Chromosome analysis of tea plant (Camellia sinensis), an important commercial crop used to prepare beverages throughout the world, was conducted using fluorescence in situ hybridization (FISH) and chromosome image analyzing system IV (CHIAS IV) software. Chromosomes of C. japonica, a popular woody plant used as an ornamental tree and an important breeding resource for tea plants, were used for comparison with C. sinensis. Both C. sinensis and C. japonica comprised 30 chromosomes. The 5S rDNA, a fundamental repeat sequence and a landmark for FISH, was used for Camellia karyotyping. We observed one 5S rDNA locus on two chromosomes in both the species and confirmed the presence of bivalents in the meiotic cells of interspecific hybrids between C. japonica and C. sinensis. These results suggest that the two species have homoeologous chromosomes. C. sinensis chromosomes were analyzed using CHIAS IV, which performs quantitative karyotyping. This is the first report on the karyotyping of the Japanese tea plant C. sinensis by FISH and quantitative image analysis using CHIAS IV. This report will accelerate the use of cytological and genetic linkage map analysis in tea breeding.
{"title":"Chromosome analysis of tea plant (Camellia sinensis) and ornamental camellia (Camellia japonica)","authors":"Kazumi Furukawa, S. Sugiyama, T. Ohta, N. Ohmido","doi":"10.11352/SCR.20.9","DOIUrl":"https://doi.org/10.11352/SCR.20.9","url":null,"abstract":"Chromosome analysis of tea plant (Camellia sinensis), an important commercial crop used to prepare beverages throughout the world, was conducted using fluorescence in situ hybridization (FISH) and chromosome image analyzing system IV (CHIAS IV) software. Chromosomes of C. japonica, a popular woody plant used as an ornamental tree and an important breeding resource for tea plants, were used for comparison with C. sinensis. Both C. sinensis and C. japonica comprised 30 chromosomes. The 5S rDNA, a fundamental repeat sequence and a landmark for FISH, was used for Camellia karyotyping. We observed one 5S rDNA locus on two chromosomes in both the species and confirmed the presence of bivalents in the meiotic cells of interspecific hybrids between C. japonica and C. sinensis. These results suggest that the two species have homoeologous chromosomes. C. sinensis chromosomes were analyzed using CHIAS IV, which performs quantitative karyotyping. This is the first report on the karyotyping of the Japanese tea plant C. sinensis by FISH and quantitative image analysis using CHIAS IV. This report will accelerate the use of cytological and genetic linkage map analysis in tea breeding.","PeriodicalId":10221,"journal":{"name":"Chromosome science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82226500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Buntarika Nuntha, S. Kikuchi, T. Taychasinpitak, H. Sassa, T. Koba
Although Torenia fournieri (2n=2x=18) and Torenia baillonii (2n=2x=16) have different chromosome numbers, almost all of the parental chromosomes form bivalents by interspecific pairing during meiosis in interspecific hybrids. Here, we produced another hybrid between the two species and its six BC1F1 progenies (F1 hybrid × T. baillonii). These plants had previously unreported chromosome compositions: the total chromosome number was 34, as expected for allotetraploids, but some T. fournieri chromosomes were gained and some T. baillonii chromosomes were lost. Plants with these new karyotypes grew well and showed different morphologies. This study indicates that two parental genomes in interspecific hybrids share several interchangeable homoeologous chromosomes.
