Assessment of the Piscine Micronucleus Test as an in situ Biological indicator of Chemical Contaminant Effects

Abstract

The piscine micronucleus test was assessed for sensitivity and practicality as an in situ biological indicator of chemical contaminant exposure by an application to the peripheral blood of wild white croaker (Genyonemus lineatus) collected from polluted and reference areas along the California coast. The several types of variations from the usual erythrocyte nuclear morphology observed in the blood smears collected for this study were described and the frequencies were compared with measured levels of certain classes of contaminants in white croaker bile and liver, and in sediment collected at each site, in addition, the frequencies were also compared with the prevalence of idiopathic lesions in the livers of the croaker. However, the piscine micronucleus test appeared to lack sensitivity to the presence and effects of the measured contaminants because no association was detected between the frequencies of the erythrocyte nuclear variations and levels of chemical contamination, even though most of the observed variations resembled the published descriptions of variations presumed to be nuclear lesions in earlier investigations. Even if the test had been found to be sensitive, the Sow and variable frequencies of the observed nuclear lesions would present a serious difficulty to the useful application of the test.

Genotoxicity of sub-lethal di-n-butyl phthalate (DBP) in Nile tilapia (Oreochromis niloticus) / Genotoksičnost subletalne koncentracije di-n-butil ftalata (DBP-a) u nilskoj tilapiji (Oreochromis niloticus)

“…For a critical review of the methodology cf. Carrasco et al (16). NAs were of four subtypes: (i) binucleated; (ii) blebbed nuclei; (iii) lobed nuclei; (iv) notched nuclei.…”

Baseline micronuclei and nuclear abnormalities frequencies in native fishes from the Paraná River (Argentina)

“…The NA were distinguished in Notched, Lobed, and Blebbed nuclei, according to the classification proposed by Carrasco et al (1990). Furthermore, two types of NA found in the studied individuals, which were denominated "Eightshaped" (nuclei presenting a constriction acquiring an eight shape) and "Bud" (buddings partially separated from the nucleus), were added.…”

“…Micronuclei (MN) arise from whole chromosomes or acentric fragments that are delayed during anaphase, either by the lack of centromeres or by damage to the mitotic spindle (Schmid, 1975). In addition, changes in the normal morphology of the nuclei are also considered indicators of genotoxic damage, described by Carrasco et al (1990) as nuclear abnormalities (NA), and constitute a complementary analysis to the scoring of micronuclei.…”

Untitled

“…The counting of NAEs on the microscope slides was performed under microscopy-immersion light. The slides were observed with an optical magnification of 1000 times, scoring an average of 1000 mature mononucleated erythrocytes as described by Carrasco et al [19].…”