title: Biological monitoring and B chromosome frequency in Bagre (Rhamdia quelen) in southeast Brazil.
abstract: The genus Rhamdia presents B chromosomes which appear to be present in most species of the genus and thus represent an important characteristic in the evolutionary process. Furthermore, variations in environmental conditions can induce the presence of B chromosomes generated by alterations in the cell cycle, due to the interference from pollutants. The present study aimed to evaluate the cytogenetic aspects of individuals of a population of Rhamdia quelen collected in three areas with differing standards of water quality in the River Uberabinha, a region of the County of Uberlandia, Minas Gerais, Brazil. The Piscine Micronucleus Test results indicate significant genotoxic and cytotoxic potential at the sampling Sites. The chromosome count yielded the modal number 2n=58 with variance between zero and seven B chromosomes. The highest frequency of B chromosomes and the presence of karyotypes with seven supernumerary chromosomes occurred at Site 3, referring, thus, to the location of the highest genotoxic potential. There was a positive correlation between the presence of B chromosomes and the reduction in environmental quality. Therefore, the process of bioaccumulation of heavy metals in aquatic environments may be crucial to determine the presence of B chromosomes.
authors.affiliation: Federal University of Uberlândia-UFU, Department of Genetics and Biochemistry, Umuarama Campus, CEP 38400-902 Uberlândia, MG, Brazil. Electronic address: edimarcampos@yahoo.com.
authors.forename: Edimar Olegário
authors.initials: EO
authors.lastname: de Campos Júnior
authors.affiliation: Federal University of Uberlândia-UFU, Department of Genetics and Biochemistry, Umuarama Campus, CEP 38400-902 Uberlândia, MG, Brazil.
authors.forename: Boscolli Barbosa
authors.initials: BB
authors.lastname: Pereira
authors.affiliation: Federal University of Uberlândia, Institute of Biology, Department of Genetics and Biochemistry, Campus Umuarama, CEP 38400-902 Uberlândia, MG, Brazil.
authors.forename: Sandra
authors.initials: S
authors.lastname: Morelli
authors.affiliation: Federal University of Uberlândia, Institute of Geography, Department of Geography, Campus Santa Mônica, CEP 38405-000 Uberlândia, MG, Brazil.
authors.forename: Erich Vectore
authors.initials: EV
authors.lastname: Pavanin
authors.affiliation: Federal University of São Paulo-USP, Institute of Chemistry Department of Chemistry, Campus Santa Mônica, CEP 38405-000 Uberlândia, MG, Brazil.
authors.forename: Luiz Alfredo
authors.initials: LA
authors.lastname: Pavanin
mesh_terms: D059786:Abnormal Karyotype / Q000662:veterinary*; D000818:Animals; D001938:Brazil; D002397:Catfishes / Q000145:classification / Q000235:genetics*; D002875:Chromosomes / Q000187:drug effects / Q000235:genetics*; D004784:Environmental Monitoring; D005260:Female; D059785:Karyotype; D008297:Male; D019216:Metals, Heavy / Q000633:toxicity*; D015162:Micronucleus Tests; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D060753:Water Quality
chemical_list: D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D014867:Water
keywords: Biomonitoring; Cytogenetic; Micronuclei; Supernumerary chromosome