Tracking FACT and the RNA polymerase II elongation complex through chromatin in vivo     

Saunders A  Werner J  Andrulis ED  Nakayama T  Hirose S  Reinberg D  Lis JT 《Science (New York, N.Y.)》2003,301(5636):1094-1096

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Role of histone H3 lysine 9 methylation in epigenetic control of heterochromatin assembly     

Nakayama J  Rice JC  Strahl BD  Allis CD  Grewal SI 《Science (New York, N.Y.)》2001,292(5514):110-113

The assembly of higher order chromatin structures has been linked to the covalent modifications of histone tails. We provide in vivo evidence that lysine 9 of histone H3 (H3 Lys9) is preferentially methylated by the Clr4 protein at heterochromatin-associated regions in fission yeast. Both the conserved chromo- and SET domains of Clr4 are required for H3 Lys9 methylation in vivo. Localization of Swi6, a homolog of Drosophila HP1, to heterochomatic regions is dependent on H3 Lys9 methylation. Moreover, an H3-specific deacetylase Clr3 and a beta-propeller domain protein Rik1 are required for H3 Lys9 methylation by Clr4 and Swi6 localization. These data define a conserved pathway wherein sequential histone modifications establish a "histone code" essential for the epigenetic inheritance of heterochromatin assembly.  相似文献   

Introduction of nucleophiles and spectroscopic probes into antibody combining sites   总被引：4，自引：0，他引：4  

S J Pollack  G R Nakayama  P G Schultz 《Science (New York, N.Y.)》1988,242(4881):1038-1040

A general chemical strategy has been developed whereby antibody combining sites can be selectively derivatized with natural or synthetic molecules, such as catalytic groups, drugs, metals, or reporter molecules. Cleavable affinity labels were used to selectively introduce a thiol into the combining site of the immunoglobulin A MOPC 315. This thiol acted both as a nucleophile to accelerate ester thiolysis 60,000-fold and as a handle for selectively derivatizing the antibody with additional functional groups. For example, derivatization of the antibody with a fluorophore made possible a direct spectroscopic assay of antibody-ligand complexation. This chemistry should not only extend our ability to exploit antibody specificity in chemical catalysis, diagnostics, and therapeutics, but may also prove generally applicable to the functional modification of other proteins for which detailed structural information is unavailable.  相似文献   

Analysis of antibody response by temperature-sensitive measles vaccine strain in the cotton rat model     

Haga T  Murayama N  Shimizu Y  Saito A  Sakamoto T  Morita T  Komase K  Nakayama T  Uchida K  Katayama T  Shinohara A  Koshimoto C  Sato H  Miyata H  Katahira K  Goto Y 《Comparative immunology, microbiology and infectious diseases》2009,32(5):395-406

Measles virus (MeV) vaccine strain, AIK-C, is temperature sensitive (ts), which is thought to be associated with attenuation of virus pathogenicity. In this study, replication and antibody response were examined in cotton rats using viruses carrying different forms of the P gene, which is responsible for the ts phenotype of strain AIK-C and its parental Edmonston strain. When cotton rats were inoculated intranasally, ts viruses neither replicated in lungs, nor reproducibly generated an antibody response. When inoculated intramusculary (i.m.), however, ts strains raised an antibody titer in all animals. This response was not observed when ultraviolet-inactivated virus was used. ts virus, inoculated i.m., was recovered from cotton rat drainage lymph nodes. These results suggest that ts virus, inoculated i.m., could replicate in the cotton rat, presumably at the superficial lymph node, and induce an antibody response. Therefore, cotton rats can serve as a small-animal model for investigating immune responses to safer ts vaccine, as well as recombinant vaccine using AIK-C as a vector for protection against other infectious agents.  相似文献   

Trickle irrigation: Predominant bacteria in treated Colorado River water and biologically clogged emitters     

R. G. Gilbert  F. S. Nakayama  D. A. Bucks  O. F. French  K. C. Adamson  R. M. Johnson 《Irrigation Science》1982,3(2):123-132

