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1.
Pedro Jara-Seguel Cristina Zúñiga Mario Romero-Mieres Claudio Palma-Rojas Elisabeth von Brand 《Biologia》2010,65(5):813-816
The karyotype of Luzuriaga radicans R. & P. was quantitatively studied, assessing characters such as chromosome morphology and size, satellite location, asymmetry
level and bimodality. L. radicans has an asymmetric and bimodal karyotype 2n = 20 with three metacentric pairs, followed by six submetacentric and one subtelocentric chromosome pair. One satellite was
observed in the short arm of chromosome pair 6. The total haploid set length was 48.7 μm and the mean chromosome size was
4.87 ± 2.35 μm. Comparing L. radicans with other two species of the genus a high resemblance among their karyotypes was found. 相似文献
2.
Several chromosome types have been recognized in Citrus and related genera by chromomycin A3 (CMA) banding patterns and fluorescent in situ hybridization (FISH). They can be used to characterize cultivars and species
or as markers in hybridization and backcrossing experiments. In the present work, characterization of six cultivars of P. trifoliata (“Barnes”, “Fawcett”, “Flying Dragon”, “Pomeroy”, “Rubidoux”, “USDA”) and one P. trifoliata × C. limonia hybrid was performed by sequential analyses of CMA banding and FISH using 5S and 45S rDNA as probes. All six cultivars showed
a similar CMA+ banding pattern with the karyotype formula 4B + 8D + 6F. The capital letters indicate chromosomal types: B, a chromosome
with one telomeric and one proximal band; D, with only one telomeric band; F, without bands. In situ hybridization labeling
was also similar among cultivars. Three chromosome pairs displayed a closely linked set of 5S and 45S rDNA sites, two of them
co-located with the proximal band of the B type chromosomes (B/5S-45S) and the third one co-located with the terminal band
of a D pair (D/5S-45S). The B/5S-45S chromosome has never been found in any citrus accessions investigated so far. Therefore,
this B chromosome can be used as a marker to recognize the intergeneric Poncirus × Citrus hybrids. The intergeneric hybrid analyzed here displayed the karyotype formula 4B + 8D + 6F, with two chromosome types B/5S-45S
and two D/5S-45S. The karyotype formula and the presence of two B/5S-45S chromosomes clearly indicate that the plant investigated
is a symmetric hybrid. It also demonstrates the suitability of karyotype analyses to differentiate zygotic embryos or somatic
cell fusions involving trifoliate orange germplasm.
During the submission of this paper, we analyzed 25 other citrus cultivars with the same methodology and we found that the
chromosome marker reported here can indeed distinguish Poncirus trifoliata from grapefruits, pummelos, and one variegated access of Citrus, besides the previously reported access of limes, limons, citrons, and sweet-oranges. However, among 14 mandarin cultivars,
two of them displayed a single B/5S-45S chromosome, whereas in Citrus hystrix D.C., a far related species belonging to the Papeda subgenus, this chromosome type was found in homozygosis. Since these two mandarin cultivars are probably of hybrid origin,
we assume that for almost all commercial cultivars and species of the subgenus Citrus this B type chromosome is a useful genetic marker. 相似文献
3.
Huseyin Inceer Sema Hayirlioglu-Ayaz Halil Selim Guler Nursen Aksu Melahat Ozcan 《Plant Systematics and Evolution》2012,298(4):827-834
The karyotypes of nine Tanacetum taxa distributed in north-east Anatolia, Turkey, were determined and evaluated by cluster analysis and principal-components
analysis. Chromosome numbers were 2n = 2x = 18 (8 taxa) and 4x = 36 (1 taxon). Somatic chromosome numbers of two taxa and a new ploidy level in one taxon are reported for the first time.