虽然富氏托伦虫(2n=2x=18)和巴氏托伦虫(2n=2x=16)的染色体数目不同，但在种间杂交减数分裂过程中，几乎所有亲本染色体都通过种间配对形成二价体。在这里，我们在两个物种和它的6个BC1F1后代之间产生了另一个杂交种(F1 hybrid × T. baillonii)。这些植物的染色体组成以前未被报道:染色体总数为34，与异体四倍体的预期一致，但一些T. fournieri染色体得到了，一些T. baillonii染色体丢失了。具有这些新核型的植株生长良好，表现出不同的形态。本研究表明，种间杂交的两个亲本基因组具有几个可互换的同源染色体。
{"title":"New karyotypes of an interspecific hybrid of Torenia fournieri and Torenia baillonii and its progenies","authors":"Buntarika Nuntha, S. Kikuchi, T. Taychasinpitak, H. Sassa, T. Koba","doi":"10.11352/SCR.19.37","DOIUrl":"https://doi.org/10.11352/SCR.19.37","url":null,"abstract":"Although Torenia fournieri (2n=2x=18) and Torenia baillonii (2n=2x=16) have different chromosome numbers, almost all of the parental chromosomes form bivalents by interspecific pairing during meiosis in interspecific hybrids. Here, we produced another hybrid between the two species and its six BC1F1 progenies (F1 hybrid × T. baillonii). These plants had previously unreported chromosome compositions: the total chromosome number was 34, as expected for allotetraploids, but some T. fournieri chromosomes were gained and some T. baillonii chromosomes were lost. Plants with these new karyotypes grew well and showed different morphologies. This study indicates that two parental genomes in interspecific hybrids share several interchangeable homoeologous chromosomes.","PeriodicalId":10221,"journal":{"name":"Chromosome science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80523827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuki Hara, Kenta Adachi, Shunsuke Kagohashi, K. Yamagata, H. Tanabe, S. Kikuchi, S. Okumura, A. Kimura
Across species, eukaryotic chromosomes share common features at the molecular level. However, common features at the cellular level are not well investigated. A correlation has been suggested between the linear packing ratio of mitotic chromosomes and the intra-nuclear DNA density, by comparing these values in the nematode Caenorhabditis elegans. In this study, these values were measured and compared among several metazoan and plant species. The obtained values corroborated the correlation proposed in the previous study, supporting the theory that intra-nuclear DNA density is a common regulator of chromosome condensation. Moreover, the comparison among different species suggested a correlation between the length of a mitotic chromosome and the nuclear volume to the power of 2/3. Given this observation, we speculate that: (i) a rate-limiting component defines the length of a mitotic chromosome that is proportional to the nuclear surface area, and (ii) such regulation of the mitotic chromosomal length may play a role in maintaining the ratio between the cell size and the metaphase plate.
{"title":"Scaling relationship between intra-nuclear DNA density and chromosomal condensation in metazoan and plant","authors":"Yuki Hara, Kenta Adachi, Shunsuke Kagohashi, K. Yamagata, H. Tanabe, S. Kikuchi, S. Okumura, A. Kimura","doi":"10.11352/SCR.19.43","DOIUrl":"https://doi.org/10.11352/SCR.19.43","url":null,"abstract":"Across species, eukaryotic chromosomes share common features at the molecular level. However, common features at the cellular level are not well investigated. A correlation has been suggested between the linear packing ratio of mitotic chromosomes and the intra-nuclear DNA density, by comparing these values in the nematode Caenorhabditis elegans. In this study, these values were measured and compared among several metazoan and plant species. The obtained values corroborated the correlation proposed in the previous study, supporting the theory that intra-nuclear DNA density is a common regulator of chromosome condensation. Moreover, the comparison among different species suggested a correlation between the length of a mitotic chromosome and the nuclear volume to the power of 2/3. Given this observation, we speculate that: (i) a rate-limiting component defines the length of a mitotic chromosome that is proportional to the nuclear surface area, and (ii) such regulation of the mitotic chromosomal length may play a role in maintaining the ratio between the cell size and the metaphase plate.","PeriodicalId":10221,"journal":{"name":"Chromosome science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78068634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The silkworm, Bombyx mori, is a lepidopteran model with long history of the domesticated insect for silk production, which contributed to human life as well as insect sciences. In chromosome science, the silkworm could be the first record of karyotype count in Lepidoptera. Because of the holokinetic chromosomes, precise chromosome identification and karyotype had been difficult until BAC-FISH (fluorescence in situ hybridization with bacterial chromosome (BAC) DNAs as probes) was applied for the silkworm chromosome analysis. Here we review the research histories for the first B. mori karyotype and its contribution for chromosome science and comparative genomics in Lepidoptera.
