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1.
Masaki Fujisawa Shigeki Nakayama Tomohisa Nishio Mariko Fujishita Kiwako Hayashi Kimitsune Ishizaki Masataka Kajikawa Katsuyuki T. Yamato Hideya Fukuzawa Kanji Ohyama 《Chromosome research》2003,11(7):695-703
In the haploid dioecious liverwort, Marchantia polymorpha, the X chromosome, but not the Y, carries a cluster of ribosomal RNA genes (rDNAs). Here we show that sequences of 5S, 17S,
5.8S and 26S rDNAs are highly conserved (>99% identity) between the X chromosomal and autosomal rDNA repeat units, but the
intergenic spacer sequences differ considerably. The most prominent difference is the presence of a 615-bp DNA fragment in
the intergenic spacer, X615, which has accumulated predominantly in the rDNA cluster of the X chromosome. These observations
suggest that the rDNA repeat unit on the X chromosome evolved independently of that on autosomes, incorporating sex chromosome-specific
sequences.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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I. Y. Iourov T. Liehr S. G. Vorsanova A. D. Kolotii Y. B. Yurov 《Chromosome research》2006,14(3):223-229
Molecular cytogenetics offers the unique possibility of investigating numerical and structural chromosomal aberrations in
interphase nuclei of somatic cells. Previous fluorescence in-situ hybridization (FISH) investigations gave hints of numerical chromosomal imbalances in the human brain, present as low-level
mosaicism. However, as precise identification of aneuploidy rates in somatic tissues faces major difficulties due to the limitations
of FISH using whole chromosome painting or centromeric probes, in this study low-level mosaicism in the human brain was addressed
for the first time using microdissection-based multicolour banding (MCB) probe sets. We demonstrated that MCB is suitable
for this application and leads to more reliable results than the use of centromeric probes in parallel on the same samples.
Autosomes and the active X chromosome appear as discrete metaphase chromosome-like structures, while the inactive X chromosome
is condensed in more than 95% of interphase nuclei. The frequency of stochastic aneuploidy was found to be 0.2–0.5% (mean
0.35%) per autosome pair, 2% for the X chromosome in the female brain, and 0.4% in the male brain, giving a cumulative frequency
of aneuploidy of approximately 10% in the adult brain. Moreover, MCB as well as multi-probe FISH using centromeric probes
revealed associated signals in a large proportion of brain cells (10–40%). While co-localized signals could not be discriminated
from numerical chromosome imbalances after FISH using centromeric probes, interphase MCB allows such differentiation. In summary,
MCB is the only approach available at present that provides the possibility of characterizing the chromosomal integrity of
arbitrary interphase cell populations. Thus, cytogenetics is no longer limited in its application to dividing cells, which
is a great step forward for brain research. 相似文献
6.
P. Hamon S. Siljak-Yakovlev S. Srisuwan O. Robin V. Poncet S. Hamon A. de Kochko 《Chromosome research》2009,17(3):291-304
The chromosome organization among 15 wild diploid Coffea species and cultivated tetraploid C. arabica was determined by fluorochrome banding (CMA, DAPI) and double fluorescence in-situ hybridization (FISH) of 5S and 18S rDNA
achieved on the same chromosome plates. Two to five chromosome pairs (plus one putative chromosome B) are marked. Overall,
there are two SAT-chromosome pairs for East African species and one for the Malagasy and the West and Central African species.
18S rDNA loci are telomeric and strongly marked the SAT-chromosome pairs. Generally, only one pericentromeric 5S rDNA locus
characterized East African species, while an additional minor locus co-localized with the 18S rDNA-SAT locus for the Malagasy
species and West and Central African species. A combination of rDNA FISH plus CMA and DAPI banding patterns enables identification
of almost all the species, even those for which the genetic or botanical status is still being discussed. C. arabica clearly appears to be an allotetraploid species, including one genome from East Africa and one from West and Central Africa.
