenerated forest in Mt. Shimagare, Yatsugatake area,Cryphalus montanus andC. piceae were dominant beetle species for Mt. Asahi and Mt. Shimagare, respectively.Ophiostoma subalpinum andO. europhioides were dominant fungal species at both wave-generated forests. BecauseO. subalpinum was detected more frequently from deeper areas of sapwood thanO. europhioides, it was suggested that the fungal species may accelerate the death of stressed firs in wave-regenerated forests. Contribution No. 169, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba.  相似文献   

Genomic Reassortants of Pandemic A (H1N1) 2009 Virus and Endemic Porcine H1 and H3 Viruses in Swine in Japan     

Rikio KIRISAWA  Yoshitaka OGASAWARA  Hayato YOSHITAKE  Asuka KODA  Tokujiro FURUYA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(11):1457-1470

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Ionomic Profiling of Rice Genotypes and Identification of Varieties with Elemental Covariation Effects     

Zhang Chengming  Nobuhiro Tanaka  Maria Stefanie Dwiyanti  Matthew Shenton  Hayato Maruyama  Takuro Shinano  Chu Qingnan  Xie Jun  Toshihiro Watanabe 《水稻科学》2022,29(1):76-88

Ionomic profiles are primarily influenced by genetic and environmental factors. Identifying ionomic responses to varietal effects is necessary to understand the ionomic variations among species or subspecies and to potentially understand genetic effects on ionomic profiles. We cultivated 120 rice (Oryza sativa) varieties to seedling stage in identical hydroponic conditions and determined the concentrations of 26 elements (including 3 anions) in the shoots and roots of rice. Although the subspecies effects were limited by the genus Oryza pre-framework and its elemental chemical properties, we found significant differences in ionomic variations in most elements among the aus, indica and japonica subspecies. Principal component analysis of the correlations indicated that variations in the root-to-shoot ionomic transport mechanisms were the main causes of ionomic differences among the subspecies. Furthermore, the correlations were primarily associated with the screening of varieties for elemental covariation effects that can facilitate breeding biofortified rice varieties with safe concentrations of otherwise toxic elements. The japonica subspecies exhibited the strongest elemental correlations and elemental covariation effects, therefore, they showed greater advantages for biofortification than the indica and aus subspecies, whereas indica and aus subspecies were likely safer in metal(loid) polluted soils. We also found that geographical and historical distribution significantly defined the ionomic profiles. Overall, the results of this study provided a reference for further association studies to improve the nutritional status and minimize toxicity risks in rice production.  相似文献   

Results of hyperamplification of centrosomes in naturally developing tumors of dogs.     

A Setoguchi  M Okuda  E Nishida  M Yazawa  T Ishizaka  S H Hong  M Hisasue  R Nishimura  N Sasaki  Y Yoshikawa  K Masuda  K Ohno  H Tsujimoto 《American journal of veterinary research》2001,62(7):1134-1141

OBJECTIVE: To evaluate results of centrosome hyperamplification in naturally developing tumors of dogs. SAMPLE POPULATION: Tumor specimens from 9 dogs with tumors (rhabdomyosarcoma, osteosarcoma, chondrosarcoma, myxosarcoma, and mammary gland tumor) and 2 canine osteosarcoma cell lines. PROCEDURE: 3 antibodies for centrosome proteins (ie, anti-gamma-tubulin, anti-BRCA1, and anti-pericentrin) were used for immunohistochemical analysis. Double immunostaining for centrosomes was used to confirm the specificity of these antibodies for centrosomes. Mutational analysis of the canine p53 gene was carried out by polymerase chain reaction-single-strand conformation polymorphism analysis, and expression of canine MDM2 protein was evaluated by use of immunohistochemical analysis, using anti-MDM2 antibody. RESULTS: Immunohistochemical analysis of dog osteosarcoma cell lines with apparent aneuploidy revealed frequent hyperamplification of centrosomes in the osteosarcoma cell lines. Similar hyperamplified centrosomes were detected in the tumor tissues from all of the 9 tumors. The frequency of cells with hyperamplified centrosomes (3 to 20/cell) in each tumor tissue ranged from 9.50 to 48.1%, whereas centrosome hyperamplification was not observed in normal lymph nodes from these dogs. In 8 of the 9 tumors, mutation of p53 gene or overexpression of MDM2, or both, was detected. CONCLUSIONS AND CLINICAL RELEVANCE: Various types of naturally developing tumors in dogs often have hyperamplification of centrosomes associated with chromosome instability. Hyperamplification of centrosomes is a novel tumor marker for use in cytologic and histologic examinations of clinical specimens obtained from dogs.  相似文献