{"title":"A history of chromosome identification in Bombyx mori","authors":"K. Sahara, A. Yoshido, Y. Yasukochi","doi":"10.11352/SCR.19.3","DOIUrl":"https://doi.org/10.11352/SCR.19.3","url":null,"abstract":"The silkworm, Bombyx mori, is a lepidopteran model with long history of the domesticated insect for silk production, which contributed to human life as well as insect sciences. In chromosome science, the silkworm could be the first record of karyotype count in Lepidoptera. Because of the holokinetic chromosomes, precise chromosome identification and karyotype had been difficult until BAC-FISH (fluorescence in situ hybridization with bacterial chromosome (BAC) DNAs as probes) was applied for the silkworm chromosome analysis. Here we review the research histories for the first B. mori karyotype and its contribution for chromosome science and comparative genomics in Lepidoptera.","PeriodicalId":10221,"journal":{"name":"Chromosome science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90647305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Following its recent rapid development, nanotechnology is now an effective tool in chromosome science and technology (Fukui and Ushiki 2007). It can be used effectively for both functional and structural studies of chromosomes, although its direct advantages have been shown mainly in structural studies. Thus, it is expected that nanotechnology will be extensively used in the field of chromosome structure. This review describes three of the most promising and effective nanotechnologies and related technology: super-resolution microscopy (in particular, three-dimensional structured illumination microscopy, 3D-SIM), focused ion beam/scanning electron microscopy (FIB/SEM), and scanning transmission electron microscopy (STEM). Their applications in the elucidation of higher-order chromosome structure are presented and discussed based on the achievements already attained.
{"title":"Contribution of nanotechnology to chromosome science","authors":"K. Fukui","doi":"10.11352/SCR.19.51","DOIUrl":"https://doi.org/10.11352/SCR.19.51","url":null,"abstract":"Following its recent rapid development, nanotechnology is now an effective tool in chromosome science and technology (Fukui and Ushiki 2007). It can be used effectively for both functional and structural studies of chromosomes, although its direct advantages have been shown mainly in structural studies. Thus, it is expected that nanotechnology will be extensively used in the field of chromosome structure. This review describes three of the most promising and effective nanotechnologies and related technology: super-resolution microscopy (in particular, three-dimensional structured illumination microscopy, 3D-SIM), focused ion beam/scanning electron microscopy (FIB/SEM), and scanning transmission electron microscopy (STEM). Their applications in the elucidation of higher-order chromosome structure are presented and discussed based on the achievements already attained.","PeriodicalId":10221,"journal":{"name":"Chromosome science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90935773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chromosome elimination and chromatin diminution occur in various species including single-cell ciliates and several multicellular animals. DNA methylcytosine (5mC) and histone modifications have been identified as markers of the eliminated DNA and chromatins in ciliate and finch. Here we examined the levels of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC; an intermediate of active DNA demethylation) in the male testicular cells of the inshore hagfish Eptatretus burgeri and simultaneously detected germline-restricted repetitive sequences (EEEb1) to identify the chromosomes restricted to germ cells (E-chromosomes). We detected 5mC and 5hmC signals at all chromosomes in the spermatogonia and in all of the interphase nuclei whereas 5mC signals were selectively located on the chromosomes without EEEb1 signals in the spermatocytes’ metaphase, suggesting no 5mC signal on the E-chromosomes. No significant difference in 5hmC levels between the E-chromosomes and the other chromosomes, was detected in the spermatocytes. This chromosome-specific hypomethylation has never been detected in mouse or zebrafish germ cells. These results therefore suggest that the DNA methylation pattern of the E-chromosomes, namely those presumptively eliminated in somatic differentiation, are altered just before or during meiosis. This exclusive alteration of the methylation pattern may play a key role in the chromosome elimination in hagfish species’ embryogenesis.
