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1.
Karyotypes of three species of the subfamily Clupeinae collected from northern Japan were analyzed by in vitro methods and
their cellular DNA contents were measured using an integrating microdensitometer.Sardinella zunasi andSardinops melanostictus show very similar karyotypes: 2n = 48, consisting of acrocentric or subtelocentric chromosomes with a gradual decrease in
chromosome size, but with differences in cellular DNA of 2.32 and 2.69pg/cell respectively.Clupea pallasii differs from the aforementioned species in karyotype: 2n = 52, consisting of 6 metacentric or submetacentric chromosomes
and 46 acrocentric or subtelocentric chromosomes, with a cellular DNA content of 1.96 pg/cell. The results showed two different
modes in karyological evolution within the subfamily Clupeinae, i.e. an increase of cellular DNA content without apparent
change in karyotype, as shown bySardinella zunasi andSardinops melanostictus, and less change in cellular DNA content but with marked change in karyotype, as shown byClupea pallasii. 相似文献
2.
The subfamily Serrasalminae (Characidae, Teleostei) is an endemic Neotropical group of fishes distributed along the Amazon, Paraná‐Paraguay and Orinoco Basins. The pacu (Piaractus mesopotamicus) is found in all major rivers that comprise the Pantanal of Mato Grosso. In order to investigate population genetic structure within the group, an enriched microsatellite library was constructed. Eight polymorphic were loci screened, with an average of 6.5 alleles per locus. Five loci exhibited greater than 60% heterozygosity. Additionally, a high level of cross‐species amplification was obtained. 相似文献
3.
Invasion by Limnoperna fortunei (Dunker, 1857) (Bivalvia, Mytilidae) of the Pantanal Wetland, Brazil 总被引:1,自引:0,他引:1
Márcia Divina de Oliveira Alice M. Takeda Luciano Fernandes de Barros Domingos Sávio Barbosa Emiko Kawakami de Resende 《Biological invasions》2006,8(1):97-104
Limnoperna fortunei (Bivalvia, Mitylidae) was introduced into South America in 1991 in the La Plata River (Argentina). It arrived in the ballast water of ships coming
from Asia, where this species is native. It was first observed in 1998 in the Paraguay River. Limnoperna was introduced into the Pantanal region as hull fouling of vessels using the Paraguay–Parana waterway. This study describes
how L. fortunei came to the Pantanal region, and provides details of its occurrence, density, and impacts. From 1999 to 2002, observations
and sampling on natural and artificial substrates in the Paraguay River were made. Some aspects of the spread and impacts,
based on local community information, were also analyzed. On artificial substrate the density reached 523.8 individuals m−2 and on natural substrate (rocks), up to 10,000 individuals m−2 were found. The densities observed were quite low compared to those found in Southern Brazil, where values up to 100,000 individuals m−2 have been recorded in the last 3 years. In the Paraguay River, the population density of L. fortunei can be negatively impacted by periodic low levels of dissolved oxygen and decreases in pH to between 5 and 6. Such conditions
are frequently present during the periodic flooding or inundation of this area. Under these conditions, a high mortality of
L. fortunei was recorded in March of 2002, on both natural and artificial substrates. Despite low densities, L. fortunei can colonize water cooling systems of boats, obstructing water circulation and causing motor overheating. Accumulation in
water supply equipment, such as pumps and pipes has also been observed.
An erratum to this article is available at . 相似文献
4.
Characterization of sex chromosomes in rainbow trout and coho salmon using fluorescence in situ hybridization (FISH) 总被引:3,自引:0,他引:3
With the aim of characterizing the sex chromosomes of rainbow trout (Oncorhynchus mykiss) and to identify the sex chromosomes of coho salmon (O. kisutch), we used molecular markers OmyP9, 5S rDNA, and a growth hormone gene fragment (GH2), as FISH probes. Metaphase chromosomes were obtained from lymphocyte cultures from farm specimens of rainbow trout and coho salmon. Rainbow trout sex marker OmyP9 hybridizes on the sex chromosomes of rainbow trout, while in coho salmon, fluorescent signals were localized in the medial region of the long arm of one subtelocentric chromosome pair. This hybridization pattern together with the hybridization of a GH2 intron probe on a chromosome pair having the same morphology, suggests that a subtelocentric pair could be the sex chromosomes in this species. We confirm that in rainbow trout, one of the two loci for 5S rDNA genes is on the X chromosome. In males of this species that lack a heteromorphic sex pair (XX males), the 5S rDNA probe hybridized to both subtelocentrics This finding is discussed in relation to the hypothesis of intraspecific polymorphism of sex chromosomes in rainbow trout. 相似文献
5.
