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1.
The somatic chromosome number of three Japanese species ofIsoetes, I. asiatica, I. japonica andI. sinensis, was determined in 199 individuals from 49 populations. The chromosome number ofI. asiatica was 2n=22, confirming previous reports. However,I. japonica andI. sinensis displayed a diversity in chromosome number. Six cytotypes, 2n=66, 67, 77, 87, 88 and 89, were found inI. japonica; 2n=67, 87, 88 and 89 are new counts in the genusIsoetes. The plants with 2n=66 were the most frequent (72% of total individuals examined) and were distributed throughout Honshu and Shikoku. The plants
with 2n=88 occurred in western Honshu and a limited region in northeastern Honshu where the plants with 2n=77 were also found. In contrast, four cytotypes, 2n=44, 65, 66 and 68, were found inI. sinensis. The chromosome numbers ofI. sinensis were reported here for the first time. The plants with 2n=44 occurred only in Kyushu, while the plants with 2n=66 were found throughout a large area of western Japan. 相似文献
2.
Reported in this paper is a karyomorphological study on one natural population of each of eight varieties in theSpiraea japonica complex. The interphase and mitotic prophase can be classified into the simple chromocenter type and the proximal type, respectively.
The metaphase karyotypes of the eight varieties were formulated as follows:S. japonica var.japonica: 2n=18=14m+2sm+2st;S. japonica var.acuta: 2n=18=11m+4sm+3st;S. japonica var.incisa: 2n=18=12m+4sm+2st;S. japonica var.stellaris: 2n=18=15m+1sm+2st;S. japonica var.acuminata: 2n=18=14m+2sm+2st;S. japonica var.ovalifolia: 2n=18=10m+2sm+2st+4t;S. japonica var.glabra: 2n=18=10m+4sm+4st;S. japonica var.fortunei: 2n=36=17m+16sm+3st. Karyomorphological study reveals that the chromosome numbers within the complex are stable, and that karyomorphological
divergence between the varieties lies mainly in chromosome size and organization. Based on the karyomorphological data and
geographical distribution of the complex, the differentiation pattern as well as evolutionary mechanism of the complex is
evaluated. 相似文献
3.
Ya-Juan Li Yi Tian Ming-Zhao Zhang Ping-Ping Tian Zhuo Yu Syuiti Abe Katsutoshi Arai 《Ichthyological Research》2010,57(4):358-366
The chromosomes of the diploid and tetraploid loach Misgurnus anguillicaudatus were analyzed by staining with Ag, chromomycin A3 (CMA3)/distamycin A (DA), and DA/4′,6-diamidino-2-phenylindole (DAPI), and using fluorescence in situ hybridization (FISH) with
5.8S + 28S rDNA as a probe. Nucleolus organizer regions (NORs) were mapped to the telomeric region of the short arms of the
largest (first) metacentric chromosome pair in the diploid loach with 2n = 50 and the homologous quartet in the tetraploid loach with 4n = 100. The NORs were positive at the same region of the first metacentric chromosome for Ag and CMA3/DA stainings, but negative for DA/DAPI staining. Four signals at the homologs within the same quartet suggest the duplication
of the entire genome from diploid to tetraploid status. However, a size difference was detected between the rDNA signals by
FISH and CMA3 banding. 相似文献
4.
The number and position of 18S–25S rDNA sites in 4 selected Lupinus species are reported for the first time. L. atlanticus, L. subcarnosus and L. paniculatus had two rDNA loci, while L. albus exhibited only one loci. Among these 4 species, all of them exhibited one large pair of strong signals that extends from
the short arm to a NOR on a chromosome satellite. L. atlanticus, L. subcarnosus, L. paniculatus had one more locus of 18–25S rDNA, but a pair of weak hybridization signals were observed in L. paniculatus when 18S–25S rDNA was used as probe. The results are discussed in terms of the evolutionary relationships among these species. 相似文献
5.
