Founding Micronuclei: The Buccal Micronucleus assay as useful method to evaluate genomic damage in mammal species

At individual level, genomic damage is one of the most important causes of degenerative and cancer diseases, whereas at population level it represents a factor that could increase the extinction risk. It is known that the levels of genomic damage may be influenced by endogenous factors, like genetic polymorphisms, and by exogenous causes, like environmental exposure to xenobiotics. Among markers of genomic damage, Micronuclei (MNi) were widely used in many population studies. They originate from whole chromosomes or chromosome portions that lag behind during anaphase of nuclear division. MNi can be easily assessed in different cell types, such as erythrocytes, lymphocytes, buccal and exfoliated epithelial cells. The MNi test in exfoliated cells of the buccal mucosa is a noninvasive assay successful used for the evaluation of the genomic damage level in different taxa. This assay was firstly developed for humans, in order to provided data about the genotoxic effects of pollutants, and successively was used to monitoring the health status of different invertebrate and vertebrate organisms, mammals included. Few data are present in literature about the frequency of MNi in mammal species. For example, bats were used to evaluate the effect of air pollution and of different trophic levels on the amount of genomic damage; aquatic mammals (Tursiops truncatus) were used as bioindicator of aquatic pollution and micromammals (Sciurus aureogaster) were used to evaluate the level of MNi in relation to age. In our study, this technique was successful used in order to evaluate the possible stress-induced genomic damage in shelter dogs and cats. We observed a significant difference in the level of genomic damage between shelter and family animals. In conclusion, we can affirm that the MNi assay represents an efficient, reliable, economic and non-invasive technique useful to measure the genomic instability in human and animal populations.