Karyotype analysis indicated that chromosomes of Tanacetum taxa have predominantly median centromeres. The taxa studied differed significantly in the size of the short arms and long
arms, and the arm ratio of each pair of homologous chromosomes, indicating structural rearrangements of the chromosomes have
been involved in diversification of the taxa. They were placed in 2A, 3A, and 2B of Stebbins’ karyotype classification, showing
the presence of a primitive symmetrical karyotype in the genus. Several systematic and evolutionary aspects of the genus are
discussed on the basis of karyological data. 相似文献
4.
Multicolor FISH mapping of the dioecious model plant,<Emphasis Type="Italic"> Silene latifolia</Emphasis> 总被引:8,自引:0,他引:8
Lengerova M Kejnovsky E Hobza R Macas J Grant SR Vyskot B 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,108(7):1193-1199
Silene latifolia is a key plant model in the study of sex determination and sex chromosome evolution. Current studies have been based on genetic mapping of the sequences linked to sex chromosomes with analysis of their characters and relative positions on the X and Y chromosomes. Until recently, very few DNA sequences have been physically mapped to the sex chromosomes of S. latifolia. We have carried out multicolor fluorescent in situ hybridization (FISH) analysis of S. latifolia chromosomes based on the presence and intensity of FISH signals on individual chromosomes. We have generated new markers by constructing and screening a sample bacterial artificial chromosome (BAC) library for appropriate FISH probes. Five newly isolated BAC clones yielded discrete signals on the chromosomes: two were specific for one autosome pair and three hybridized preferentially to the sex chromosomes. We present the FISH hybridization patterns of these five BAC inserts together with previously described repetitive sequences (X-43.1, 25S rDNA and 5S rDNA) and use them to analyze the S. latifolia karyotype. The autosomes of S. latifolia are difficult to distinguish based on their relative arm lengths. Using one BAC insert and the three repetitive sequences, we have constructed a standard FISH karyotype that can be used to distinguish all autosome pairs. We also analyze the hybridization patterns of these sequences on the sex chromosomes and discuss the utility of the karyotype mapping strategy presented to study sex chromosome evolution and Y chromosome degeneration.Communicated by J.S. Heslop-Harrison 相似文献
5.
Two congeneric mullet species, Mugil liza and M. curema, respectively with an all-uniarmed and an all-biarmed karyotype, were cytogenetically studied by base-specific fluorochrome staining and FISH-mapping of 45S and 5S ribosomal RNA genes (rDNA) and the (TTAGGG)n telomeric repeats. Whereas 45S rDNA sites might be homeologus in the two species, 5S rDNA sites are not, as they are localized on chromosome arms of different size. In both species, the (TTAGGG)n telomeric probe hybridized to natural telomeres and was found scattered along the NORs. In metacentric chromosomes of M. curema, no pericentromeric signals of the telomeric probe were detected. Data are discussed in relation to the karyotype evolution in Mugilidae and to the mechanisms and the evolutionary implications of Robertsonian rearrangements in M. curema. 相似文献
6.
We describe the chromosomal location of GC-rich regions, 28S and 5S rDNA, core histone genes, and telomeric sequences in the
veneroid bivalve species Venerupis aurea and Tapes (Venerupis) rhomboides, using fluorochrome staining with propidium iodide, DAPI and chromomycin A3 (CMA) and fluorescent in situ hybridization (FISH).
DAPI dull/CMA bright bands were coincident with the chromosomal location of 28S rDNA in both species. The major rDNA was interstitially
clustered at a single locus on the short arms of the metacentric chromosome pair 5 in V. aurea, whereas in T. rhomboides it was subtelomerically clustered on the long arms of the subtelocentric chromosome pair 17. 5S rDNA also was a single subtelomeric
cluster on the long arms of subtelocentric pair 17 in V. aurea and on the short arms of the metacentric pair 9 in T. rhomboides. Furthermore, V. aurea showed four telomeric histone gene clusters on three metacentric pairs, at both ends of chromosome 2 and on the long arms
of chromosomes 3 and 8, whereas histone genes in T. rhomboides clustered interstitially on the long arms of the metacentric pair 5 and proximally on the long arms of the subtelocentric
pair 12. Double and triple FISH experiments demonstrated that rDNA and H3 histone genes localized on different chromosome
pairs in the two clam species. Telomeric signals were found at both ends of every single chromosome in both species. Chromosomal
location of these three gene families in two species of Veneridae provides a clue to karyotype evolution in this commercially
important bivalve family. 相似文献
7.