We have examined morphological and chromosomal variation inFallopia sect.Reynoutria in Korea to clarify their taxonomic identities and to determine whether their morphological variability is associated with
ploidy levels. Principal components analysis (PCA) of individuals from 21 populations, using major distinguishing characters,
revealed the presence of four major entiries of sect.Reynoutria in Korea; these includeF. sachalinensis, F. japonica var.japonica, F. forbesii, and the Nonsan population consisting of presumed hybrids. Based on morphology, it is hypothesized that the Nonsan population
was probably derived from multiple hybridization events involving the three named taxa. The results also indicate thatF. forbesii is distinct fromF. japonica var.japonica. Polyploidy is more prevalent in sect.Reynoutria than has been previously recognized.Fallopia sachalinensis in Korea occurs as dodecaploids with 2n=132; our count is the first dodecaploid count for the species, and represents the highest chromosome number known in the
genus.Fallopia japonica var.japonica occurs as tetraploids (2n=44), hexaploids (2n=66), and octoploids (2n=88), whileF. forbesii occurs as hexaploids (2n=66) and octoploids (2n=88); our counts appear to be the first reported chromosome numbers forF. forbesii. Morphological analysis indicates that there is no apparent correlation between the ploidy levels in these taxa and the morphological
characters that we have considered in this study except that the tetraploids ofF. japonica var.japonica tend to have somewhat thicker leaves. 相似文献
6.
Muravenko OV Yurkevich OY Bolsheva NL Samatadze TE Nosova IV Zelenina DA Volkov AA Popov KV Zelenin AV 《Genetica》2009,135(2):245-255
Karyotypes of species sects. Linum and Adenolinum have been studied using C/DAPI-banding, Ag-NOR staining, FISH with 5S and
26S rDNA and RAPD analysis. C/DAPI-banding patterns enabled identification of all homologous chromosome pairs in the studied
karyotypes. The revealed high similarity between species L. grandiflorum (2n = 16) and L. decumbens by chromosome and molecular markers proved their close genome relationship and identified the chromosome number in L. decumbens as 2n = 16. The similarity found for C/DAPI-banding patterns between species with the same chromosome numbers corresponds with
the results obtained by RAPD-analysis, showing clusterization of 16-, 18- and 30-chromosome species into three separate groups.
5S rDNA and 26S rDNA were co-localized in NOR-chromosome 1 in the genomes of all species investigated. In 30-chromosome species,
there were three separate 5S rDNA sites in chromosomes 3, 8 and 13. In 16-chromosome species, a separate 5S rDNA site was
also located in chromosome 3, whereas in 18-chromosome species it was found in the long arm of NOR-chromosome 1. Thus, the
difference in localization of rDNA sites in species with 2n = 16, 2n = 30 and 2n = 18 confirms taxonomists opinion, who attributed these species to different sects. Linum and Adenolinum, respectively. The
obtained results suggest that species with 2n = 16, 2n = 18 and 2n = 30 originated from a 16-chromosome ancestor. 相似文献
7.
Polypteridae (Cladistia) is a family of archaic fishes, confined to African freshwaters. On account of their primitiveness
in anatomical and morphological characters and mosaic relationships among lower Osteichthyans fishes, they constitute an important
subject for the study of evolution in vertebrates. Very little is known about the karyological structure of these species.
In this article, a cytogenetic analysis on twenty specimens of Polypterus senegalus (Cuvier, 1829) was performed using both classical and molecular techniques. Karyotype (2n = 36; FN = 72), chromosome location of telomeric sequences (TTAGGG)
n
, (GATA)7 repeats and ribosomal 5S and 18S rRNA genes were examined by using Ag-NOR, classical C-banding, CMA3 staining and FISH. Staining with Ag-NOR showed the presence of two GC rich NORs on the p arm of the chromosome pair no. 1.
