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B chromosome and NORs polymorphism in Callichthys callichthys (Linnaeus, 1758) (Siluriformes: Callichthyidae) from upper Paraná River, Brazil Neotropical Ichthyology
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: Info:eu-repo/semantics/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
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Comparative Cytogenetics Among Three Sympatric Hypostomus Species (Siluriformes: Loricariidae): An Evolutionary Analysis in a High Endemic Region BABT
Lorscheider,Carla Andreia; Oliveira,Jordana Inácio Nascimento; Dulz,Thais Aparecida; Nogaroto,Viviane; Martins-Santos,Isabel Cristina; Vicari,Marcelo Ricardo.
ABSTRACT The karyotypes of three armored catfish species (Loricariidae) from the Iguaçu river, southern of the Brazil, were compared using different techniques: C-banding, Ag-NOR and fluorescence in situ hybridization (FISH), which used 5S and 18S rDNAs and total Cot-1 fraction as probes. Hypostomus commersoni and Hypostomus derbyi presented 2n = 68 chromosomes, with karyotype formulae 12m+12sm+14st+30a and 12m+12sm+10st+34a, respectively; whereas Hypostomus myersi presented 2n = 74 chromosomes and 12m+16sm+12st+34a. The chromosomal localization of the Ag-NORs, 5S and 18S rDNAs differed in number of sites and chromosomal localization among the studied species. The total Cot-1 probe permitted the visualization of the repetitive DNA fraction in karyotypes of...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Armored catfish; FISH; Iguaçu river; Karyotype evolution.
Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132018000100435
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Cytogenetic analysis of Astyanax laticeps (Cope, 1894) (Ostariophysi: Characidae) from the laguna dos Patos system Neotropical Ichthyology
Rosa,Renata da; Rubert,Marceléia; Malabarba,Luiz R.; Martins-Santos,Isabel Cristina; Giuliano-Caetano,Lucia.
The genus Astyanax is prominent among Characiformes, due to the large number of species found and its wide geographic distribution. In this work, Astyanax laticeps specimens from the laguna dos Patos system were cytogenetically analyzed. A diploid number of 2n = 50 chromosomes distributed into 6m+16sm+16st+12a (FN = 88) was found, without differences between males and females. A few small heterochromatin blocks were observed, besides three more conspicuous C-bands, corresponding to NORs, as confirmed by silver nitrate and CMA3 staining, FISH, and DAPI negative staining. These regions were located in a medium-sized subtelocentric and in a large subtelocentric chromosomal pair, probably because of a deletion of this region in one homologous chromosome, or...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Astyanax scabripinnis species complex; RDNA; Homologous transposition.
Ano: 2009 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252009000400007
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Cytogenetic and morphometric differences in populations of Astyanax "scabripinnis" (Pisces, Characidae) from Maringá region, PR, Brazil Genet. Mol. Biol.
Mizoguchi,Sônia Maria Hiromi Nakagawa; Martins-Santos,Isabel Cristina.
A cytogenetic and morphometric study of four populations of characid fish assigned to the "complex" of Astyanax scabripinnis originating from three riverine basins, namely Ivaí (populations A and B), Paranapanema (C) and Paraná (D), was carried out. Karyological analysis showed the diploid chromosome number 2n = 48 for population B and 2n = 50 for the remaining populations. All populations under study differed in the composition of karyotypes and C-banding patterns. Canonical variable analysis used to assess the morphometric data revealed that 1) the four populations under study were entirely discriminated from each other and 2) the coefficients that most contributed to this pattern were standard length, rostrodorsal distance, eye diameter and snout...
Tipo: Info:eu-repo/semantics/article
Ano: 1998 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571998000100010
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Intra-individual numerical chromosomal polymorphism in Trichomycterus davisi (Siluriformes, Trichomycteridae) from the Iguaçu River basin in Brazil Genet. Mol. Biol.
Borin,Luciana Andreia; Martins-Santos,Isabel Cristina.
Cytogenetic analysis of Trichomycterus davisi, collected from the Iguaçu River basin, has shown a diploid number of 2n = 54 chromosomes. However, we observed intra-individual numerical polymorphism in a T. davisi specimen. There were three cell populations with diploid number 2n = 54 (40M + 12SM + 2ST), 2n = 55 (40M + 12SM + 2ST + 1M) and 2n = 56 (40M + 12SM + 2ST + 2A) chromosomes. This variation was attributed to a probable post-zygotic non-disjunction of a metacentric chromosome of small/middle size, followed by centric fission, which originated in this individual.
Tipo: Info:eu-repo/semantics/other
Ano: 2000 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000300018
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Mapping of the 18S and 5S ribosomal RNA genes in Astyanax altiparanae Garutti & Britski, 2000 (Teleostei, Characidae) from the upper Paraná river basin, Brazil Genet. Mol. Biol.
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: Info:eu-repo/semantics/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
Registros recuperados: 6
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