Summary Bacterial numbers and predominant bacterial types were determined in trickle irrigation systems receiving treated Colorado River water. Fourteen bacterial genera were isolated and identified from 86 water and sediment samples collected from trickle emitter systems receiving six water treatments. The bacteria identified were common aquatic and soil microbes and the genera in order of prevalence were Pseudomonas, Flavobacterium, Vibrio, Brevibacterium, Micrococcus, and Bacillus. A greater diversity of bacterial types was found in water that was sand filtered and received no chemical treatment. Regardless of the water treatment, Pseudomonas stutzeri was the predominant bacterium followed by Flavobacterium lutescens. The data indicated that pigmented bacteria, F. lutescens and ytophaga hutchinsonii caused the yellow color of the slime deposits in biologically clogged emitters; and, their growth was presumably supported by P. stutzeri., a nonpigmented bacterium. The occurrence of Bacillus sp. was enhanced by sand and screen filtration and markedly reduced by chemical conditioning the water with either chlorine and acid or acid alone. No strictly anaerobic bacteria, such as Clostridium sp., were detected in water treated with chlorine and acid. Iron bacteria, Sphaerotilus spp., were not detected in any water or sediment samples from trickle irrigation systems.Contribution from the U.S. Department of Agriculture, Science and Education Administration, Agricultural Research  相似文献   

Intraspecific differentiation and geographical distribution of Wx alleles for low amylose content in endosperm of foxtail millet, Setaria italica (L.) Beauv.     

Hiroki Nakayama  Muhammad Afzal  Kazutoshi Okuno 《Euphytica》1998,102(3):289-293

To clarify the genetic mechanism which controls the variation in amylose content among nonwaxy landraces of foxtail millet, the inheritance of different starch types in endosperm was examined by I₂-KI staining. The level of starch granule bound protein in foxtail millet endosperm was also analyzed using SDS-PAGE. The segregation for starch types in F₂ and F₃ seeds determined by I₂-KI staining showed that there are three different alleles at the waxy (wx) locus. A major protein bound to starch granules was detected in nonwaxy endosperm but it was absent in most of the waxy endosperm, suggesting that the protein is the Wx gene product which is responsible for the synthesis of amylose in endosperm. The level of Wx protein proportionally corresponded to the amylose content among nonwaxy landraces. This implies that two different Wx alleles regulate quantitative levels of Wx protein. Landraces with the allele for low amylose content are from Taiwan, the Philippines, Indonesia and Thailand. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

A tetraploid Echinochloa with plagiotropic tillers: Its distribution and habitat in the northern part of the main island of Japan     

Kentaro Yasuda  Kaoru Mori  Yuichiro Nakayama 《Weed Biology and Management》2020,20(2):82-88

An annual Echinochloa with plagiotropic tillers (semi‐erect type) was found on a paddy levee in Miyagi prefecture in Japan. This semi‐erect type had tetraploid chromosome numbers (2n = 36) and would be expected to be E. oryzicola. However, its appearance was distinct from that of E. oryzicola. To collect seed samples and clarify its distribution and habitat, exploration and collection surveys were carried out in the northern part of Honshu, the main island of Japan in 2014, 2017, and 2018. Thirty‐two populations that were assumed to be the semi‐erect type were found and their mature seeds were collected. Based on the results of chromosome counts and growth form analyses, all of them were confirmed to be the semi‐erect type. The 32 populations were distributed in the prefectures of Aomori, Iwate, Akita, Miyagi, Yamagata, Fukushima, and Niigata, and located in paddy fields, abandoned paddy fields, paddy levees, roadsides, vacant land, and scree slopes. Our surveys indicated that the semi‐erect type grew in wet and dry disturbed habitats at an early stage of secondary succession including paddy fields in the northern part of the main island of Japan.  相似文献   

Antigenic differences of the scuticociliate Miamiensis avidus from Japan     

J-Y Song  K Sasaki  T Okada  M Sakashita  H Kawakami  S Matsuoka  H-S Kang  K Nakayama  S-J Jung  M-J Oh  S-I Kitamura 《Journal of fish diseases》2009,32(12):1027-1034

