Genetic damage induced by trophic doses of lead in the neotropical fish Hoplias malabaricus (Characiformes, Erythrinidae) as revealed by the comet assay and chromosomal aberrations

Abstract

The effects of clastogenic or mutagenic agents have rarely been studied in neotropical fish species exposed to contaminated water. In this study, the genetic damage caused by lead in the widely distributed South American fish, Hoplias malabaricus, was assessed using the comet (SCGE) assay and by testing for chromosomal aberrations. Eighteen specimens were acclimatized to laboratory conditions and then chronically exposed to contaminated food by feeding prey (Cyprinus sp.) injected intraperitoneally with doses of inorganic lead adjusted to give a contamination level of 21 µg of Pb 2+ .g -1 net weight of H. malabaricus. Three fish were sampled for chromosomal analysis after four doses (18 days) and another three after eight doses (41 days) of lead and the results then compared with three untreated controls kept under lead-free conditions. An additional six treated fish and three controls were sampled for the comet assay after 13 doses (64 days). Exposure to lead significantly increased the frequency of chromosomal aberrations and the frequency of tailed cell nuclei, the latter indicating DNA damage. These results show that H. malabaricus is a useful biological model for screening the clastogenic effects of lead and possibly other xenobiotics. The genetic damage seen here illustrates the need to investigate the potential effects of heavy metals on fish species in South America.

Toxicity Study of Lead Nitrate on Freshwater Fish Cirrhina Mrigala.

“…Heavy metals tend to accumulate in the biosphere by virtue of their non-biodegradable nature. It is known that accumulation of heavy metals in tissues and organs results in cellular and molecular damage in various species (Cestari et al, 2004;Flora et al, 2012). The present study demonstrates the morphological and biochemical effects associated with the accumulation of the heavy metal lead in adult fish, Cirrhina mrigala (Common Indian Carp).…”

The Effects of Sediments Burdened by Sewerage Water Originating in Car Batteries Production in the Klenice River (CZ)

“…The most frequent ways of damage to the DNA of the test fish were various chromosomal abnormalities, including chromatid gaps and breaks, chromosomal fragmentation, chromatin decondensation and perientric inversions. Chromatid breaks were the predominant chromosomal aberrations after treatment of lead (Cestari et al 2004). The mutagenic or clastogenic activities of lead are related to disturbances in enzyme regulation that probably affect the replication, translation and repair of genetic material (Goyer and Moore 1974).…”

“…In the study by Cestari et al (2004) a substantial negative impact of lead on the genetic material of fish cells was proven. The most common ways of damaging DNA in the tested fish have included various chromosomal abnormalities, comprising chromatid gaps and breaks, chromosomal fragmentation, chromatin decondensation and perientric inversions.…”

DNA damages promoted by the essential oil from leaves of Casearia sylvestris Sw. (Salicaceae)

“…The procedure of comet assay was performed as described by Tice (2000), Cestari et al (2004), and Miyaji et al (2004) with modifications. Briefly, for each slide, 50 nuclei were randomly observed, always from the left to the right side, and total scoring (TS) was by obtained multiplying the number of cells in each class (nx) by the damage class (TS = (0 × n0) + (1 × n1) + (2 × n2) + (3 × n3) + (4 × n4)), ranging from 0 to 150 (Dantas et al, 2002).…”