Despite the widespread distribution of Astyanax bockmanni in streams from Upper Paraná River system in central, southeastern, and southern Brazil, just recently, it has been identified
as a distinct Astyanax species. Cytogenetic studies were performed in two populations of this species, revealing conservative features. A. bockmanni shows 2n = 50 chromosomes, a karyotypic formula composed of 10 M + 12SM + 12ST + 16A and multiple Ag-NORs. Eight positive signals
in subtelocentric/acrocentric chromosomes were identified by fluorescent in situ hybridization (FISH) with 18S rDNA probes.
After FISH with 5S rDNA probes, four sites were detected, comprising the interstitial region of a metacentric pair and the
terminal region on long arms of another metracentric pair. Little amounts of constitutive heterochromatin were observed, mainly
distributed at distal region in two chromosomal pairs. Additionally, heterochromatin was also located close to the centromeres
in some chromosomes. No positive signals were detected in the chromosomes of A. bockmanni by FISH with the As-51 satellite DNA probe. The studied species combines a set of characteristics previously identified in
two different Astyanax groups. The chromosomal evolution in the genus Astyanax is discussed. 相似文献
6.
W. Vicentin F. E. dos S. Costa Y. R. Súarez 《Zeitschrift fur angewandte Ichthyologie》2012,28(1):143-145
Length–weight relationships (LWR) were estimated for 17 species and total length at first maturity (L50) for three species of freshwater fishes from the Miranda River, southern Pantanal, Brazil. The b values were compared for some species in the Paraguay River basin with the northern (Cuiabá River) part of the basin; differences in length–weight relationships were significantly different for Pseudoplatystoma corruscans, P. reticulatum (syn. P. fasciatum). First references on L50 and LWR are presented for two and eight fish species, respectively, as well as the new maximum total length for two species. 相似文献
7.
Genetic structure and evidence of anthropogenic effects on wild populations of two Neotropical catfishes: baselines for conservation 下载免费PDF全文
F. D. Do Prado R. Fernandez‐Cebrián F. Foresti C. Oliveira P. Martínez F. Porto‐Foresti 《Journal of fish biology》2018,92(1):55-72
Genetic diversity and structure of Pseudoplatystoma corruscans and P. reticulatum, large migratory South America catfishes, where overfishing and the construction of numerous dams in their feeding and reproducing areas are affecting their migratory processes negatively, were studied using microsatellites in samples from Paraguay (that comprises the Pantanal biome), and the upper and lower Paraná Basins. Genetic diversity was in accordance to that observed for other large migratory fishes, but the most geographically isolated populations of P. reticulatum and those P. corruscans subject to anthropogenic effects (stocking and dams) showed lower genetic diversity and evidences of bottlenecks compatible with low effective population size. Pseudoplatystoma reticulatum presented subtle genetic differentiation within the Paraguay area, especially between the edges of its distribution. Pseudoplatystoma corruscans, in this same area, presented a quite homogeneous but significant genetic break between the Paraguay and upper Paraná populations, apparently resulting from natural and historical isolation between the basins until recently. These data demonstrates that, although these Pseudoplatystoma spp. are abundant in the Pantanal area, anthropogenic events are leading to negative effects on their populations, particularly in the upper Paraná Basin. Genetic differentiation observed along each species distribution demands conservation actions to preserve each population's biodiversity. These results represent important genetic information using new microsatellite markers and the first genetic study of P. reticulatum covering this area of its native distribution. Data may also contribute to a better understanding of species migration patterns and to be used as a baseline for proper management. 相似文献
8.
Takashi Sugawara 《Journal of plant research》1982,95(3):295-302
The karyotype and the C-banding pattern in two species ofHexastylis andAsarum epigynum were analysed in detail, and the results obtained were compared with those of the other species ofAsarum, Asiasarum andHeterotropa previously reported.
The present results were partially different from the previous reports related to the karyotypes of these species. The karyotype
observed in two species ofHexastylis (2n=26) was represented by ten pairs of metacentric chromosomes and three pairs of small subtelocentric chromosomes, which
is very similar to that ofAsiasarum in eastern Asia. The C-banding patterns ofHexastylis andAsiasarum, however, were clearly different from each other. A striking difference was found in one of the three pairs of small subtelocentric
chromosomes. A Formosan speciesAsarum epigynum had the somatic chromosome number 2n=12 and a highly asymmetrical karyotype composed of mainly subtelocentric chromosomes.