However, since the minor 5S rDNA-SAT locus present in West/Central African genomes is not detected, two evolutionary hypotheses
could be put forward for C. arabica. Considering only the diploid species, global trends are obvious in rDNA signal patterns, genome size variations, and geographic
distribution of the species, but there are no clear evolutionary trends. However, complex interactions between these factors
and environmental growing conditions exist, which have resulted in loss and gain of rDNA loci and probably also in copy repeat
number variations in each rDNA family. 相似文献
7.
Marta Gromicho Jean-Pierre Coutanceau Catherine Ozouf-Costaz Maria João Collares-Pereira 《Chromosome research》2006,14(3):297-306
The diploid–polyploid Squalius alburnoides complex resulted from interspecific hybridization. The chromosomal mapping of 28S and 5S ribosomal genes and of (TTAGGG)n telomeric repeats was performed on specimens from the complex and from the sympatric bisexual species S. pyrenaicus (the complex maternal ancestor) as part of an investigation of the evolutionary relationships between genomic constitutions
and the consequences of the ongoing polyploidization process in terms of chromosome reshaping. Contrasting results were obtained.
While results with 5S rDNA and telomeric probes gave an impression of genomic stability, the variability detected with 28S
rDNA probe suggested quite the opposite. The 5S rDNA probe mapped constantly to three chromosomes per haploid genome with
apparently conserved locations in morphologically similar chromosomes; conversely, prominent intra- and inter-individual variations
of 28S rDNA and of syntenic sites with 5S rDNA were detected with regard to number, size and location. Hypotheses for the
causes of such polymorphisms are discussed. The terminal position of most 28S rDNA sites and the absence of detectable interstitial
telomeric sequences suggest a mechanism that does not involve major chromosomal rearrangements. These fishes share similar
patterns for the studied cytogenetic markers which may be taken as evidence of an apparent stability that may be hiding extensive
and subtle genome variations that are possibly related to an ongoing evolutionary process of genome tetraploidization and
speciation. 相似文献
8.
Jiří Široký Martin A. Lysák Jaroslav Doležel Eduard Kejnovský Boris Vyskot 《Chromosome research》2001,9(5):387-393
Genus Silene L. (Caryophyllaceae) contains about 700 species divided into 44 sections. According to recent taxonomic classification this genus also includes taxa previously classified in genera Lychnis and Melandrium. In this work, four Silene species belonging to different sections were studied: S. latifolia (syn. Melandrium album, Section Elisanthe), S. vulgaris (Inflatae), S. pendula (Erectorefractae), and S. chalcedonica (syn. Lychnis chalcedonica, Lychnidiformes). Flow cytometric analysis revealed a genome size of 2.25 and 2.35 pg/2C for S. vulgaris and S. pendula and of 5.73 and 6.59 pg/2C for S. latifolia and S. chalcedonica. All four species have the same chromosome number including the pair of sex chromosomes of the dioecious S. latifolia (2n = 2x = 24). Double target fluorescence in-situ hybridization revealed the chromosomal locations of 25S rDNA and 5S rDNA. A marked variation in number and localization of rDNA loci but no correlation between the numbers of rDNA clusters and genome size was found. FISH and genome size data indicate that nuclear genomes of Silene species are highly diversified as a result of numerous DNA amplifications and translocations. 相似文献
9.