CMA3 marked all centromerical and some (no. 1 and no. 14) telomeric regions. FISH with 5S rDNA marked the subtelomeric region
of the q arm of the chromosome pair no. 14. FISH with 18S rDNA marked the telomeric region of the p arm of the chromosome
pair no. 1, previously marked by Ag-NOR. (GATA)7 repeats marked the subtelomeric regions of all chromosome pairs, with the exclusion of the no. 1, 3 and 14. Hybridization
with telomeric probes (TTAGGG)
n
showed bright signals at the end of all chromosomes. After cloning, the 5SrDNA alignment revealed an organization of sequences
made up of two different classes of tandem arrays (5S type I and 5S type II) of different lengths. 相似文献
8.
We compare the chromosomal 28S and 5S rDNA patterns of the spined loach C. taenia (2n = 48) from an exclusively diploid population and from a diploid–polyploid population using 28S and 5S rDNA probe preparation
and labelling, and fluorescence in situ hybridization (FISH). The 5S rDNA was located in two to three chromosome pairs, and separated from the 28S loci for the males
and one female (F1) from the diploid population. Loaches from a diploid–polyploid population, and one female (F2) from the
diploid population were characterized by at least one chromosome pair with 5S and 28S overlapping signals. The fishes differed
mainly in their number of 28S rDNA loci, located on 3–6 chromosomes. All individuals from both populations were characterized
by one acrocentric chromosome bearing a 28S rDNA signal on the telomeres of its long arm. The number of major ribosomal DNA
in the karyotype of C. taenia by FISH was always higher than the number of Ag-NORs. Our data confirm the extensive polymorphism of NORs in both populations,
as already has been observed in closely related Cobitis species, and less polymorphic 5S rDNA pattern. However, this preliminary result highlights the need for a wider scale study. 相似文献
9.
Huang Xiaoting; Hu Xiaoli; Hu Jingjie; Zhang Lingling; Wang Shi; Lu Wei; Bao Zhenmin 《Journal of Molluscan Studies》2007,73(4):393-398
The chromosome set of Patinopecten yessoensis (Jay, 1857) wascharacterized using Giemsa staining, DAPI staining and fluorescencein situ hybridization (FISH) with three repetitive DNA probes[18S–28S rDNA, 5S rDNA and telomeric (TTAGGG)n]. DAPIstaining showed that AT-rich regions were located on the centromereof almost all chromosomes and interstitial banding was not observed.FISH showed that 18S–28S rDNA spread over the short armsof two subtelocentric chromosome pairs and 5S rDNA was locatedon the long arm of one subtelocentric chromosome pair. SequentialFISH demonstrated that 18S–28S and 5S rDNA were locatedon different chromosomes. FISH also showed that the vertebratetelomeric sequence (TTAGGG)n was located on both ends of eachchromosome and no interstitial signals were detected. Sequential18S–28S rDNA and (TTAGGG)n FISH indicated that repeatedunits of the two multicopy families were closely associatedon the same chromosome pair. (Received 4 January 2007; accepted 1 September 2007) 相似文献
10.
To explore an effective and reliable karyotyping method in Brassica crop plants, Cot-1 DNA was isolated from Brassica oleracea genome, labeled as probe with Biotin-Nick Translation Mix kit, in situ hybridized to mitotic spreads, and where specific fluorescent bands showed on each chromosome pair. 25S and 5S rDNA were
labeled as probes with DIG-Nick Translation Mix kit and Biotin-Nick Translation Mix kit, respectively, in situ hybridized to mitotic preparations, where 25S rDNA could be detected on two chromosome pairs and 5S rDNA on only one. Cot-1 DNA contains rDNA and chromosome sites identity between Cot-1 DNA and 25S rDNA was determined by dual-colour fluorescence in situ hybridization. All these showed that the karyotyping technique based on a combination of rDNA and Cot-1 DNA chromosome landmarks is superior to all but one. A more exact karyotype of B. oleracea has been analyzed based on a combination of rDNA sites, Cot-1 DNA fluorescent bands, chromosome lengths and arm ratios.
