Download Consulta: subjectFacets:"5S rDNA" Registros recuperados: 16 Data

Consulta: subjectFacets:"5S rDNA"
Registros recuperados: 16
Data/hora: 09/06/2017 05:35:57
Chromosome mapping of 5S rRNA genes differentiates Brazilian populations of Leporellus vittatus
(Anostomidae, Characiformes)
Provedor de dados: 74
Autores: Aguilar,Cecilia Teixeira de; Galetti Junior,Pedro Manoel.
Among the anostomid fishes, the genus Leporellus is represented by only three species: L. nattereri, endemic of the Amazon
River, L. retropinnis, endemic of the Piracicaba River, and L. vittatus, widely distributed in rivers from Peru, Colombia, Guianas,
and different major hydrographic basins of Brazil. A cytogenetic study carried out on specimens of Leporellus vittatus from three
major Brazilian hydrographic basins evidenced a karyotype of 54 metacentric and submetacentric chromosomes. C-banding
analysis revealed the presence of large pericentromeric heterochromatic segments in all chromosomes and a telomeric block
coincident with the NOR sites. Ag, CMA3 or MM staining, and FISH with ribosomal probes located the 45S ribosomal genes on
the terminal region...
Tipo: Journal article
Palavras-chave: Karyotype; C-bands; 45S rDNA; 5S rDNA.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200004
5S rDNA characterization in twelve Sciaenidae fish species (Teleostei, Perciformes): depicting gene
diversity and molecular markers
Provedor de dados: 74
Autores: Alves-Costa,Fernanda A.; Martins,Cesar; Matos,Fernanda Del Campos de; Foresti,Fausto; Oliveira,Claudio;
Wasko,Adriane P.
In order to extend the genetic data on the Sciaenidae fish family, the present study had the purpose to characterize PCR-generated
5S rDNA repeats of twelve species of this group through PAGE (Polyacrylamide Gel Electrophoresis) analysis. The results
showed the occurrence of at least two different 5S rDNA size classes in all the species. Moreover, 5S rDNA repeats of one of the
studied species - Isopisthus parvipinnis - were cloned and subjected to nucleotide sequencing and Southern blot membrane
hybridization analyses, which permitted to confirm the existence of two major 5S rDNA classes. Phylogenetic analysis based on
the nucleotide sequences of different 5S rDNA repeats of I. parvipinnis lead to their separation into two major clusters. These
results may...
Tipo: Journal article
Palavras-chave: Sciaenidae; Fish; Isopisthus parvipinnis; 5S rDNA; Molecular markers.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200025
Allopatric chromosomal variation in Nematocharax venustus Weitzman, Menezes &
Britski, 1986 (Actinopterygii: Characiformes) based on mapping of repetitive sequences
Provedor de dados: 83
Autores: Barreto,Silvia B.; Cioffi,Marcelo B.; Medrado,Aline S.; Silva,André T.; Affonso,Paulo R. A. M.; Diniz,Débora.
ABSTRACT Characiformes is the most cytogenetically studied group of freshwater Actinopterygii, but karyotypical data of
several taxa remain unknown. This is the case of Nematocharax , regarded as a monotypic genus and characterized by marked
sexual dimorphism. Therefore, we provide the first cytogenetic report of allopatric populations of Nematocharax venustus based
on distinct methods of chromosomal banding and fluorescence in situ hybridization (FISH) with repetitive DNA probes (18S and
5S rDNA). The karyotype macrostructure was conserved in all specimens and populations, independently on sex, since they
shared a diploid number (2n) of 50 chromosomes divided into 8m+26sm+14st+2a. The heterochromatin was mainly distributed at
pericentromeric regions and...
Tipo: Journal article
Palavras-chave: 18S rDNA; 5S rDNA; Coastal drainages; FISH; Population cytogenetics.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252016000200205
Cytotaxonomy of Parodon nasus and Parodon tortuosus (Pisces, Characiformes): A case of synonymy
confirmed by cytogenetic analyses
Provedor de dados: 74
Autores: Bellafronte,Elisangela; Margarido,Vladimir Pavan; Moreira-Filho,Orlando.
Morphological and cytogenetical studies were carried out on the freshwater fish Parodon nasus and Parodon tortuosus in order to
evaluate a putative synonymy. The diploid chromosome number observed in both species was 2n = 54 (48M/SM and 6ST) with
no differences between the sexes. Despite slight differences in the pattern of heterochromatin distribution and the number of cusps
in symphysean teeth, the location of nucleolar organizer regions (NORs) and 5S rRNA genes (both species-specific features) were
similar in both species. The remarkable similarity observed between these allopatric species supports recent taxonomical reviews
indicating that P. tortuosus is a synonym for P. nasus.
