DNA housekeeping in long-lived queen ants
The free radical or reactive oxygen species (ROS) model attributes one of the reasons for ageing to damaging oxidising agents. However, previous studies on the social insect the black garden ant, Lasius niger, have shown that workers have higher expression of ROS removal genes than longer-lived queens. 'The role of somatic mutation in the lifespan difference of queen and worker ants' (ANTAGING) project looked at gene damage and its repair as a reason for ageing and delayed senescence. Using age-matched individuals, they observed 1-day–old and 1-year–old ants for extent of macromolecule damage or mutations. To study expression of DNA repair genes, the researchers used 1-day–old and 2-month–old ants. A refined version of western blotting to detect damaged proteins, and an investigation into the level of physical breaks in DNA, showed little evidence for increased accumulation of detectable damage over one year in workers compared to queens. However, 2-month–old queens express more DNA repair gene expression in leg tissue than 2-month old workers. Interestingly, this did not appear to be the case in brain tissue. Future studies focusing on the timing of genetic and tissue maintenance in queens and workers should elucidate the mechanisms behind ANTAGING results. Overall, the study has furthered understanding of the causes of senescence and molecular strategies that can prolong lifespan.