Paratelmatobius and Scythrophrys are leptodactylid frogs endemic to the Brazilian Atlantic forest and their close phylogenetic relationship was recently inferred
in an analysis that included Paratelmatobius sp. and S. sawayae. To investigate the interspecific relationships among Paratelmatobius and Scythrophrys species, we analyzed a mitochondrial region (approximately 2.4 kb) that included the ribosomal genes 12S and 16S and the
tRNAval in representatives of all known localities of these genera and in 54 other species. Maximum parsimony inferences were
done using PAUP* and support for the clades was evaluated by bootstrapping. A cytogenetic analysis using Giemsa staining,
C-banding and silver staining was also done for those populations of Paratelmatobius not included in previous cytogenetic studies of this genus in order to assess their karyotype differentiation. Our results
suggested Paratelmatobius and Scythrophrys formed a clade strongly supported by bootstrapping, which corroborated their very close phylogenetic relationship. Among
the Paratelmatobius species, two clades were identified and corroborated the groups P.
mantiqueira and P. cardosoi previously proposed based on morphological characters. The karyotypes of Paratelmatobius sp. 2 and Paratelmatobius sp. 3 described here had diploid chromosome number 2n = 24 and showed many similarities with karyotypes of other Paratelmatobius representatives. The cytogenetic data and the phylogenetic analysis allowed the proposal/corroboration of several hypotheses
for the karyotype differentiation within Paratelmatobius and Scythrophrys. Namely the telocentric pair No. 4 represented a synapomorphy of P. cardosoi and Paratelmatobius sp. 2, while chromosome pair No. 5 with interstitial C-bands could be interpreted as a synapomorphy of the P. cardosoi group. The NOR-bearing chromosome No. 10 in the karyotype of P. poecilogaster was considered homeologous to chromosome No. 10 in the karyotype of Scythrophrys sp., chromosome No. 9 in the karyotype of Paratelmatobius sp. 1, chromosome No. 8 in the karyotypes of Paratelmatobius sp. 2 and of Paratelmatobius sp. 3, and chromosome No. 7 in the karyotype of P. cardosoi. A hypothesis for the evolutionary divergence of these NOR-bearing chromosomes, which probably involved events like gain
in heteochromatin, was proposed. 相似文献
8.
Radim Cegan Gabriel AB Marais Hana Kubekova Nicolas Blavet Alex Widmer Boris Vyskot Jaroslav Doležel Jan Šafář Roman Hobza 《BMC plant biology》2010,10(1):180
Background
The evolution of sex chromosomes is often accompanied by gene or chromosome rearrangements. Recently, the gene AP3 was characterized in the dioecious plant species Silene latifolia. It was suggested that this gene had been transferred from an autosome to the Y chromosome. 相似文献9.