__________
Translated from Journal of Wuhan University (Nat. Sci. Ed.), 2006, 52(2): 230–234 [译自: 武汉大学学报 (理学版)] 相似文献
11.
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
12.
Chromosome numbers are determined from 37 populations attributed to 22 taxa of JapaneseArisaema. Of them, chromosome numbers ofA. limbatum var.conspicuum (2n=26),A. minus (2n=26),A. nambae (2n=28) andA. seppikoense (2n=26) are determined for the first time. New chromosome numbers, 2n=26, are reported forA. aequinoctiale, A. limbatum, A. stenophyllum, A. undulatifolium andA. yoshinagae. Three modes of basic chromosome numbers,x=14,x=13 andx=12, occur in JapaneseArisaema. Precise karyotypic comparisons of 20 taxa reveal that taxa withx=14 andx=13 share 26 major chromosome arms and have an obvious chromosomal relationship. One of two submeta-centric chromosomes inx=13 corresponds to two telo-centric chromosomes inx=14. InA. ternatipartitum with 2n=6x=72, ten out of 12 basic chromosomes are the most similar in size and arm ratio with larger ten chromosomes ofA. ringens among JapaneseArisaema examined. A basic chromosome number ofx=14 is the commonest in the genusArisaema and the remaining basic chromosome numbers,x=13 andx=12, seem to be derived through dysploidal reduction by translocating large segments of major arm of telo-centric chromosome
onto other minor arm of telo-centric followed by loss of the remainings including a centromere, and by loss of two telo-centrics
fromx=14, respectively. Some systematic problems of JapaneseArisaema are discussed based on new cytological data.Arisaema hatizyoense, A. minus andA. nambae are accepted as independent species. 相似文献
13.
This work describes the karyotype and chromosomal location of the ribosomal DNA (rDNA) of Pecten maximus and Mimachlamys varia, two commercial scallop species from Europe. According to the chromosome centromeric index values found, the karyotype of
P. maximus is composed of 1 metacentric, 2 metacentric–submetacentric, 1 telocentric–subtelocentric and 15 telocentric pairs, and that
of M. varia of 4 metacentric, 2 subtelocentric–submetacentric, 9 subtelocentric, 3 subtelocentric–telocentric and 1 telocentric–subtelocentric
pairs. In P. maximus, 18S-28S rDNA was located by FISH on a metacentric–submetacentric pair, and in M. varia on a subtelocentric–submetacentric pair using both silver staining and FISH. PCR amplification of the 5S rDNA unit yielded
a single product of about 460 bp (P. maximus) and 450 bp (M. varia), that used as probe revealed a 5S rDNA site on a telocentric pair in P. maximus and a subtelocentric pair in M. varia. Two-color FISH or sequential silver staining of 5S rDNA-FISH-metaphases corroborated that the two gene families are located
on different chromosomes in both species. A comparative analysis of the data allowed the inference of karyotypic relationships
within scallops. 相似文献
14.
Kazuo Oginuma Masashi Nakata Mitsuo Suzuki Hiroshi Tobe 《Journal of plant research》1991,104(4):297-308
Karyomorphology ofCoriaria, the only genus of the family which is controversial with respect to its affinities and the number of constituting species,
is investigated on the basis of ten species (including eight narrowly defined species) representing nearly all the variation
of the genus. Features common to all the species investigated are: (1) interphase nucleus has a few small or large, condensed
heterochromatic blocks; (2) chromosomes at metaphase are mostly small (0.4–0.7 μm long by our methods); (3)x=20. Resemblances in chromosome morphology suggest that Coriariaceae may have affinities with Rutales/Sapindales. Differences
among species are found in (1) whether somatic chromosomes are diploid (2n=40) or tetraploid (2n=80); (2) the presence or absence of a few chromosomes with thick heterochromatic segments at metaphase; when such chromosomes
are present, (3) their number and (4) morphology. Karyomorphology defines wellCoriaria myrtifolia, C. napalensis andC. japonica, and further provides evidence for distinguishing at least four species withinC. ruscifolia sensu Skog. 相似文献
15.
