SpeakerMichael Petrascheck, Asst. Prof in Molecular Biology @ Scripps University, Host: Eric Terry
Date and LocationWednesday April 27, 2016 11:00am to 12:00pm
Abstract: Interventions that extend lifespan are generally thought to slow the course of ageing across the lifetime of an organism. An alternative possibility however would be that aging, like development, progresses in stages and that some longevity mechanisms prolong a specific stage by postponing the transition from one stage to another. As a molecular description of physiological age remains elusive, it has not been possible to distinguish these possibilities. Ageing causes a profound loss of synchronized gene expression that is evolutionarily conserved from worms to humans. This loss of transcriptional synchrony, which we have termed “transcriptional drift”, parallels the age-associated loss of homeostatic capacity and provides a quantifiable measure for physiological age. Measuring transcriptional drift in C. elegans allowed us to dissociate physiological age from chronological age, and to reveal that inhibiting serotonergic signals extends lifespan by delaying the transition from young to middle age. Thus, inhibiting serotonergic signals exclusively prolonged the youthful stage of life suggesting that ageing occurs in stages and that serotonergic signals promotes the transition from young to middle age.