Bruce?S.?Milne Tess?Hoather Patricia?C.M.?O’Brien Fengtang?Yang Malcolm?A.?Ferguson-Smith Jane?Dobson David?Sargan
Many canine tumour types represent useful models for tumours also found in humans. Studies of chromosomal abnormalities in
canine tumours have been impeded by the complexity of the canine karyotype (2n = 78), which has made accurate identification
of rearranged chromosomes difficult and laborious. To overcome this difficulty we have developed a seven-colour paint system
for canine chromosomes, with six sets of chromosome paints covering all chromosomes except Y. Several pairs of canine autosomes
co-locate in the flow karyotype. To distinguish these autosomes from each other, paint sets were supplemented with chromosomes
of red fox and Japanese raccoon dog. Paints were used in fluorescence in-situ hybridization to analyse karyotypes in fourteen canine soft tissue sarcomas. Rearranged karyotypes were observed in seven
tumours, but there was evidence for loss of rearrangement during tissue culture. Five tumours had rearrangements involving
four chromosomes or fewer; one, a chondrosarcoma, had lost seven chromosomes whilst the last, a spindle cell sarcoma, had
rearrangements involving eighteen chromosome pairs. The paint sets described here facilitate the complete cytogenetic analysis
of balanced translocations and other inter-chromosomal rearrangements in canine tumours. We believe that this is the first
canine tumour series to be subjected to this level of analysis. 相似文献
10.
C. G. Ziegler D. K. Lamatsch C. Steinlein W. Engel M. Schartl M. Schmid 《Chromosome research》2003,11(1):23-35
The cyprinid fish Alburnus alburnus possesses one of the largest supernumerary chromosomes in all vertebrates. In the present study, amplified fragment length polymorphism analyses (AFLP) and fluorescence in-situ hybridization (FISH) were performed in order to characterize these extraordinary chromosomes in detail. Sequence analysis of the B chromosome-specific DNA revealed a strong homology to a Drosophila Gypsy/Ty3 retrotransposon and also to a medaka (Oryzias latipes) one. The sequence is highly abundant on the B chromosome but undetectable in the normal A chromosome complement. It is also absent from the B chromosome of the closely related species, Rutilus rutilus, suggesting a specific spreading of the mobile element during evolution of the giant supernumerary chromosome within A. alburnus. Meitotic chromosomes were in-situ hybridized with the B chromosome-specific probe, documenting that the additional chromosome behaves as an autopaired ring chromosome in diakineses. Our results suggest that the supernumerary chromosome of A. alburnus is not derived from the normal chromosome complement but has evolved independently. 相似文献
11.
Using fluorescence in-situ hybridization on interphase chromatin fibers (fiber-FISH), we have constructed an overlapping fiber-FISH contig spanning the non-recombining region of the human Y chromosome (NRY). We first established a standard FISH-signal pattern for a distinct panel of DNA clones on prometaphase Y chromosomes in six healthy fertile men. Clones in the panel were selected from all R-bands as well as deletion intervals 1 through 7 plus PAR1 and PAR2 of the human Y chromosome. We next used signals of these marker clones to build a fiber-FISH contig for the multicopy gene families, CDY, DAZ, RBMY, TSPY and XKRY, along the NRY. Our fiber-FISH contig of human NRY may help to close the four gaps that still exist in the current physical map of the human Y chromosome. Furthermore, it provides a more complete picture with respect to the positions and arrangements of the multicopy gene families along the human NRY. 相似文献
12.
Summary The genes encoding the 17S, 5.8S and 25S ribosomal RNAs in the Ascomycete Cochliobolus heterostrophus were cloned and analyzed. They are arranged in tandemly repeated units (rDNA) either 9.0 or 9.15 kilobases in length, depending upon the strain. The 5S rRNA genes are not part of the tandemly repeated rDNA. Instead, many and perhaps all of the 5S genes are dispersed in the genome, as they are in the fungi Neurospora, Aspergillus and Schizosaccharomyces. Comparative restriction maps of the rDNA from C. heterostrophus and other filamentous fungi and yeasts are presented. A survey of rDNAs from twenty-three field isolates of C. heterostrophus collected worldwide demonstrated that each isolate has one or the other of two rDNA forms, which differ in length and in the presence or absence of at least three restriction enzyme sites. The differences are all located in spacer DNA outside the coding regions for the rRNA genes. Heterogeneity in the rDNA repeat was not observed within any single isolate. The copy number of the rRNA gene cluster in C. heterostrophus is approximately 130 per haploid genome. 相似文献
13.
Legumes are of immense importance as food and feed, and for sustainable agriculture, due to their ability to fix nitrogen.