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
16.
Karyotype, sex chromosome system and cytogenetics characteristics of an unidentified species of the genus Apareiodon originating from Piquiri River (Paraná State, Brazil) were investigated using differential staining techniques (C-banding
and Ag-staining) and fluorescent in situ hybridization (FISH) with 5S and 18S rDNA probes. The diploid chromosome number was 2n = 54 with 25 pairs of meta- (m) to submetacentric (sm) and 2 pairs of subtelocentric (st) chromosomes. The major ribosomal
rDNA sites as revealed by Ag-staining and FISH with 18S rDNA probe were found in distal region of longer arm of st chromosome
pair 26, while minor 5S sites were observed in the interstitial sites on chromosome pairs 2 (smaller cluster) and 7 (larger
one). The C-positive heterochromatin had pericentromeric and telomeric distribution. The heteromorphic sex chromosome system
consisted of male ZZ (pair 21) and female middle-sized m/st Z/W chromosomes. The pericentric inversion of heterochromatinized
short arm of ancestral Z followed by multiplication of heterochromatin segments is hypothesized for origin of W chromosome.
The observed karyotype and chromosomal markers corresponded to those found in other species of the genus. 相似文献
17.
Chromosome numbers were determined for 340 plants ofCarex conica from 83 populations in Japan. Six aneuploids, 2n=32, 33, 34, 36, 37 and 38, were found. Plants with even diploid chromosome numbers 2n=32, 34, and 36 were the most common and had different geographical distributions. Individuals with 2n=32 were from islands in the Seto Inland Sea and nearby coastal areas of the Chugoku District of Honshu; those with 2n=34 were from the Kanto, Chubu and Kinki Districts of Honshu; those with 2n=36 were from the mountainous areas of Chugoku, Shikoku and Kyushu Districts. Canonical discriminant analysis of 17 morphological
characters demonstrated that the plants with 2n=32 were clearly distinct from those with 2n=34 or 36. All four aneuploids with even chromosome numbers showed normal bivalent pairing at meiotic metaphase I and probably
represent cytogenetically stable cytodemes. Plants with 2n=33 had one heteromorphic trivalent and 15 bivalents, indicating a structural mutation. At mitotic metaphase I, one chromosome
was markedly larger than the others, suggesting that the 2n=33 plants arose from 2n=34 plants by fusion of two chromsomes. The plant with 2n=37 was intermediate in morphology betweenCarex conica (2n=36) andC. morrowii (2n=38) and probably originated as an interspecific hybrid between these species. 相似文献
18.
Domingo Ruvalcaba-Ruíz Guadalupe Palomino Javier Martínez Ignacio Méndez Benjamín Rodríguez-Garay 《In vitro cellular & developmental biology. Plant》2012,48(1):144-152
The effect of para-fluorophenylalanine (PFP) on the production of trisomic plants of Agave tequilana Weber var. Azul produced through somatic embryogenesis was investigated. Normal diploid plants with 2n = 2x = 60 were obtained in the control treatment and with 4 mg L−1 PFP exposure, while use of 8 and 12 mg L−1 PFP led to production of trisomics with 2n = 2x = 61. Normal diploid plants showed a bimodal karyotype with five pairs of large chromosomes and 25 pairs of small chromosomes.