Tipo: Journal article
Palavras-chave: Cytogenetics; Parodontidae; Systematics; 18S rDNA; 5S rDNA.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000500010
Sex chromosome system ZZ/ZW in Apareiodon hasemani Eigenmann, 1916 (Characiformes,
Parodontidae) and a derived chromosomal region
Provedor de dados: 74
Autores: Bellafronte,Elisangela; Schemberger,Michelle Orane; Artoni,Roberto Ferreira; Moreira Filho,Orlando; Vicari,Marcelo
Ricardo.
Parodontidae fish show few morphological characteristics for the identification of their representatives and chromosomal analyses
have provided reliable features for determining the interrelationships in this family. In this study, the chromosomes of Apareiodon
hasemani from the São Francisco River basin, Brazil, were analyzed and showed a karyotype with 2n = 54 meta/submetacentric
chromosomes, and a ZZ/ZW sex chromosome system. The study revealed active NORs located on pair 11 and additional 18S
rDNA sites on pairs 7 and 22. The 5S rDNA locus was found in pair 14. It showed a pericentric inversion regarding the ancestral
condition. The satellite DNA pPh2004 was absent in the chromosomes of A. hasemani, a shared condition with most members of
Apareiodon....
Tipo: Journal article
Palavras-chave: Cytogenetics; FISH; 18S rDNA; 5S rDNA; Neotropical fishes.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572012000500010
Mapping of the 18S and 5S ribosomal RNA genes in Astyanax altiparanae Garutti &
Britski, 2000 (Teleostei, Characidae) from the upper Paraná river basin, Brazil
Provedor de dados: 74
Autores: Fernandes,Carlos Alexandre; Martins-Santos,Isabel Cristina.
Fluorescence in situ hybridization (FISH) was undertaken in order to determinate the chromosomal distribution pattern of 18S and
5S ribosomal DNAs (rDNA) in four populations of the characid fish Astyanax altiparanae from the upper Paraná river basin,
Brazil. The 18S rDNA probe FISH revealed numerical and positional variations among specimens from the Keçaba stream
compared to specimens of the other populations studied. In contrast to the variable 18S rDNA distribution pattern, highly stable
chromosomal positioning of the 5S rDNA sites was observed in the four A. altiparanae populations. Divergence in the distribution
pattern of 18S and 5S rDNA sites is also discussed.
Tipo: Journal article
Palavras-chave: Astyanax altiparanae; Fluorescence in situ hybridization (FISH); 18S rDNA; 5S rDNA; Sequential Ag-NOR.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572006000300011
Localization of ribosomal genes in three Pimelodus species (Siluriformes, Pimelodidae) of the São
Francisco River: 5S genes as species markers and conservation of the 18S rDNA sites
Provedor de dados: 74
Autores: Garcia,Caroline; Moreira Filho,Orlando.
Pimelodidae is one of the most representative of Neotropical catfish families. However, these fish are still poorly studied in terms
of cytogenetics, especially regarding the application of more accurate techniques such as the chromosomal localization of
ribosomal genes. In the present work, fluorescent in situ hybridization with 5S and 18S rDNA probes was employed for rDNA site
mapping in Pimelodus sp., P. fur and P. maculatus from the São Francisco River in the Três Marias municipality - MG. The
results from the application of the 18S probe confirmed the previous data obtained by silver nitrate staining, identifying a simple
nucleolar organizing region system for these species. However, the labeling results from the 5S rDNA probe demonstrated a...
Tipo: Journal article
Palavras-chave: Pimelodus; Paracentric inversion; 5S rDNA; 18S rDNA; Species marker.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200018
Karyotype characterization of Mugil incilis Hancock, 1830 (Mugiliformes: Mugilidae), including a
description of an unusual co-localization of major and minor ribosomal genes in the family
Provedor de dados: 83
Autores: Hett,Anne Kathrin; Nirchio,Mauro; Oliveira,Claudio; Siccha,Zoila Raquel; Rossi,Anna Rita; Sola,Luciana.
This study reports the description of the karyotype of Mugil incilis from Venezuela. The chromosome complement is composed of
48 acrocentric chromosomes, which uniformly decrease in size. Therefore, the homologues can not be clearly identified, with the
exception of one of the largest chromosome pairs, classified as number 1, whose homologues may show a subcentromeric
secondary constriction, and of chromosome pair number 24, which is considerably smaller than the others. C-banding showed
heterochromatic blocks at the centromeric/pericentromeric regions of all chromosomes, which were more conspicuous on
chromosomes 1, given the C-positive signals include the secondary constrictions. AgNO3 and fluorescent in situ hybridization
(FISH) with 45S rDNA...
