High frequency of gaps and brakes in fish chromosomes as a indicator of presence of genotoxic agents in water ecosystems
2005
Fister, S.(Fakultet veterinarske medicine, Beograd (Serbia and Montenegro))
The karyotype of the pike (Esox lucius L.) consists of 50 acrocentric chromosomes. This karyotype is considered to be rather nearest to ancestral, supposed to posses 48 acrocentrics. The analyses of the frequencies of the breaks and gaps of chromosomes in the pike individuals from different localities, in two consecutive years, were showed the highets values, that were above the level of a spontaneous (under the level of 3%) changes. The values were higher than the level of the presumed critical zone (3.0-3.5%) at the localities of the river Sava, especially near its mouth and in the Danube by Visnjica and Grocka, i.e. these localities had a risk of being permanent or periodical contaminated with genotoxic agents. The carp karyotype consists of 2n=104 chromosomes. The values of the frequencies of breaks and gaps in the carp individuals from different localities indicate an increased level - above the critical area (3.0-3.5) at the locality of the river Tamis, that could be the result of a permanent or periodical contamination with genotoxic agents at the time when the investigations were carried out. The similar results were obtained in some other fish species, that confirmed presumption about the existence of some genetic risk, that could be the result of the presence of genotoxic materials in the environment.
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