{"title":"Preferential demethylation of DNA cytosine on the chromosomes restricted to germ cells in the spermatocytes but not the spermatogonia in the inshore hagfish, Eptatretus burgeri","authors":"Y. Goto, Daiki Osawa, Souichirou Kubota","doi":"10.11352/SCR.19.11","DOIUrl":"https://doi.org/10.11352/SCR.19.11","url":null,"abstract":"Chromosome elimination and chromatin diminution occur in various species including single-cell ciliates and several multicellular animals. DNA methylcytosine (5mC) and histone modifications have been identified as markers of the eliminated DNA and chromatins in ciliate and finch. Here we examined the levels of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC; an intermediate of active DNA demethylation) in the male testicular cells of the inshore hagfish Eptatretus burgeri and simultaneously detected germline-restricted repetitive sequences (EEEb1) to identify the chromosomes restricted to germ cells (E-chromosomes). We detected 5mC and 5hmC signals at all chromosomes in the spermatogonia and in all of the interphase nuclei whereas 5mC signals were selectively located on the chromosomes without EEEb1 signals in the spermatocytes’ metaphase, suggesting no 5mC signal on the E-chromosomes. No significant difference in 5hmC levels between the E-chromosomes and the other chromosomes, was detected in the spermatocytes. This chromosome-specific hypomethylation has never been detected in mouse or zebrafish germ cells. These results therefore suggest that the DNA methylation pattern of the E-chromosomes, namely those presumptively eliminated in somatic differentiation, are altered just before or during meiosis. This exclusive alteration of the methylation pattern may play a key role in the chromosome elimination in hagfish species’ embryogenesis.","PeriodicalId":10221,"journal":{"name":"Chromosome science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81752961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. CHEMICALS (1) Colchicine stock solution (1mg/ml, 0.1% solution) (a) 50 mg colchicine (b) 50 ml distilled water (D.W.) * Store in a brown bottle and keep in a refrigerator. (2) Hypotonic solution (1% Sodium citrate solution) (a) 1 g Trisodium citrate dihydrate (b) 100 ml D.W. (3) Colchicine-hypotonic solution (* freshly prepared) 10 ml Hypotonic solution with 0.005 % colchicine (a) 0.5 ml Colchicine stock solution (b) 9.5 ml Hypotonic solution (4) Fixative I (* freshly prepared) 60% 1:1 Acetic-ethanol (a) Glacial acetic acid 3 ml (b) Ethanol (>99.5%) 3 ml (c) D.W. 4 ml * Don’t store Fixative I overnight, because it turns rapidly into ethyl acetate, which is deleterious to mitotic cells. * Don’t use old glacial acetic acid and ethanol that are near the bottom of a stock bottle or that have been left for several months. Both chemicals tend to absorb moisture from the air and chromosomes will be damaged by the contamination of water. (5) Fixative II (* freshly prepared) 4 ml Absolute 1:1 Acetic-ethanol (a) Glacial acetic acid 2 ml (b) Ethanol (>99.5%) 2 ml (6) Fixative III 2ml Glacial acetic acid (GAA) II. APPARATUS (Fig. 1) (1) A transmitted stereomicroscope (x20-x40) for dissecting out organs (Fig. 1a). (2) A pair of dissecting needles (Fig. 1b). (3) Four Pasteur pipettes each with a rubber nipple (Fig. 1c). (4) Centrifugation tube (Spits tube) (Fig. 1d). (5) Depression slides (hole slides) (Fig. 1e). (6) Slide glasses (Fig. 1f). * Store slides in 80% ethanol and dry with washed clean gauze as necessary. * If slides are oily, add a drop of fixative I on the slide, and clear with paper or washed clean gauze. (7) Test tube stand (Fig. 1g). (8) Filter paper (blotting paper) (Fig. 1h). (9) Rolled filter paper or paper towel (Fig. 1i). (10) Fingerstalls for the thumb and the forefinger (Fig. 1j). * To protect fingers from fixative. * Cut the tip of fingers of a vinyl glove for right hand. (11) Washed cotton gauze or tissue paper (Fig. 1k). (12) A glass engraving pen for label (Fig. 1l). (13) Forceps to open cocoons (Fig. 1m).