Koo DH Plaha P Lim YP Hur Y Bang JW 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,109(7):1346-1352
A molecular cytogenetic map of Chinese cabbage (Brassica rapa ssp. pekinensis, 2n=20) was constructed based on the 4-6-diamino-2-phenylindole dihydrochloride-stained mitotic metaphase and pachytene chromosomes and multicolor fluorescence in situ hybridization (McFISH), using three repetitive DNA sequences, 5S rDNA, 45S rDNA, and C11-350H. The lengths of mitotic metaphase chromosomes ranged from 1.46 m to 3.30 m. Five 45S and three 5S rDNA loci identified were assigned to different chromosomes. The C11-350H loci were located on all the mitotic metaphase chromosomes, except chromosomes 2 and 4. The pachytene karyotype consisted of two metacentric (chromosomes 1 and 6), five submetacentric (chromosomes 3, 4, 5, 9 and 10), two subtelocentric (chromosomes 7 and 8), and one acrocentric (chromosome 2) chromosome(s). The mean lengths of ten pachytene chromosomes ranged from 23.7 m to 51.3 m, with a total of 385.3 m, which is 17.5-fold longer than that of the mitotic metaphase chromosomes. In the proposed pachytene karyotype, all the chromosomes of B. rapa ssp. pekinensis can be identified on the basis of chromosome length, centromere position, heterochromatin pattern, and the location of the three repetitive sequences. Moreover, the precise locations of the earlier reported loci of 5S rDNA, 45S rDNA, and Chinese cabbage tandem DNA repeat C11-350H were established using McFISH analysis. We also identified a 5S rDNA locus on the long arm of pachytene bivalent 7, which could not be detected in the mitotic metaphase chromosomes in the present and earlier studies. The deduced karyotype will be useful for structural and functional genomic studies in B. rapa. 相似文献
10.
Eric Mortreau Sonia Siljak-Yakovlev Malika Cerbah Spencer C. Brown Hélène Bertrand Claudie Lambert 《Tree Genetics & Genomes》2010,6(1):137-148
The subsection Asperae of genus Hydrangea L. (Hydrangeaceae) has been investigated for three reasons: several ambiguous classifications concerning Hydrangea aspera have been published, unexpected differences in genome size among seven accessions have been reported Cerbah et al. (Theor
Appl Genet 103:45–51, 2001), and two atypical chromosome numbers (2n = 30 for Hydrangea involucrata and 2n = 34 for H. aspera) have been found when all other species of the genus present 2n = 36. Therefore, these two species and four subspecies of Hydrangea in all 29 accessions were analyzed for their genome size, chromosome number, and karyotype features. This investigation includes
flow cytometric measurements of nuclear DNA content and bases composition (GC%), fluorochrome banding for detection of GC-
and AT-rich DNA regions, and fluorescent in situ hybridisation (FISH) for chromosome mapping of 5 S and 18 S-5.8 S-26 S rDNA
genes. In the H. aspera complex, the genome size ranged from 2.98 (subsp. sargentiana) to 4.67 pg/2C (subsp. aspera), an exceptional intraspecific variation of 1.57-fold. The mean base composition was 40.5% GC. Our report establishes the
first karyotype for the species H. involucrata, and for the subspecies of H. aspera which indeed present different formulae, offering an element of discrimination. FISH and fluorochrome banding revealed the
important differentiation between these two species (H. involucrata and H. aspera) and among four subspecies of the H. aspera complex. Our results are in agreement with the Chinese classification that places the groups Kawakami and Villosa as two
different species: Hydrangea villosa Rehder and Hydrangea kawakami Hayata. This knowledge can contribute to effective germplasm management and horticultural use. 相似文献
11.
Dioecious Silene latifolia evolved heteromorphic sex chromosomes within the last ten million years, making it a species of choice for studies of the
early stages of sex chromosome evolution in plants. About a dozen genes have been isolated from its sex chromosomes and basic
genetic and deletion maps exist for the X and Y chromosomes. However, discrepancies between Y chromosome maps led to the proposal
that individual Y chromosomes may differ in gene order. Here, we use an alternative approach, with fluorescence in situ hybridization
(FISH), to locate individual genes on S. latifolia sex chromosomes. We demonstrate that gene order on the Y chromosome differs between plants from two populations. We suggest
that dynamic gene order may be a general property of Y chromosomes in species with XY systems, in view of recent work demonstrating
that the gene order on the Y chromosomes of humans and chimpanzees are dramatically different. 相似文献
12.
Diogo Cavalcanti Cabral-de-Mello Rita de Cássia de Moura Maria José de Souza 《Genetica》2010,138(2):191-195
13.
