Post-Zygotic Modifications and Intra- and Inter-Individual Nucleolar Organizing Region Variations in Fish: Report of a Case Involving Leporinus Friderici
Document Type
Article
Publication Date
8-1-1995
Description
Silver nitrate staining, a rapid and efficient method, has proven to be excellent for nucleolar organizing region (NOR) studies in fish. Some fish appear to have only two NOR-bearing chromosomes in their karyo-type, whereas others probably have several. In the present study we analyzed the NORs of Leporinus friderici, a species that, on the basis of previous studies, has been considered as representative of species with NORs carried by a single chromosome pair. The analyses were performed by a combination of three methods, i.e. silver nitrate staining, staining with the GC-specific fluorochrome chromomycin A3, and in situ hybridization with digoxigenin-labeled probes. The results showed that, although more frequent and conspicuous in a single chromosome pair, the NORs of this species are present in multiple chromosomes. Intra- and inter-individual variations observed by the three methods strongly suggest the occurrence of post-zygotic modifications involving NORs. NOR identification in fish, almost exclusively performed by the silver nitrate method, is currently being re-evaluated by methods such as chromomycin A3 staining and in situ hybridization, which may provide important information leading to a better understanding of chromosome evolution in these animals.
Citation Information
Galetti, Pedro M.; Mestriner, Carlos A.; Monaco, Paul J.; and Rasch, Ellen M.. 1995. Post-Zygotic Modifications and Intra- and Inter-Individual Nucleolar Organizing Region Variations in Fish: Report of a Case Involving Leporinus Friderici. Chromosome Research. Vol.3(5). 285-290. https://doi.org/10.1007/BF00713066 PMID: 7551542 ISSN: 0967-3849