| Autor: |
Cipriano RR; Departamento de Fitotecnia e Fitossanitarismo, Setor de Ciências Agrárias, Universidade Federal do Paraná, Rua dos Funcionários, 1540, Curitiba, Paraná, CEP: 80035-050, Brazil. rogerraupp@gmail.com., Noleto RB; Departamento de Biologia, Universidade Estadual do Paraná, Campus União da Vitória, Praça Coronel Amazonas, União da Vitória, Paraná, CEP: 84600-000, Brazil. rafanoleto@yahoo.com.br., Kantek DL; Taiamã Ecological Station, Instituto Chico Mendes de Conservação da Biodiversidade, Cáceres, Mato Grosso, Brazil., da Silva Cortinhas MC; Laboratório de Crustáceos Decápodes, Instituto de Oceanografia, Universidade Federal do Rio Grande, Rio Grande, Rio Grande do Sul, Brazil., Cestari MM; Departamento de Genética, Universidade Federal do Paraná, Centro Politécnico, Curitiba, Paraná, CEP: 81530-900, Brazil. |
| Abstrakt: |
Cytogenetic studies have assisted in the taxonomic classification of organisms, especially those involving species with highly similar morphologic characteristics, or so-called cryptic species. Strongylura marina and Strongylura timucu collected from Paranaguá Bay, Paraná Coast in Southern Brazil are considered cryptic species, and the identification of interspecific variations based on the number and/or morphology of its chromosomes may serve as differentiating cytotaxonomic markers. Chromosomes of the two species were subjected to different banding and staining methods (C-, Ag-, and DAPI-CMA3), as well as chromosomal mapping of major rDNA (45S), revealed with an 18S probe by fluorescence in situ hybridization (FISH). The pattern of distribution of constitutive heterochromatin showed distinct features involving the pericentromeric and telomeric bands in both species. In S. marina, chromosome 1 represents the main species-specific marker, appearing almost entirely heterochromatic. In both species, the 45S rDNA is located at terminal region of the short arm of the chromosome 6, as detected by silver nitrate staining and FISH. Despite the apparent conserved diploid number of 48 chromosomes, data on the karyotype microstructure characterize the cytogenetic profile of the genus and may allow the establishment of cytotaxonomic and evolutionary inferences for these fishes. |
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