Tipo: Journal article
Palavras-chave: C-banding; COI; 5S rDNA; Mullet; NORs.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252011000100008
Morphological characterization under different ecological habitats and physical mapping of 5S and
45S rDNA in Lilium distichum with fluorescence in situ hybridization
Provedor de dados: 97
Autores: Hwang,Yoon-Jung; Song,Chang-Min; Younis,Adnan; Kim,Chang-Kil; Kang,Yoon-Im; Lim,Ki-Byung.
BACKGROUND: This study was performed to investigate the phenotypic, karyomorphological, and habitat environment
characteristics of Lilium distichum that grows naturally in South Korea. Currently, this species follows limited distribution areas
and its natural populations are at the brink of extinction mainly due to fragmentation or destruction its natural habitat. RESULTS:
This species was distributed between approximately 1,000 and 1,500 m above sea level with an average temperature of 22°C. The
soil characteristics surrounding the natural habitats included loamy and silt loam soils having organic matter content (10.82%), pH
(5.22), electrical conductivity (EC) (0.37 dS/m), total nitrogen (0.45%), and cation exchange capacity (34.3 cmol+/kg). The
peak...
Tipo: Journal article
Palavras-chave: Chromosome; Karyotype; Habitat; Korea; 5S rDNA; 45S rDNA.
Ano: 2015
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2015000100008
B chromosome and NORs polymorphism in Callichthys callichthys (Linnaeus, 1758) (Siluriformes:
Callichthyidae) from upper Paraná River, Brazil
Provedor de dados: 83
Autores: Konerat,Jocicléia Thums; Bueno,Vanessa; Baumgartner,Lucas; Martins-Santos,Isabel Cristina; Margarido,Vladimir
Pavan.
B chromosomes are extra chromosomes from the normal chromosomal set, found in different organisms, highlighting their
presence on the group of fishes. Callichthys callichthys from the upper Paraná River has a diploid number of 56 chromosomes (26
m-sm + 30 st-a) for both sexes, with the presence of a sporadically acrocentric B chromosome. Moreover, one individual
presented a diploid number of 57 chromosomes, with the presence of a morphologically ill-defined acrocentric B chromosome in
all analyzed cells. The physical mapping of 5S and 18S rDNA shows multiple 5S rDNA sites and only one pair of chromosomes
with 18S sites in C. callichthys, except for two individuals. These two individuals presented a third chromosome bearing NORs
(Ag-staining and 18S rDNA)...
Tipo: Journal article
Palavras-chave: 18S rDNA; 5S rDNA; Chromosomal rearrangements; FISH; Supernumerary chromosome.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252014000300603
Robertsonian rearrangements in the reef fish Chromis (Perciformes, Pomacentridae) involving
chromosomes bearing 5s rRNA genes
Provedor de dados: 74
Autores: Molina,Wagner F.; Galetti-Jr,Pedro M.
Cytogenetic studies were done on three Pomacentridae species of the genus Chromis. The karyotype of C. multilineata consisted
of 48 acrocentric chromosomes (FN = 48), C. insolata had 2n = 46-47 (3-4M+6SM+36-38A; FN = 56) and C. flavicauda had 2n =
39 (9M+6SM+24A; FN = 54). Robertsonian polymorphisms were detected in C. insolata and C. flavicauda. All three species had
small heterochromatic blocks restricted to centromeric regions. Nucleolar organizer regions (NORs) were detected in the
telomeric position of a medium acrocentric chromosome pair in C. multilineata and in non-homologous chromosomes in both C.
flavicauda and C. insolata. FISH with a telomeric probe detected no internal telomeric sequences in C. flavicauda and C. insolata.
5S rRNA genes were...
Tipo: Journal article
Palavras-chave: Chromis; FISH; Polymorphism; Robertsonian rearrangements; 5S rDNA; Telomeric sequences.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572002000400004
Karyotypic conservatism in samples of Characidium cf. zebra (Teleostei, Characiformes,
Crenuchidae): physical mapping of ribosomal genes and natural triploidy
Provedor de dados: 74
Autores: Pansonato-Alves,José Carlos; Oliveira,Claudio; Foresti,Fausto.
Basic and molecular cytogenetic analyses were performed in specimens of Characidium cf. zebra from five collection sites located
throughout the Tietê, Paranapanema and Paraguay river basins. The diploid number in specimens from all samples was 2n = 50
with a karyotype composed of 32 metacentric and 18 submetacentric chromosomes in both males and females. Constitutive
heterochromatin was present at the centromeric regions of all chromosomes and pair 23, had additional interstitial heterochromatic
blocks on its long arms. The nucleolar organizer regions (NORs) were located on the long arms of pair 23, while the 5S rDNA
sites were detected in different chromosomes among the studied samples. One specimen from the Alambari river was a natural
triploid and had...
