Looking for genetic effects of polluted anthropized environments on Caiman crocodilus crocodilus (Reptilia, Crocodylia): A comparative genotoxic and chromosomal analysis

Abstract

The Amazon aquatic ecosystems have been modified by the human population growth, going through changes in their water bodies and aquatic biota. The spectacled alligator (Caiman crocodilus crocodilus) has a wide distribution and adaptability to several environments, even those polluted ones. This study aimed to investigate if a Caiman species living in urban streams of Manaus city (Amazonas State, Brazil) is affected by environmental pollution. For that, it was used classical and molecular cytogenetic procedures, in addition to micronucleus and comet assays. Although the karyotype macrostructure remains unaltered (2 n = 42 chromosomes; 24 t + 18 m/sm; NF = 60), the genotoxic analysis and the cytogenetic mapping of repetitive DNA sequences demonstrated that polluted environments alter the genome of the specimens, affecting both the chromosomal organization and the genetic material.

Keywords

• Fluorescence in situ hybridization
• Nucleolus organizer region
• Interstitial telomeric sites
• Comet assay
• Micronucleus test