These karyological features were remarkably different from those of the other groups inAsarum s.l. 相似文献
9.
J. D. Urdampilleta J. P. Coulleri M. S. Ferrucci E. R. Forni‐Martins 《Plant biology (Stuttgart, Germany)》2013,15(5):868-881
Cardiospermum L. belongs to the Paullinieae tribe (Sapindaceae) and comprises 16 species. Of these, 12 species are present in South America and all occur in Brazil. Cardiospermum shows the most variable chromosome number of the tribe. Phylogenetic relationships within the genus Cardiospermum, especially with other species of the tribe, are poorly understood. This research focuses on characterisation of the karyotypic features of Cardiospermum using conventional cytogenetic methods, CMA/DAPI chromosome banding and fluorescence in situ hybridisation (FISH). To elucidate the phylogeny of the genus, the nuclear markers ITS1 and ITS2 were sequenced and analysed using maximum parsimony and Bayesian inference. Cardiospermum shows important diversity in basic numbers, with x = 7, 9, 10, 11 and 12. All species studied have metacentric and submetacentric chromosomes, some species have subtelocentric chromosomes, while telocentric chromosomes are absent. The interphase nuclei differentiate the Cardiospermum species into two groups. The CMA3/DAPI chromosome banding revealed the presence of an AT‐rich terminal region in C. corindum, C. grandiflorum and C. urvilleoides, whereas GC‐rich regions were found in C. grandiflorum, C. halicacabum var. halicacabum, C. halicacabum var. microcarpum, C. heringeri and C. integerrimum. FISH revealed syntenic and non‐syntenic distribution of the 18‐5.8‐26S and 5S rDNA. The syntenic distribution always occurred in the short arms of the same chromosome in all of the species. The phylogenetic relationships reveal, in part, the taxonomic arrangement of the genus Cardiospermum. 相似文献
10.
Tsuda JR de Moraes VP Giuliano-Caetano L Dias AL 《Genetics and molecular research : GMR》2010,9(3):1929-1935
Five specimens of Rhamdia quelen collected from the Lindóia Stream, PR, Brazil, were cytogenetically analyzed. The diploid chromosome number found was 58, including 30 metacentric, 16 submetacentric, 10 subtelocentric, and 2 acrocentric chromosomes. Supernumerary or B chromosomes, frequently observed in this fish group, were not detected. One of the individuals was triploid, with 3n = 87. A silver-stained nucleolar organizer region was found on a pair of submetacentric chromosomes of the diploid specimens, and on three chromosomes of the triploid individual, confirming triploidy. Treatment with fluorochrome chromomycin A(3) revealed fluorescent bands coincident with those of the silver-stained nucleolar organizer region, in both diploid and triploid individuals, showing that this is a GC-rich region. Heterochromatin distribution was visualized by the C-banding technique, mainly in the terminal chromosome regions of the individuals and was also observed in the pericentromeric regions of some chromosomes and at both telomeres. 相似文献
11.
Fábio Hiroshi Takagui Natalia Bortolazzi Venturelli Tatiane Ramos Sampaio Ana Lúcia Dias Lúcia Giuliano-Caetano 《Ichthyological Research》2014,61(3):201-206
Cytogenetic analyses were performed on Corydoras britskii from the Miranda River basin, an important river located in the Pantanal, Mato Grosso do Sul State, Brazil. The karyotype of this species comprises 90 chromosomes and a karyotype formula of 4m + 10 sm + 22 st + 54a. The nucleolus organizer regions were detected by impregnation with silver nitrate and FISH with an 18S rDNA probe on the short arm of three acrocentric chromosomes. The constitutive heterochromatin is distributed in pericentromeric and interstitial positions, and also associated with the NORs. The HinfI restriction endonuclease was used and showed homology with practically all types of heterochromatin observed in C. britskii, except for two interstitial heterochromatic blocks present in a subtelocentric pair. The fluorochrome staining evidenced six chromosomes with chromomycin-positive signals indicating that both the heterochromatin interspersed with NORs and some heterochromatic blocks were rich in GC base pairs. FISH using a 5S rDNA probe revealed the presence of these regions in only one subtelocentric pair in the interstitial position. The obtained data substantiate the karyotype diversity of the genus Corydoras and provide novel information about the composition of heterochromatin and location of 5S and 18S rDNA sites. 相似文献
12.