Here, the chromosome maps of the legumes soybean (Glycine max), Lotus (Lotus japonicus), and red clover (Trifolium pratense) are reviewed. These species have relatively small chromosomes and therefore are difficult to exploit for chromosome studies.
Nevertheless, the identification of individual chromosomes became feasible, and chromosome maps have been developed applying
image analysis and fluorescence in-situ hybridization. For Lotus japonicus, e.g. detailed chromosome maps have been developed using the information of genetic linkage maps. Future prospects of further
legume chromosome mapping for breeding and genetic purposes are discussed. 相似文献
14.
Lurdes F. de Almeida-Toledo M. F. Z. Daniel-Silva C. E. Lopes Silvio de A. Toledo-Filho 《Chromosome research》2000,8(4):335-340
A multiple sex chromosome system of the X1X1X2X2:X1X2Y type is reported to occur in the fish species Brachyhypopomus pinnicaudatus (Gymnotiformes, Hypopomidae), being the second occurrence of this sex chromosome system in Gymnotiformes and the fifth among
Neotropical freshwater fish. The possible origin of this system was hypothesized to be a centric fusion, which occurred in
an ancestral form, of two medium-sized acrocentrics, giving origin to the metacentric neo-Y. Heterochromatic DAPI-positive
regions were visualized in the pericentromeric region of all the chromosomes, including the Y-chromosome. In-situ hybridization with (TTAGGG)
n
(all-human-telomeres probe) did not detect any telomeric interstitial regions (ITS), indicating a possible loss of terminal
segments of the chromosomes involved in the neo-Y formation.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
15.
Takahiro Taguchi Kunihiro Akimaru Hirohisa Hirai Yuriko Hirai Jason M. Mwenda Kazunari Yuri 《Chromosome research》2003,11(2):147-152
We isolated a DNA probe, designated MMDYZ1, using a chromosome microdissection technique from the Y chromosome of the Rhesus monkey. The probe obtained from eight whole Y chromosomes shows higher specificity for the Y short arm of the Rhesus monkey, which consists totally of constitutive heterochromatin. Two microclones (MMY#3 and MMY#4) were constructed from the Y-specific primary PCR products. Sequence analysis of these two microclones revealed that both were essentially identical to each other and the sizes were 870 and 686bp, respectively. From alignment analysis using the Genbank database of primates, the alphoid DNA has the highest affinity with the probe. However, the total composition of this probe has extremely high homology with the Y short arm of the Rhesus monkey, as demonstrated by fluorescence in-situ hybridization (FISH). Comparative FISH-mapping disclosed that this DNA-sequence cluster was located at extremely different sites on the Y chromosome in several species of the Old World monkey. Accordingly, this probe seems to be a high-quality tool, now established for the first time, for investigating Y chromosome evolution of the Old World monkey. 相似文献
16.
The ribosomal DNA arrays in the nucleolar organizer regions (NORs) of aphids are generally located in a telomeric or subtelomeric position on the X chromosomes. In aphid populations or species that have lost the sexual part of their life cycle and become permanent apomicts, multiple rDNA copies are often concentrated on only one of the original X chromosomes. This situation has been found in apomictic members of three aphid subfamilies, although not as yet in the tribe Aphidini, which includes several permanent apomicts that are important pests. Some clonal cultures ofAcyrthosiphon pisum andMyzus persicae reared for many years in conditions that prolong apomixis and inhibit sexual reproduction also have their rDNA arrays concentrated on one X chromosome. A 50-year-old clone ofAphis fabae, however, still retains a pair of similar-sized rDNA arrays on its X chromosomes. Although pairing of the X chromosomes by their NORs during prophase of the maturation division seems to be required for determination of XO males in aphids, a clone ofA. pisum with one rDNA array was nevertheless able to produce males when subjected to appropriate environmental conditions.accepted for publication by H. C. Macgregor 相似文献
17.