{"title":"A manual for ant chromosome preparations (an improved air-drying method) and Giemsa staining","authors":"H. Imai","doi":"10.11352/SCR.19.57","DOIUrl":"https://doi.org/10.11352/SCR.19.57","url":null,"abstract":"I. CHEMICALS (1) Colchicine stock solution (1mg/ml, 0.1% solution) (a) 50 mg colchicine (b) 50 ml distilled water (D.W.) * Store in a brown bottle and keep in a refrigerator. (2) Hypotonic solution (1% Sodium citrate solution) (a) 1 g Trisodium citrate dihydrate (b) 100 ml D.W. (3) Colchicine-hypotonic solution (* freshly prepared) 10 ml Hypotonic solution with 0.005 % colchicine (a) 0.5 ml Colchicine stock solution (b) 9.5 ml Hypotonic solution (4) Fixative I (* freshly prepared) 60% 1:1 Acetic-ethanol (a) Glacial acetic acid 3 ml (b) Ethanol (>99.5%) 3 ml (c) D.W. 4 ml * Don’t store Fixative I overnight, because it turns rapidly into ethyl acetate, which is deleterious to mitotic cells. * Don’t use old glacial acetic acid and ethanol that are near the bottom of a stock bottle or that have been left for several months. Both chemicals tend to absorb moisture from the air and chromosomes will be damaged by the contamination of water. (5) Fixative II (* freshly prepared) 4 ml Absolute 1:1 Acetic-ethanol (a) Glacial acetic acid 2 ml (b) Ethanol (>99.5%) 2 ml (6) Fixative III 2ml Glacial acetic acid (GAA) II. APPARATUS (Fig. 1) (1) A transmitted stereomicroscope (x20-x40) for dissecting out organs (Fig. 1a). (2) A pair of dissecting needles (Fig. 1b). (3) Four Pasteur pipettes each with a rubber nipple (Fig. 1c). (4) Centrifugation tube (Spits tube) (Fig. 1d). (5) Depression slides (hole slides) (Fig. 1e). (6) Slide glasses (Fig. 1f). * Store slides in 80% ethanol and dry with washed clean gauze as necessary. * If slides are oily, add a drop of fixative I on the slide, and clear with paper or washed clean gauze. (7) Test tube stand (Fig. 1g). (8) Filter paper (blotting paper) (Fig. 1h). (9) Rolled filter paper or paper towel (Fig. 1i). (10) Fingerstalls for the thumb and the forefinger (Fig. 1j). * To protect fingers from fixative. * Cut the tip of fingers of a vinyl glove for right hand. (11) Washed cotton gauze or tissue paper (Fig. 1k). (12) A glass engraving pen for label (Fig. 1l). (13) Forceps to open cocoons (Fig. 1m).","PeriodicalId":10221,"journal":{"name":"Chromosome science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76397801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The locations of the 18S-5.8S-25S and 5S ribosomal RNA genes (rDNAs) on the chromosomes in the seedlings obtained from open-pollination of apple ‘Sensyu’ (Malus × domestica Borkh.) were determined using fluorescence in situ hybridization (FISH). 18S-5.8S-25S and 5S rDNA probes were labeled with biotin and hybridization signals were detected using a fluorescein isothiocyanate (FITC)-avidin conjugate on the chromosomes counterstained with DAPI. The 18S-5.8S-25S rDNA signals were detected in the telomeric positions of eight chromosomes among 34. These sites were located on two long, two relatively long, two medium, and two relatively short chromosomes. The two 5S rDNA sites were located at centromeric positions of relatively short chromosomes which do not possess 18S-5.8S-25S rDNA sites. The numbers and positions of rDNA sites were stable among the seedlings.