Trisomic plants also had a bimodal karyotype with a group of three chromosomes in position five of the chromosome set. More
than 13 homologous chromosome pairs exhibited structural changes. Differences in chromosome arm ratio (long arm/short arm)
were also found in eight chromosome pairs; all these aberrations in the chromosome complement of trisomic plants were probably
caused by inversions, deletions, and/or duplications produced by high concentrations of PFP. The gross chromosome structural
changes and the presence of a single extra chromosome could have been induced by the effect of PFP on the mitotic spindle
by inducing nondisjunction of sister chromatids, resulting in hyperploids (2n + x) and hypoploids (2n − x). Flow cytometric analysis of nuclear DNA content was performed using nuclei isolated from young leaves of normal and trisomic
plants. The 2C DNA content of 8.635 pg (1Cx = 4,223 Mbp of trisomic plants was different (p < 0.001) than that of normal plants (2C DNA = 8.389 pg (1Cx = 4,102 Mbp). The difference in genome size was correlated with the large structural changes in the trisomic plant genomes. 相似文献
19.
Alien chromosome addition lines have been widely used for identifying gene linkage groups, assigning species-specific characters
to a particular chromosome and comparing gene synteny between related species. In plant breeding, their utilization lies in
introgressing characters of agronomic value. The present investigation reports the production of intergeneric somatic hybrids
Brassica
napus (2n = 38) + Orychophragmus violaceus (2n = 24) through asymmetric fusions of mesophyll protoplasts and subsequent development of B. napus-O. violaceous chromosome addition lines. Somatic hybrids showed variations in morphology and fertility and were mixoploids (2n = 51–67) with a range of 19–28 O. violaceus chromosomes identified by genomic in situ hybridization (GISH). After pollinated with B. napus parent and following embryo rescue, 20 BC1 plants were obtained from one hybrid. These exhibited typical serrated leaves of O. violaceus or B. napus-type leaves. All BC1 plants were partially male fertile but female sterile because of abnormal ovules. These were mixoploids (2n = 41–54) with 9–16 chromosomes from O. violaceus. BC2 plants showed segregations for female fertility, leaf shape and still some chromosome variation (2n = 39–43) with 2–5 O. violaceus chromosomes, but mainly containing the whole complement from B. napus. Among the selfed progenies of BC2 plants, monosomic addition lines (2n = 39, AACC + 1O) with or without the serrated leaves of O. violaceus or female sterility were established. The complete set of additions is expected from this investigation. In addition, O. violaceus plants at diploid and tetraploid levels with some variations in morphology and chromosome numbers were regenerated from the
pretreated protoplasts by iodoacetate and UV-irradiation.
Z. Zhao and T. Hu make equal contributions to this work. 相似文献
20.
The embryonic, larval and juvenile development of blue whiting,Sillago parvisquamis Gill, are described from a series of laboratory-reared specimens. Mean egg diameter and mean total length (TL) of newly-hatched
larvae were 0.71 mm and 1.58 mm, respectively. The eggs were non-adhesive, buoyant and spherical with an oil globule (mean
diameter 0.18 mm). Hatching occurred about 20 hours after fertilization at a temperature of 24.0–25.0°C, newly-hatched larvae
having 38–40 myomeres. The yolk and oil globule were completely absorbed 3 days after hatching at 2.8–3.2 (mean 3.0) mm TL.
Notochord flexion was completed by 7.2–8.2 (7.7) mm TL, and pectoral and caudal fin rays fully developed by approximately
10 mm and 8.5 mm TL, respectively. Completion of fin development occurred in the following sequence: caudal, pectoral, anal
and second dorsal, first dorsal and pelvic, the last-mentioned by approximately 11 mm TL. The larvae ofS. parvisquamis andS. japonica, which closely resemble each other in general morphology and pigmentation, could be distinguished as follows. Newly-hatchedS. parvisquamis larvae had more myomeres thanS. japonica (38–40 vs. 32–34) and more melanophores on the dorsal surface of the body (19–28 vs. about 40).Sillago japonica had a vertical band of melanophores on the caudal peduncle, which was lacking in postflexionS. parvisquamis larvae. In addition, juveniles ofS. parvisquamis (larger than 23 mm TL) had melanophores on the body extending anteriorly to below the lateral line to form a midlateral band,
whereas no obvious band occurred on similarly-sizedS. japonica juveniles. 相似文献