| Autor: |
Sczepanski, T. S., Noleto, R. B., Kantek, D. L. Z., Cortinhas, M. C. S., Cestari, M. M. |
| Předmět: |
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| Zdroj: |
Journal of Fish Biology; Dec2007 sc, Vol. 71, p453-460, 8p, 2 Diagrams, 1 Chart |
| Abstrakt: |
Cytogenetic studies were performed on specimens of Atherinella brasiliensis from Laranjeiras Bay (Paraná State, Brazil). All specimens had a diploid number of 48 chromosomes, with a karyotype constituted by 4m+14sm+18st+12a and fundamental number of 84. The C-positive heterochromatin was distributed over the nucleolar organizer regions (NORs) in the centromeric regions and on short arms of metacentric and submetacentric chromosomes. Most of this heterochromatin was AT-rich, except in the NORs, which were rich in GC, as detected by double staining with chromomycin A3/4′-6-diamin-2-phenylindole. Single NORs were located at terminal positions of a submetacentric pair, as confirmed by fluorescent in situ hybridization with 18S rDNA probes. Both techniques showed a size heteromorphism between the homologous chromosomes. The 5S rDNA clusters were located in terminal positions on two chromosomal pairs and also displayed a size heteromorphism. Despite the conserved diploid number, the data on the karyotype microstructure help characterize the cytogenetic profile of this group. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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