The karotype of Saguinus midas niger was studied by G-, C-, and nuclear organizer region (NOR)-banding techniques. Variations in C-banding patterns were observed in some chromosomes. The banding patterns obtained were compared with those previously described for Callithrix jacchus. The two species differ by a reciprocal translocation involving pairs 9 and 16; by a paracentric inversion in chromosomes 1, 13, 14, 18, and 22; and by a pericentric inversion in at least four subtelocentric pairs (chromosomes 19, 20, 21, and 22), dislocating the nucleolar organizer region from the small short arm in C. jacchus to the proximal segment of the long arm in S. m. niger (or vice versa). The amount of constitutive heterochromatin is greater in S. m. niger than in C. jacchus, especially in chromosomes 4, 7, and 14. The Y chromosome is smaller in C. jacchus than in S. m. niger. 相似文献
13.
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
14.
Karyotype and other chromosomal markers of Characidium cf. gomesi were analyzed using conventional (Giemsa-staining, Ag-NOR and C-banding) and molecular (Fluorescent in situ hybridization
(FISH) with 18S and 5S rDNA biotinylated probes) techniques. Both sexes had invariably diploid chromosome number 2n = 50 while
karyotypes of males and females differed. That of male consisted of 32 metacentric + 18 submetacentric chromosomes and that
of female consisted 31 metacentric + 18 submetacentric + 1 subtelocentric chromosomes. The Z chromosome was medium-sized metacentric,
while W was highly heterochromatinized subtelocentric element. NORs as revealed by Ag-staining were situated at 2–7 telomeric
regions while FISH with 18S probes showed consistently 10 signals at telomeric regions. FISH with 5S rDNA probe showed constantly
signals at one metacentric pair. Distribution of centromeric heterochromatin was mostly in all chromosome pairs, besides some
telomeric sites. The common origin of the sex chromosome system of ZZ/ZW type in the karyotypes of other representatives of
the genus analyzed so far might be hypothesized based on biogeography and partial phylogeny of the group. 相似文献
15.
The parthenogenetic Marmorkrebs (Malacostraca: Decapoda: Cambaridae) is a triploid organism 下载免费PDF全文
Peer Martin Sven Thonagel Gerhard Scholtz 《Journal of Zoological Systematics and Evolutionary Research》2016,54(1):13-21
There is a close association between parthenogenesis and polyploidy. For this reason, we undertook a karyological analysis to test whether the parthenogenetic Marmorkrebs, Procambarus fallax forma virginalis, possesses an enlarged set of chromosomes. For this purpose, we karyotyped the Marmorkrebs, the sexual form of P. fallax (together called P. fallax complex), and the closely related species P. alleni. The latter shows 94 chromosomes in the haploid condition. In contrast to this, we found a haploid set of 92 chromosomes in individuals of the P. fallax complex. However, in mitotic metaphases the sexual form shows 184 chromosomes, whereas the Marmorkrebs possesses 276 chromosomes. Hence, the parthenogenetic Marmorkrebs reveals a triple amount of the haploid chromosome number. In addition, we detected a strikingly large subtelocentric chromosome which appears once in haploid and twice in diploid cells of sexual individuals of the P. fallax complex. In the parthenogenetic Marmorkrebs, this prominent chromosome occurs thrice. All this clearly reveals that the Marmorkrebs is a triploid organism. The applicability of the used methods, the significance of polyploidy in evolution of Decapoda, putative pathways to parthenogenetic triploidy, a possible hybrid origin and the scientific and ecological consequences of an increased chromosome set in Marmorkrebs are discussed. 相似文献
16.
Mamta Singh Ravindra Kumar N. S. Nagpure B. Kushwaha Indramani Gond W. S. Lakra 《Genetica》2009,137(3):245-252
Dual color fluorescence in situ hybridization (FISH) was performed to study the simultaneous chromosomal localization of 18S
and 5S ribosomal genes in the genus Tor for the first time. The 18S and 5S rDNAs in four Tor species were amplified, sequenced and mapped on the metaphase chromosomes. The number and distribution of 18S and 5S rDNA
clusters were examined on metaphase chromosome spreads using FISH. The specimens of T. chelynoides, T. putitora and T. progeneius showed six bright fluorescent signals of 18S rDNA and T. tor exhibited ten such signals. The 5S rDNA signals were present only on one pair of chromosomes in all the four Tor species. Ag-NORs were observed on two pairs of chromosomes in T. chelynoides, T.
putitora, T. progeneius and four pairs in T. tor. Comparison of the observed 18S rDNA FISH signals and Ag-NORs strongly suggested a possible inactivation of NORs localized
at the telomeres of a subtelocentric and telocentric chromosome pairs in all four species. The 5S rDNA contained an identical
120 bp long coding region and 81 bp long highly divergent non-transcribed spacers in all species examined. 18S and 5S rDNA
sequencing and chromosomal localization can be a useful genetic marker in species identification as well as phylogenetic and
evolutionary studies. 相似文献
17.