{"title":"Detection of ribosomal RNA genes in apple (Malus × domestica) using fluorescence in situ hybridization","authors":"Masashi Yamamoto, S. Moriya, Toshiya Yamamoto","doi":"10.11352/SCR.19.33","DOIUrl":"https://doi.org/10.11352/SCR.19.33","url":null,"abstract":"The locations of the 18S-5.8S-25S and 5S ribosomal RNA genes (rDNAs) on the chromosomes in the seedlings obtained from open-pollination of apple ‘Sensyu’ (Malus × domestica Borkh.) were determined using fluorescence in situ hybridization (FISH). 18S-5.8S-25S and 5S rDNA probes were labeled with biotin and hybridization signals were detected using a fluorescein isothiocyanate (FITC)-avidin conjugate on the chromosomes counterstained with DAPI. The 18S-5.8S-25S rDNA signals were detected in the telomeric positions of eight chromosomes among 34. These sites were located on two long, two relatively long, two medium, and two relatively short chromosomes. The two 5S rDNA sites were located at centromeric positions of relatively short chromosomes which do not possess 18S-5.8S-25S rDNA sites. The numbers and positions of rDNA sites were stable among the seedlings.","PeriodicalId":10221,"journal":{"name":"Chromosome science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76404613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The effect of magnesium ions on chromosome structure as observed by scanning electron microscopy (SEM) and scanning transmission electron microscope (STEM) tomography","authors":"A. Dwiranti, H. Takata, S. Uchiyama, K. Fukui","doi":"10.11352/SCR.19.19","DOIUrl":"https://doi.org/10.11352/SCR.19.19","url":null,"abstract":"","PeriodicalId":10221,"journal":{"name":"Chromosome science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86325033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soma Sasakura, Akiyo Yoshida, T. Wako, Kohei Kaneyoshi, Rawin Poonperm, Shinichi Ogawa, Jun Kato, Y. Otsuka, H. Takata, S. Uchiyama, K. Fukui
Despite the efforts of numerous researchers over the years, inner structure of a chromosome is still controversial, although several models have been proposed to date. It is now well known that there are two important structural components to the chromosome, the chromosome scaffold and chromatin fibers. The chromosome scaffold, which is mainly composed of four different proteins, is a protein axis extending longitudinally in both chromatids. The chromatin fiber, which is composed of a DNA strand with histone proteins, is also packed in each chromatid. We used focused ion beam/scanning electron microscope (FIB/SEM) to elucidate these two structural components using human chromosomes. FIB/SEM effectively cuts the human chromosomes by its focused Ga ion beam and the cross-sections were visualized by the resolution of scanning electron microscope. As a result, the chromosome scaffold has been confirmed to be located in the central region of each chromatid. The distribution of chromatin fiber in the chromosome’s inner space was also detected. It seems to be distributed more or less randomly within a chromosome. These results strongly indicated that the nanotechnology afforded by FIB/SEM is an effective method to reveal the chromosome’s inner structure in detail.
{"title":"Structural analysis of human chromosome by FIB/SEM","authors":"Soma Sasakura, Akiyo Yoshida, T. Wako, Kohei Kaneyoshi, Rawin Poonperm, Shinichi Ogawa, Jun Kato, Y. Otsuka, H. Takata, S. Uchiyama, K. Fukui","doi":"10.11352/SCR.19.25","DOIUrl":"https://doi.org/10.11352/SCR.19.25","url":null,"abstract":"Despite the efforts of numerous researchers over the years, inner structure of a chromosome is still controversial, although several models have been proposed to date. It is now well known that there are two important structural components to the chromosome, the chromosome scaffold and chromatin fibers. The chromosome scaffold, which is mainly composed of four different proteins, is a protein axis extending longitudinally in both chromatids. The chromatin fiber, which is composed of a DNA strand with histone proteins, is also packed in each chromatid. We used focused ion beam/scanning electron microscope (FIB/SEM) to elucidate these two structural components using human chromosomes. FIB/SEM effectively cuts the human chromosomes by its focused Ga ion beam and the cross-sections were visualized by the resolution of scanning electron microscope. As a result, the chromosome scaffold has been confirmed to be located in the central region of each chromatid. The distribution of chromatin fiber in the chromosome’s inner space was also detected. It seems to be distributed more or less randomly within a chromosome. These results strongly indicated that the nanotechnology afforded by FIB/SEM is an effective method to reveal the chromosome’s inner structure in detail.","PeriodicalId":10221,"journal":{"name":"Chromosome science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74193983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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