Short-lived African turquoise killifish shed light on the evolutionary basis of vertebrate ageing
For this week’s Departmental Seminar we were fortunate to hear from Dario Valenzano, one of the main investigators pioneering the African turquoise killifish (Nothobranchius furzeri) as a model organism for vertebrate ageing and lifespan studies.
Dario explained how lifespan as a trait varies dramatically across different experimental model organisms for ageing research; ranging from the few hour lifespan of May flies, to animals such as planarians that do not age. Killifish are known to be the shortest-lived vertebrate (4 months in the GRZ strain) that have been reared in laboratory conditions.
Ageing is considered an important risk factor for many human diseases, and studying the killifish in a relatively suitable timeframe can provide the insight into the ageing and longevity phenotypes characterised by cancer, pigment loss, neurodegeneration and deterioration in motor and learning skills.
In collaboration across other labs, Dario and his team have developed toolkits that enable killifish to be studied as model organisms like microsatellite-based linkage maps – they can create a fully sequenced, assembled and annotated genome. In addition, they are able to efficiently generate stable transgenic lines for the use of functional studies. By doing several genetic crosses between short-lived and longer-lived strains and by scoring individuals based on their survival, the team are able to do QTL mapping for longevity in killifish. At a locus placed on the sex chromosome, they identified a very strong QTL associating with longevity that is predictive of how long they live.
Now for the last and most exciting part of his talk, in my opinion: Dario introduced his most recent publication on how the gut microbiota (GM) in killifish may affect the ageing process. Transferring GM from young animals to middle-aged fish after antibiotic treatment extended lifespans. Like younger individuals, the middle-aged fish showed an overall healthier physiology and maintained a more diverse microbial community. So, could manipulation of GM in mammals be beneficial for prevention or delay the onset of age-related diseases?
I believe that we all thoroughly enjoyed Dario’s talk, and we are very excited to hear about his future work looking into more detail about how the GM from young fish confers a benefit and performing similar experiments in mice. We were all very grateful to Dario for sharing his outstanding work with us and certainly looking to hopefully having him back again in the future.