The Chromosomal Aberration test and Mitotic Index as biomarkers of geno and cytotoxicity on the native Broad snouted caiman (Caiman latirostris)

CHACÓN, CAMILA; LÓPEZ GONZÁLEZ, EVELYN; POLETTA, GISELA L.

MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2021

1383-5718

In the present study, we evaluate the sensitivity of the chromosomal aberrations (CA) and mitoticindex (MI), on peripheral blood lymphocytes (PBLs) of Caiman latirostris, after ex vivo exposure tothe known alkylating agent MMS. The MN test was applied as a complementary biomarker ofclastogenicity/aneugenicity previously used in this species. Two different concentrations of MMS (10 and 20 μM) were tested in cultured peripheral blood and compared to a negative control (NC, 0 μM MMS). The results indicated significant differences in the MI and the FMN in both concentrations of MMS, respect to the NC (p < 0.01). As the concentration of MMS increases, the number of metaphases observed is lower (MINC = 8.68 ± 2.15 vs MI10μM = 5.29 ± 1.29 and MI20μM = 2.56 ± 1.13).At the same time, the number of cells with MN increases (MNNC = 3.63 ± 1.15 vs MN10μM = 7.40 ±1.26 and MN20μM = 8.50 ± 2.00), as well as the percentage of aberrant metaphases (%AMNC = 33.98 ± 16.9 vs %AM10μM = 63.90 ± 15.97 and %AM20μM = 66.56 ± 7.49; p < 0.05). The types of CA identified were: chromosome and chromatid breaks, chromosomal rearrangements, monosomies and nulisomies, with significantly higher values in exposed groups. This study evidences a relation between the CAs and the FMN that allow us to establish a comprehensive view of damage at the genetic level, being two excellent biomarkers of clastogenic/aneugenic damage. In addition, the characterization of the types of CAs found in this species is relevant for future studies. The incorporation of the MI and CA test as indicators of cytotoxicity and genotoxicity in C. latirostris, will provide important information on the possible damage generated by xenobiotics in the progression of the cell cycle and genetic material, before imbalances could occur in the health of the exposed organisms.