Tipo: Journal article
Palavras-chave: Characidium; Heterochromatin; 18S rDNA; 5S rDNA; Natural triploidy.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572011000200007
Cytogenetic and molecular markers reveal the complexity of the genus Piabina Reinhardt, 1867
(Characiformes: Characidae)
Provedor de dados: 83
Autores: Pazian,Marlon Felix; Pereira,Luiz Henrique Garcia; Shimabukuru-Dias,Cristiane Kioko; Oliveira,Claudio;
Foresti,Fausto.
Cytogenetic and molecular analyses were carried out in fish representative of the genus Piabina. This study specifically involved
the species P. argentea and P. anhembi collected from areas of the Paranapanema and Tietê River basins, Brazil. Our findings
suggest that fish classified as Piabina argentea in the Paranapanema and Tietê Rivers may represent more than one species. The
samples analyzed differed by cytogenetic particularities and molecular analyses using partial sequences of the genes COI and
CytB as genetic markers revealed three distinct groups of P. argentea with genetic distances sufficient to support the conclusion
that the three samples analyzed are three distinct taxonomic units.
Tipo: Journal article
Palavras-chave: DNA Barcoding; Freshwater fishes; Fish; MtDNA; 18S rDNA; 5S rDNA.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252012000200008
Discrimination of Shark species by simple PCR of 5S rDNA repeats
Provedor de dados: 74
Autores: Pinhal,Danillo; Gadig,Otto BF; Wasko,Adriane P; Oliveira,Claudio; Ron,Ernesto; Foresti,Fausto; Martins,Cesar.
Sharks are suffering from intensive exploitation by worldwide fisheries leading to a severe decline in several populations in the
last decades. The lack of biological data on a species-specific basis, associated with a k-strategist life history make it difficult to
correctly manage and conserve these animals. The aim of the present study was to develop a DNA-based procedure to
discriminate shark species by means of a rapid, low cost and easily applicable PCR analysis based on 5S rDNA repeat units
amplification, in order to contribute conservation management of these animals. The generated agarose electrophoresis band
patterns allowed to unequivocally distinguish eight shark species. The data showed for the first time that a simple PCR is able to...
Tipo: Journal article
Palavras-chave: Chondrichthyes; PCR; Species identification; 5S rDNA; Sharks.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200033
Chromosome mapping of repetitive sequences in four Serrasalmidae species (Characiformes)
Provedor de dados: 74
Autores: Ribeiro,Leila Braga; Matoso,Daniele Aparecida; Feldberg,Eliana.
The Serrasalmidae family is composed of a number of commercially interesting species, mainly in the Amazon region where most
of these fishes occur. In the present study, we investigated the genomic organization of the 18S and 5S rDNA and telomeric
sequences in mitotic chromosomes of four species from the basal clade of the Serrasalmidae family: Colossoma macropomum,
Mylossoma aureum, M. duriventre, and Piaractus mesopotamicus, in order to understand the chromosomal evolution in the
family. All the species studied had diploid numbers 2n = 54 and exclusively biarmed chromosomes, but variations of the
karyotypic formulas were observed. C-banding resulted in similar patterns among the analyzed species, with heterochromatic
blocks mainly present in centromeric...
Tipo: Journal article
Palavras-chave: 5S rDNA; Telomeric sequences; Tambaqui and pacu.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572014000100009
Nucleotide sequence, genomic organization and chromosome localization of 5S rDNA in two species of
Curimatidae (Teleostei, Characiformes)
Provedor de dados: 74
Autores: Santos,Lessandra Viviane de Rosa; Foresti,Fausto; Wasko,Adriane Pinto; Oliveira,Claudio; Martins,Cesar.
The 5S ribosomal DNA (5S rDNA) of higher eukaryotes is organized in repeat units of tandem arrays composed of a 5S rDNA
coding region, conserved even among non-related taxa, and a variable non-transcribed spacer sequence (NTS). To contribute to
knowledge on the organization and evolution of vertebrate 5S rDNA we used PCR, nucleotide sequencing, Southern blot
hybridization and chromosome fluorescence in situ hybridization (FISH) to investigate 5S rDNA tandem repeats in the South
American Curimatidae fish Steindachnerina insculpta and Cyphocharax modesta. 5S rDNA repeats of 180 base pairs (bp) from
both species were PCR-generated and sequenced evidencing the shortest 5S rDNA monomer so far described in eukaryote
species. Southern blotting revealed that both...
Tipo: Journal article
Palavras-chave: Cyphocharax modesta; Steindachnerina insculpta; 5S rDNA; Chromosomes; FISH; Nucleotide sequence.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572006000200009