In Japan and Korea, outbreaks of scuticociliatosis have frequently occurred in Japanese flounder, Paralichthys olivaceus . Morphological observations and small subunit rRNA gene sequences have shown that the causative agent of scuticociliatosis in the flounder is Miamiensis avidus (syn. Philasterides dicentrarchi ). In this study, we elucidated the antigenic differences between six Japanese M. avidus isolates as an initial step toward developing an effective vaccine against the disease. Four Japanese flounder isolates (IyoI, Nakajima, JF05To and Mie0301 isolates), one spotted knifejaw, Oplegnathus punctatus, isolate (SK05Kyo), and one ridged-eye flounder, Pleuronichthys cornutus , isolate (RF05To) were subjected to serological analysis. Antisera against IyoI, SK05Kyo, Nakajima and Mie0301 isolates were raised in rabbits and used for immobilization assays and Western blotting. Immobilization assays showed that the six isolates could be divided into three groups, tentatively designated serotype I for IyoI, JF05To, RF05To, SK05Kyo, serotype II for Nakajima and serotype III for Mie0301. Western blotting results supported these three serotypes, with marked similarities in the banding profiles of IyoI, JF05To, RF05To and SK05Kyo isolates, which were distinct from the Nakajima and Mie0301 isolates. Three isolates, IyoI, Nakajima and Mie0301 that were selected as representatives of each serotype, were highly pathogenic to Japanese flounder by experimental infection. Based on these findings, we propose that there are at least three M. avidus serotypes in Japan.  相似文献   

Novel capsid genes (g23) of T4-type bacteriophages in a Japanese paddy field     

Takeshi Fujii  Natsuko Nakayama  Mizuhiko Nishida  Hiroyuki Sekiya  Naoto Kato  Susumu Asakawa  Makoto Kimura   《Soil biology & biochemistry》2008,40(5):1049-1058

Viruses exist everywhere on the planet. Recent development in viral genomics confirmed that genomic information is preserved among viral subsets and can be used for phylogenetic classification of viruses and for evaluation of viral diversity in the environment. The capsid gene of T4-type bacteriophages, g23, is the most widely applied gene for evaluating the diversity of the T4-type bacteriophage family. In this study, we applied denaturing gradient gel electrophoresis to PCR products of DNA with g23-specific primers that were extracted from a Japanese paddy field under long-term fertilizer trial and obtained 39 different g23 clones at the DNA level. They showed identities of 27–99% with the clones within the NCBI database at the amino acid level. They were quite distinctive from those obtained in marine environments and most of them formed six phylogenetically novel groups in the T4-type bacteriophage family with the clones obtained from another paddy field. The existence of six novel groups was confirmed from molecular analysis of all the amino acid sequences between the primers, of the amino acid sequences excluding hypervariable region, and of those of conserved regions. These findings indicate that T4-type bacteriophage communities in paddy fields consist of previously uncharacterized members phylogenetically distant from those in marine environments. The type of fertilizers and the stage during rice cultivation were not the major factors in determining T4-type bacteriophage communities in the paddy field.  相似文献   

Misidentifications of Echinochloa crus‐galli var. formosensis as Echinochloa oryzicola as a result of similar cpDNA sequences     

Kentaro Yasuda  Yuichiro Nakayama 《Weed Biology and Management》2019,19(3):93-102

Echinochloa crus‐galli (L.) Beauv. var. formosensis Ohwi (2n = 6x = 54, AABBCC genomes) and Echinochloa oryzicola (Vasinger) Vasinger (2n = 4x = 36, AABB) are major paddy weeds in East and Southeast Asia. E. oryzicola has been generally considered to be a paternal genome donor of E. crus‐galli s. l., which includes E. crus‐galli var. formosensis based on cpDNA sequences. Thus, molecular characterization using polymerase chain reaction‐restriction fragment length polymorphism analysis of cpDNA has been proposed as a reliable method for discriminating between the two species. In this study, we report that four accessions of E. crus‐galli var. formosensis from Okinawa, Nagasaki, Shizuoka and Tokyo had similar cpDNA sequences to E. oryzicola and had been misidentified as E. oryzicola using molecular methods. In addition, our results demonstrated that these accessions likely inherited their chloroplast genomes from E. oryzicola and not from an anonymous diploid species during polyploidization. Our findings provide new insights into the evolution of E. crus‐galli s. l. and suggest that identification using the cpDNA molecular method alone is not an appropriate approach to differentiate E. crus‐galli var. formosensis and E. oryzicola.  相似文献