Karyotypic and morphological divergence between two cryptic species of Eigenmannia in the Amazon basin with a new occurrence of XX/XY sex chromosomes (Gymnotiformes: Sternopygidae)
Eigenmannia species are widely distributed in the Neotropics, with eight valid species currently recognized. Populations of Eigenmannia from three locations in the eastern Amazon were investigated using cytogenetic and morphological techniques, revealing two taxa designated here as Eigenmannia sp. &...
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| Format: | Article |
| Language: | English |
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Sociedade Brasileira de Ictiologia
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| Series: | Neotropical Ichthyology |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252015000200297&lng=en&tlng=en |
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| author | Danillo S. Silva Luiz A. W. Peixoto Julio C. Pieczarka Wolmar B. Wosiacki Jonathan S. Ready Cleusa Y. Nagamachi |
| author_facet | Danillo S. Silva Luiz A. W. Peixoto Julio C. Pieczarka Wolmar B. Wosiacki Jonathan S. Ready Cleusa Y. Nagamachi |
| author_sort | Danillo S. Silva |
| collection | DOAJ |
| description | Eigenmannia species are widely distributed in the Neotropics, with eight valid species currently recognized. Populations of Eigenmannia from three locations in the eastern Amazon were investigated using cytogenetic and morphological techniques, revealing two taxa designated here as Eigenmannia sp. "A" and Eigenmannia sp. "B". The species differ in three morphometric characters, two meristic characters, and one osteological character. Eigenmannia sp. "A" presents 2n = 34 (22 m/sm+12 st/a) and Eigenmannia sp. "B" presents 2n = 38 (14 m/sm+24st/a) and simple differentiated sex chromosomes of the type XX/XY. In both species the Constitutive Heterochromatin (CH) rich in A-T bases is distributed in the centromeric region of all chromosomes. Eigenmannia sp. "B" also presents CH blocks in the interstitial region of chromosome pairs 8, 9 and X which are positively stained with CMA3, indicating G-C rich regions. The NOR is located on the short arm of chromosome pair 17 of Eigenmannia sp. "A" and on the short arm of pair 14 of Eigenmannia sp. "B". FISH with rDNA probes hybridized to different-sized regions between homologs, suggesting heteromorphism. The differentiation of the X chromosome in Eigenmannia sp. "B" could be the result of amplification of repetitive DNA sequences. |
| first_indexed | 2024-12-20T12:35:49Z |
| format | Article |
| id | doaj.art-315b9380d00142a5a34f47d8af029319 |
| institution | Directory Open Access Journal |
| issn | 1982-0224 |
| language | English |
| last_indexed | 2024-12-20T12:35:49Z |
| publisher | Sociedade Brasileira de Ictiologia |
| record_format | Article |
| series | Neotropical Ichthyology |
| spelling | doaj.art-315b9380d00142a5a34f47d8af0293192022-12-21T19:40:37ZengSociedade Brasileira de IctiologiaNeotropical Ichthyology1982-022413229730810.1590/1982-0224-20140160S1679-62252015000200297Karyotypic and morphological divergence between two cryptic species of Eigenmannia in the Amazon basin with a new occurrence of XX/XY sex chromosomes (Gymnotiformes: Sternopygidae)Danillo S. SilvaLuiz A. W. PeixotoJulio C. PieczarkaWolmar B. WosiackiJonathan S. ReadyCleusa Y. NagamachiEigenmannia species are widely distributed in the Neotropics, with eight valid species currently recognized. Populations of Eigenmannia from three locations in the eastern Amazon were investigated using cytogenetic and morphological techniques, revealing two taxa designated here as Eigenmannia sp. "A" and Eigenmannia sp. "B". The species differ in three morphometric characters, two meristic characters, and one osteological character. Eigenmannia sp. "A" presents 2n = 34 (22 m/sm+12 st/a) and Eigenmannia sp. "B" presents 2n = 38 (14 m/sm+24st/a) and simple differentiated sex chromosomes of the type XX/XY. In both species the Constitutive Heterochromatin (CH) rich in A-T bases is distributed in the centromeric region of all chromosomes. Eigenmannia sp. "B" also presents CH blocks in the interstitial region of chromosome pairs 8, 9 and X which are positively stained with CMA3, indicating G-C rich regions. The NOR is located on the short arm of chromosome pair 17 of Eigenmannia sp. "A" and on the short arm of pair 14 of Eigenmannia sp. "B". FISH with rDNA probes hybridized to different-sized regions between homologs, suggesting heteromorphism. The differentiation of the X chromosome in Eigenmannia sp. "B" could be the result of amplification of repetitive DNA sequences.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252015000200297&lng=en&tlng=enCytogeneticsFISHKnife fishesMorphologySex chromosomes |
| spellingShingle | Danillo S. Silva Luiz A. W. Peixoto Julio C. Pieczarka Wolmar B. Wosiacki Jonathan S. Ready Cleusa Y. Nagamachi Karyotypic and morphological divergence between two cryptic species of Eigenmannia in the Amazon basin with a new occurrence of XX/XY sex chromosomes (Gymnotiformes: Sternopygidae) Neotropical Ichthyology Cytogenetics FISH Knife fishes Morphology Sex chromosomes |
| title | Karyotypic and morphological divergence between two cryptic species of Eigenmannia in the Amazon basin with a new occurrence of XX/XY sex chromosomes (Gymnotiformes: Sternopygidae) |
| title_full | Karyotypic and morphological divergence between two cryptic species of Eigenmannia in the Amazon basin with a new occurrence of XX/XY sex chromosomes (Gymnotiformes: Sternopygidae) |
| title_fullStr | Karyotypic and morphological divergence between two cryptic species of Eigenmannia in the Amazon basin with a new occurrence of XX/XY sex chromosomes (Gymnotiformes: Sternopygidae) |
| title_full_unstemmed | Karyotypic and morphological divergence between two cryptic species of Eigenmannia in the Amazon basin with a new occurrence of XX/XY sex chromosomes (Gymnotiformes: Sternopygidae) |
| title_short | Karyotypic and morphological divergence between two cryptic species of Eigenmannia in the Amazon basin with a new occurrence of XX/XY sex chromosomes (Gymnotiformes: Sternopygidae) |
| title_sort | karyotypic and morphological divergence between two cryptic species of eigenmannia in the amazon basin with a new occurrence of xx xy sex chromosomes gymnotiformes sternopygidae |
| topic | Cytogenetics FISH Knife fishes Morphology Sex chromosomes |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252015000200297&lng=en&tlng=en |
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