Comparison between the micronucleus frequencies of kidney and gill erythrocytes in tilapia fish, following mitomycin C treatment

Abstract

The frequencies of mitomycin C and cyclophosphamide-induced kidney and gill erythrocyte micronuclei were compared in Tilapia rendalli and Oreochromis niloticus. Cyclophosphamide (CP) and mitomycin C (MMC) were previously used to investigate fish sensitivity to micronuclei induction in kidney erythrocytes. Fish were treated with a single dose of cyclophosphamide (40 mg/kg) or mitomycin C (2 mg/kg). Peripheral blood samples and kidney blood samples were obtained, 1, 2, 3, 5, 7, and 15 days after the intra-abdominal injection of MMC. T. rendalli showed to be more sensitive than O. niloticus to micronuclei production. Both compounds were used at the maximum tolerated dose (MTD), and mitomycin C proved to be more toxic than cyclophosphamide. The frequency of micronucleated erythrocytes observed varied significantly among the treated individuals. The difference between the kidney and gill micronuclei frequencies was not significant. Higher levels of micronucleated erythrocytes were observed in Tilapia rendalli than in O. niloticus. T. rendalli produced erythrocytes with deformed nuclei, which O. niloticus did not.

Frequency of micronuclei and of other nuclear abnormalities in erythrocytes of the grey mullet from the Mondego, Douro and Ave estuaries—Portugal

“…Experimental data have been consistently proving that MN and other abnormalities appear very rapidly after such exposures. For instance, in an experiment undertaken with two species of cichlids (Palhares and Grisolia 2002), it was verified that fish injected intra-abdominally with either cyclophosphamide or mitomycin C significantly raised the MN rates in erythrocytes within 1 day. Studies with common water pollutants have corroborated those with reference genotoxicants, as in the case of a waterborne assay with an atrazine-based herbicide, which evoked MN in erythrocytes on the goldfish (Carassius auratus) in just 2 days (Cavas 2011).…”

Scenario of Genotoxicity in Fishes and Its Impact on Fish Industry

“…As previously mentioned by Ali and El-Shehawi (2007), these locations display differential environmental stress. Fagr et al (2008) found that peripheral blood of Clarias gariepinus is very sensitive in formation of micronucleus depending upon the environmental stress, and might be by other factors Palhares and Grisolia (2002) compared between the micronuclei frequencies of kidney and gill erythrocytes in tilapia fish, following mitomycin C treatment detecting no significant difference between them. A contrasting observation was recorded by Fagr et al (2008) that the peripheral blood was more sensitive with higher micronuclei frequencies for the damage induced by the aquatic contaminants (approximately 150%) compared with kidney erythrocytes while working on several fish species sourced from different locations in Egypt displaying differential environmental stress.…”

Environmental genotoxicity and cytotoxicity in the offshore zones of the Baltic and the North Seas

“…The assay is well elaborated and allows to evaluate the genotoxicity of compounds at low concentrations and to assess doseresponse relationships of both DNA reactive and non-DNA reactive genotoxins (e.g. aneugens) (Al-Sabti et al, 1994;Palhares and Grisolia, 2002;Pacheco and Santos, 2002; Santos, 2002, 2003;Rodriguez-Cea et al, 2003;Teles et al, 2003) Micronuclei arise from chromosome fragments or whole chromosomes that lag at cell division due to lack of centromere, damage in centromere region, or defect in cytokinesis (Fenech, 2000). MN are small, secondary structures of chromatin, are surrounded by membranes, located in the cytoplasm and have no detectable link to the cell nucleus (Boller and Schmid, 1970;Heddle, 1973;Heddle et al, 1991;MacGregor, 1991).…”