Gianfranco Coppola Basil Alexander Dino Di Berardino Elizabeth St John Parvathi K. Basrur W. Allan King 《Chromosome research》2007,15(3):399-408
Causes of chromosomal differences such as mosaicism between embryos developed in vivo and in vitro may be resolved using animal models to compare embryos generated in vivo with those generated by different production systems. The aims of this study were: (1) to test a ZOO-FISH approach (using
bovine painting probes) to detect abnormal chromosome make-up in the sheep embryo model, and (2) to examine the extent of
chromosome deviation in sheep embryos derived in vivo and in vitro. Cytogenetic analysis was performed on day 6 in-vivo and in-vitro derived sheep embryos using commercially available bovine chromosome painting probes for sex chromosomes X–Y and autosomes
1–29. A total of 8631 interphase and metaphase nuclei were analyzed from 49 in-vitro-derived and 51 in-vivo-derived embryos. The extent of deviation from normal ovine chromosome make-up was higher (p < 0.05) in in-vitro-produced embryos relative to in-vivo-derived embryos (65.3% vs. 19.6% respectively) mainly due to diploid–polyploid mosaicism. Polyploid cells ranged from 3n
to 8n with tetraploids most predominant among non-diploid cells. The proportions of polyploid cells per mixoploid embryo in
in-vitro-produced embryos ranged from 1.4% to 30.3%, in contrast to less than 10% among the in-vivo-derived embryos. It was concluded that in-vitro-derived embryos are vulnerable to ploidy change compared to their in-vivo counterparts. The application of ZOO-FISH to domestic animal embryos is an effective approach to study the chromosome complement
of species for which DNA probes are unavailable. 相似文献
18.
Triploid origin of the gibel carp as revealed by 5S rDNA localization and chromosome painting 总被引:2,自引:0,他引:2
5S ribosomal DNA (rDNA) was isolated and sequenced from the gibel carp Carassius auratus gibelio with 162 chromosomes and crucian carp Carassius auratus with 100 chromosomes, and fluorescent probes for chromosome localization were prepared to ascertain the ploidy origin and
evolutionary relationship between the two species. Using fluorescence in-situ hybridization (FISH), major 5S rDNA signals were localized to the short arms of three subtelocentric chromosomes in the gibel
carp and to the short arms of two subtelocentrics in the crucian carp. In addition, some minor signals were detected on other
chromosomes of both species. Simultaneously, six chromosomes were microdissected from the gibel carp metaphase spreads using
glass needles, and the isolated chromosomes were amplified in vitro by degenerate oligonucleotide primed-polymerase chain reaction (DOP-PCR). Significantly, when the DOP-PCR-generated probes
prepared from each single chromosome were hybridized, three same-sized chromosomes were painted in each gibel carp metaphase,
whereas only two painted chromosomes were observed in each crucian carp metaphase spread. The data indicate that gibel carp
is of triploid origin in comparison with diploid crucian carp. 相似文献
19.
We investigated chromosome evolution in Nemesia using fluorescent in-situ hybridization (FISH) to identify the locations of 5S and 45S (18–26S) ribosomal genes. Although there was conservation between
Nemesia species in chromosome number, size and centromere position, there was large variation in both number and position of ribosomal
genes in different Nemesia species (21 different arrangements of 45S and 5S rRNA genes were observed in the 29 Nemesia taxa studied). Nemesia species contained between one and three pairs of 5S arrays and between two and four pairs of 45S arrays. These were either
sub-terminally or interstitially located and 45S and 5S arrays were often located on the same chromosome pair. Comparison
of the positions of rDNA arrays with meiotic chromosome behaviour in interspecific hybrids of Nemesia suggests that some of the changes in the positions of rDNA have not affected the surrounding chromosome regions, indicating
that rDNA has changed position by transposition. Chromosome evolution is frequently thought to occur via structural rearrangements
such as inversions and translocations. We suggest that, in Nemesia, transposition of rDNA genes may be equally if not more important in chromosome evolution. 相似文献