18.
das Neves AC Pieczarka JC Barros RM Marques-Aguiar S Rodrigues LR Nagamachi CY 《Cytobios》2001,105(409):91-98
The Choeroniscus genus (Glossophaginae, Phyllostomidae) has five monotypic species: C. minor, C. godmani, C. intermedius, C. inca and C. periosus. This paper analyses the karyotype of a female C. minor, collected close to the Guama river (Belém, Para, Brazil). G-, C-banding and NOR-staining were performed. This species has 2n = 20 chromosomes, where there are two bi-armed pairs (numbers 1 and 9) and seven subtelocentric pairs (2, 3, 4, 5, 6, 7 and 8). The probable X chromosome is a submetacentric. The constitutive heterochromatin can be found in the short arm of five subtelocentric pairs (4, 5, 6, 7 and 8) and is centromeric in the bi-armed pairs numbers 1 and 9, and the X chromosome. The heterochromatic bands are heteromorphic in three pairs (1, 2 and 3). Active NOR were observed in the short arms of eight subtelocentric chromosomes, suggesting that at least four pairs are nucleolar organizers. This paper describes for the first time the karyotype of C. minor from the Amazon region. 相似文献
19.
do Prado FD Nunes TL Senhorini JA Bortolozzi J Foresti F Porto-Foresti F 《Genetics and molecular biology》2012,35(1):57-64
The cytogenetic characteristics of Pseudoplatystoma corruscans and Pseudoplatystoma reticulatum and their F1, F2 and backcross hybrids were assessed by using chromosome banding techniques. The diploid number of 56 chromosomes was constant in all species and lineages, with a karyotypic formula containing 20 metacentric, 12 submetacentric, 12 subtelocentric and 12 acrocentric chromosomes. Nucleolar organizer regions (NORs) were identified in two subtelocentric chromosomes in the parents and hybrids, with partial nucleolar dominance in F1 and F2 specimens. Heterochromatic blocks were detected in the terminal and centromeric regions of some chromosomes in all individuals. For parental and hybrid lineages, 18S ribosomal clusters corresponding to NORs and 5S ribosomal genes were identified in distinct pairs of chromosomes. The striking conservation in the chromosomal macrostructure of the parental species may account for the fertility of their F1 hybrids. Similarly, the lack of marked alterations in the chromosomal structure of the F1 hybrids could account for the maintenance of these features in post-F1 lineages. 相似文献
20.
A chromosome 1 (Cr1) pericentric inversion is described in six of seven species in the genus Ctenomys (tuco-tucos) from Uruguay. The inversion was inferred from G-band analyses of subtelocentric Cr1 hypothesised to be derived
from the ancestral metacentric condition. Cr1 varies across species in heterochromatin amount and localisation including a
metacentric chromosome without positive C-bands in C. torquatus, a subtelocentric chromosome with heterochromatic short arms in C. rionegrensis, and a subtelocentric chromosome negative after C-banding in five of the species analysed here. Pachytene chromosomes from
C. rionegrensis, a species with the highest heterochromatin content, and C. torquatus, one of the species with the lowest heterochromatin content, were analysed in order to assess possible mechanisms of heterochromatin
evolution. This analysis revealed the presence of three heterochromatic chromocenters in C. rionegrensis where bivalents converge, while in C. torquatus only one chromocenter was observed. In both species, highly repetitive DNA was observed, localised in chromocenters after
“in situ” hybridisation. Heterochromatin associated protein M31 was localised in chromocenters of both species after immuno-detection.
The spread of heterochromatin in Ctenomys chromosomes could be produced by chromatin exchanges at the chromocenter level. We propose the exchange of this DNA associated
proteins between non-homologous chromosomes in pachytene to be the responsible for the spread of heterochromatin through the
karyotypes of species like C. rionegrensis 相似文献