Silene latifolia is a model plant for studies of the early steps of sex chromosome evolution. In comparison to mammalian sex chromosomes that
evolved 300 mya, sex chromosomes of S. latifolia appeared approximately 20 mya. Here, we combine results from physical mapping of sex-linked genes using polymerase chain
reaction on microdissected arms of the S. latifolia X chromosome, and fluorescence in situ hybridization analysis of a new cytogenetic marker, Silene tandem repeat accumulated on the Y chromosome. The data are interpreted in the light of current genetic linkage maps of the
X chromosome and a physical map of the Y chromosome. Our results identify the position of the centromere relative to the mapped
genes on the X chromosome. We suggest that the evolution of the S. latifolia Y chromosome has been accompanied by at least one paracentric and one pericentric inversion. These results indicate that
large chromosomal rearrangements have played an important role in Y chromosome evolution in S. latifolia and that chromosomal rearrangements are an integral part of sex chromosome evolution. 相似文献
14.
Puerma E Acosta MJ Barragán MJ Martínez S Marchal JA Bullejos M Sánchez A 《Genetica》2008,134(3):287-295
The karyotype of individuals of the species Rhinolophus hipposideros from Spain present a chromosome number of 2n = 54 (NFa = 62). The described karyotype for these specimens is very similar to another previously described in individual
from Bulgaria. However, the presence of one additional pair of autosomal acrocentric chromosomes in the Bulgarian karyotype
and the differences in X chromosome morphology indicated that we have described a new karyotype variant in this species. In
addition, we have analyzed several clones of 1.4 and 1 kb of a PstI repeated DNA sequence from the genome of R. hipposideros. The repeated sequence included a region with high identity with the 5S rDNA genes and flanking regions, with no homology
with GenBank sequences. Search for polymerase III regulatory elements demonstrated the presence of type I promoter elements
(A-box, Intermediate Element and C-box) in the 5S rDNA region. In addition, upstream regulatory elements, as a D-box and Sp1
binding sequences, were present in flanking regions. All data indicated that the cloned repeated sequences are the functional
rDNA genes from this species. Finally, FISH demonstrated the presence of rDNA in nine chromosome pairs, which is surprising
as most mammals have only one carrier chromosome pair. 相似文献
15.
The karyotype of diploid Aster iinumae is morphologically similar to that of diploid Aster ageratoides var. ageratoides, however, its chromosome size is apparently smaller (S-type chromosomes versus L-type chromosomes, respectively). The hybrid
origin of tetraploid Aster microcephalus var. ovatus (LS-type chromosomes) has previously been suggested by cytogenetics and chloroplast DNA (cp DNA) data. The cp DNA phylogeny
also implies that the S-type chromosome is apomorphic, which means that genome size reduction occurred on the evolutionary
way to A. iinumae. In this study, we have demonstrated that the chromosome size difference does not depend on the intensity of chromosome condensation
but on the DNA content. The simultaneous genomic in situ hybridization (GISH) results show the similarity between S-type chromosomes
of A. iinumae and A. microcephalus var. ovatus, and between L-type chromosomes of A. ageratoides and A. microcephalus var. ovatus, which provide additional evidence for A. microcephalus var. ovatus being a tetraploid amphidiploid produced by hybridization between S-type chromosomes and L-type chromosomes. The distribution
patterns of Ty1-copia-like retrotransposons were similar in L- and S-type chromosomes. The copies of this retrotransposon dispersed uniformly on
all chromosomes, and it is not yet apparent how the Ty1-copia-like retrotransposon affects the size difference between them. 相似文献
16.
