Karyotypic Diversity in a Bryconamericus aff. exodon Population(Characidae, Tetragonopterinae).

Paintner-Marques, Tânia Regina; Giuliano-Caetano, Lúcia; Dias, Ana Lúcia

doi:10.1508/cytologia.67.397

Cited by 12 publications

(12 citation statements)

References 11 publications

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“…Maistro et al (2000) analyzing specimens of Astyanax scabripinnis from the Tamanduá stream, State of São Paulo, Brazil, observed specimens with 2nϭ50 and 2nϭ48 chromosomes, also with differences in the chromosome morphology. Paintner-Marques et al (2002) observed the presence of 2 cytotypes on specimens of Bryconamericus aff. exodon from Três Bocas stream, Paraná State, Brazil, where the examples not differentiated taxonomically presented clear differences in the chromosome morphology.…”

Section: Discussionmentioning

confidence: 99%

Cytogenetic Analysis of Three Sympatric Gymnotus Species (Teleostei: Gymnotidae) from the Fundo Stream, MG, Brazil

Lacerda

Maistro

2007

CYTOLOGIA

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Summary Three sympatric species of Gymnotus from the Fundo stream, a small tributary of the Sapucaí river, Minas Gerais State, Brazil, were studied in relation to their karyology. Gymnotus sylvius presented 2nϭ40 chromosomes (36 m/smϩ4 st/a), Gymnotus sp. presented 2nϭ50 (26 m/smϩ 24 st/a) and Gymnotus paraguensis had 2nϭ54 (50 m/smϩ4 st/a). C-banding demonstrated positively stained heterochromatic blocks in the centromeric position of few chromosomes on G. sylvius and in the centromeric region of all chromosomes on G. paraguensis samples. The nucleolus organizer region (NOR) was located on the short arm of one st chromosome pair in G. sylvius and Gymnotus sp., and in the interstitial position on the short arm of the pair number one and below the centromere on a third chromosome on G. paraguensis. The cytogenetic data obtained indicate that Gymnotus sp. represent a new Gymnotus specie with a karyotypic constitution never observed on others species from this genus. Some aspects related to the chromosome diversification of these Gymnotus are discussed.

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Section: Discussionmentioning

confidence: 99%

Cytogenetic Analysis of Three Sympatric Gymnotus Species (Teleostei: Gymnotidae) from the Fundo Stream, MG, Brazil

Lacerda

Maistro

2007

CYTOLOGIA

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“…The three karyotype formulae obtained in the present study and the karyotype reported by Paintner-Marques et al (2003) suggest the occurrence of fixed extensive evolutionary chromosome diversification in this species. The fundamental number in this genus ranges from 84 to 102 (Portela et al, 1988;Wasko et al, 1996;Wasko and Galetti Jr., 1998;Paintner-Marques et al, 2002a. Differences in karyotype structure have been evidenced mainly as divergence in acrocentric chromosomes number.…”

Section: Discussionmentioning

confidence: 99%

Chromosome divergence and NOR polymorphism in Bryconamericus aff. iheringii (Teleostei, Characidae) in the hydrographic systems of the Paranapanema and Ivaí Rivers, Paraná, Brazil

2008

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Cytogenetic studies were carried out in three populations of Bryconamericus aff. iheringii from two hydrographic systems of the Paranapanema and Ivaí Rivers, separated by a watershed, both belonging to the upper Paraná River basin. Specimens had a constant diploid number 2n = 52 chromosomes. However, three karyotype formulae were identified in the three populations: B. aff. iheringii from the Maringá stream had 12M+18SM+8ST+14A (FN = 90); specimens from Keller River showed 8M+28SM+6ST+10A (FN = 94) and specimens from the Tatupeba stream had 8M+20SM+8ST+16A (FN = 88). Nucleolar organizer regions (NORs) were identified by silver nitrate staining and fluorescent in situ hybridization (FISH) with an 18S rDNA probe. Specimens from Tatupeba stream had a simple NOR system located in a terminal position of the short arm of a pair of large submetacentric chromosomes. Ag-NOR and FISH methodologies revealed multiple NORs in specimens of the Maringá stream and Keller River. Differences in chromosome structure and in NOR patterns in the three populations of B. aff. iheringii revealed fixed evolutionary chromosome divergence. Aspects related to karyotypic variations and to geographic isolation of these populations are discussed.

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“…exodon population from the Três Bocas Stream, another tributary of the Tibagi River. Two cytotypes were identified (Table 1), which has been characterized as an intra-population chromosome polymorphism (Paintner-Marques et al 2002a).…”

Section: Discussionmentioning

confidence: 99%

“…Later, Wasko et al (1996) reorganized the karyotypes consisting of 6 metacentric, 10 submetacentric, 16 subtelocentric and 20 acrocentric chromosomes. Although recent cytogenetic studies on different species of the genus disclosed remarkable karyotype diversity, the diploid number remains constant with 2n = 52 chromosomes (Wasko and Galetti 1998;Melo et al 1999;Paintner-Marques et al 2002a, 2003. However, among five Bryconamericus species analyzed by Wasko and Galetti (1998), one presented 2n = 54 chromosomes, and was the only divergent karyotype of Bryconamericus species analyzed to date.…”

Section: Introductionmentioning

confidence: 99%

Occurrence of two cytotypes in Bryconamericus aff. iheringii (Characidae): karyotype analysis by C- and G-banding and replication bands

et al. 2007

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Cytogenetic analyses of Bryconamericus aff. iheringii specimens from the upper Paraná River basin (State of Paraná, Brazil) are provided. They had 2n = 52 chromosomes and two cytotypes with variations in their karyotypic formulae: cytotype I with 12 metacentric, 18 submetacentric, 8 subtelocentric and 14 acrocentric chromosomes with a fundamental number (FN) of 90; cytotype II with 8 metacentric, 28 submetacentric, 6 subtelocentric and 10 acrocentric chromosomes with a fundamental number (FN) of 94. Differences in C- and G-band patterns between the cytotypes, distinguishing marker chromosomes for each karyotype, were reported. The R-band pattern by 5-bromodeoxyuridine incorporation was obtained in chromosomes of the cytotype II sample. In some metaphases, the second pair of submetacentric chromosomes is distinctive: its short arm is heterochromatic (positive C-band), corresponding to a late replication region. In the same cytotype, a G- and R-band size heteromorphism w as recorded in the long arm of pair 9 (submetacentric). These methodologies revealed an actual karyotypic differentiation in the B. aff. iheringii population analyzed. Morphometrical comparative analyses and a discussion of evolutionary aspects of chromosome diversification in species of this genus are provided as well.

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Karyotypic Diversity in a Bryconamericus aff. exodon Population(Characidae, Tetragonopterinae).

Cited by 12 publications

References 11 publications

Cytogenetic Analysis of Three Sympatric Gymnotus Species (Teleostei: Gymnotidae) from the Fundo Stream, MG, Brazil

Cytogenetic Analysis of Three Sympatric Gymnotus Species (Teleostei: Gymnotidae) from the Fundo Stream, MG, Brazil

Chromosome divergence and NOR polymorphism in Bryconamericus aff. iheringii (Teleostei, Characidae) in the hydrographic systems of the Paranapanema and Ivaí Rivers, Paraná, Brazil

Occurrence of two cytotypes in Bryconamericus aff. iheringii (Characidae): karyotype analysis by C- and G-banding and replication bands

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