| Autor: |
Terra, Mariana Costa, Takagui, Fábio Hiroshi, Baldissera, Joana Neres Da Cruz, De Lima, Moema C. Costa, Feldberg, Eliana, Dias, Ana L. |
| Předmět: |
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| Zdroj: |
Biologia; Jul2022, Vol. 77 Issue 7, p1995-2003, 9p |
| Abstrakt: |
Among the 23 genera belonging to the Heptapteridae family, Pimelodella stands out with the largest number of species, totaling 82 valid ones. Despite the few species characterized cytogenetically, this genus exhibits considerable variation in chromosomal markers. Thus, this study consists in a cytogenetic characterization of Pimelodella cristata collected in the Central Amazon region, contributing with new cytogenetic data for the genus. This species presented 2n (diploid number) = 46 (22 metacentric + 18 submetacentric + 2 subtelocentric + 4 acrocentric) and nucleolus organizing regions (NORs) coincident with the secondary constriction in the short arm of the acrocentric pair 22. In this same region, rich GC sites were also detected, as well as sequences of 18S ribosomal DNA (18S rDNA) through fluorescence in situ hybridization (FISH), confirming the pattern of simple NORs. Multiple sites of 5S ribosomal DNA (5S rDNA) were observed, totaling four terminal sites on metacentric chromosomes. P. cristata did not follow the heterochromatin distribution pattern frequently reported in the genus, revealing a larger amount of heterochromatin and some interstitial blocks. In addition to the cytogenetic characterization of one population of P. cristata from the Central Amazon region, this study brings a discussion about the main mechanisms related to the karyotypic variability of the genus, based on data available of Pimelodella in the literature associated with the geographic distribution of its species. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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