On the family Brassicaceae, the causal agent responsible for downy mildew disease was originally regarded as a single species,
Peronospora parasitica (now under Hyaloperonospora), but it was recently reconsidered to consist of many distinct species. In this study, 11 specimens of Peronospora
drabae and P. norvegica parasitic on the genus Draba were investigated morphologically and molecularly. Pronounced differences in conidial sizes (P. drabae: 14–20 × 12.5–15.5 μm; P. norvegica: 20–29 × 15.5–22 μm) and 7.8% sequence distance between their ITS1-5.8S-ITS2 rDNA sequences confirmed their status as distinct
species. Based on ITS phylogeny and morphology (monopodially branching conidiophores, flexuous to sigmoid ultimate branchlets,
hyaline conidia and lobate haustoria), the two species unequivocally belong to the genus Hyaloperonospora and not to Peronospora to which they were previously assigned. Therefore, two new combinations, Hyaloperonospora drabae and H. norvegica, are proposed. The two taxa are illustrated and compared using the type specimen for H. norvegica and authentic specimens for H. drabae, which is lectotypified. 相似文献
17.
V. G. Mitrofanov A. I. Chekunova E. S. Zelentsova L. N. Gauze G. N. Bakhtoyarov 《Cell and Tissue Biology》2011,5(5):440-443
The Dras1 gene was mapped by in situ hybridization to polytene chromosomes of several sibling species of the Drosophila virilis group and their hybrids. A 1037-bp fragment of Dras1 gene from the D. virilis genome was used as the probe. The gene sequence was localized in the region of a 25 A-B disk in chromosome 2 (in accordance
with the D. virilis polytene chromosome map (Gubenko and Evgen’ev, 1984). 相似文献
18.
The karyotype of Vaillantella maassi, a loach with an unusually long dorsal fin, was investigated using sequential CMA3 and AgNO3 staining to test if this character evolved in parallel with Vaillantella’s morphological distinctness. The karyotype was 2n = 50 with 13 pairs of metacentric-submetacentric and 12 pairs of subtelocentric chromosomes. Sequential CMA3 banding and AgNO3 staining evidenced NORs in the short arms of pair no. 2. Additional CMA3-positive, Ag-negative signals were present in the short arms of pairs 14 and 15. The karyotype paralleled those of most other
cobitoid loaches studied so far and is apparently not associated with the morphological distinctness of Vaillantella. 相似文献
19.
A new species of Hirsutella, H. proturicola, isolated from a subterranean proturan (Baculentulus densus; Protura, Hexapoda), is described and illustrated. Hirsutella proturicola is characterized by producing monoblastic phialides of 24–51.5 × 2.5–5 μm with a slightly roughened neck, fusiform and curved
conidia of 9–18 × 2.5–4 μm that have a truncate base and a papillate projection often capped with sheath-like mucilage, and
pluricellular, globose to subglobose chlamydospores of 21–48 × 21–41.5 μm. This species is morphologically and phylogenetically
close to H. rostrata, an acaropathogenic species, but can be distinguished from the size of the phialides and the size and shape of the conidia. 相似文献
20.
Although resistance of microorganisms to Hg(II) salts has been widely investigated and resistant strains have been reported
from many eubacterial genera, there are few reports of mercuric ion resistance in extremophilic microorganisms. Moderately
thermophilic mercury resistant bacteria were selected by growth at 62 °C on Luria agar containing HgCl2. Sequence analysis of 16S rRNA genes of two isolates showed the closest matches to be with Bacillus pallidus and Ureibacillus thermosphaericus. Minimum inhibitory concentration (MIC) values for HgCl2 were 80 μg/ml and 30 μg/ml for these isolates, respectively, compared to 10 μg/ml for B. pallidus H12 DSM3670, a mercury-sensitive control. The best-characterised mercury-resistant Bacillus strain, B. cereus RC607, had an MIC of 60 μg/ml. The new isolates had negligible mercuric reductase activity but removed Hg from the medium
by the formation of a black precipitate, identified as HgS by X-ray powder diffraction analysis. No volatile H2S was detected in the headspace of cultures in the absence or presence of Hg2+, and it is suggested that a new mechanism of Hg tolerance, based on the production of non-volatile thiol species, may have
potential for decontamination of solutions containing Hg2+ without production of toxic volatile H2S. 相似文献