Although strains and species in the Brachionus species complex are morphologically similar and closely related evolutionarily, many have dramatically different lifespans, fecundity, and responses to interventions to aging like drugs and diet change. We are characterizing and comparing these differences between strains to understand the degree of conservation in response to aging therapies.
Our previous work showed large differences between 12 strains of Brachionus in their response to caloric restriction (widely considered the best-conserved lifespan extending intervention) and to low temperature (which typically extends lifespan). In both cases, we found that the magnitude and direction of change in lifespan depended on genotype. In the case of caloric restriction, one-third of strains had increased lifespan, one-third had no change in lifespan, and one-third had decreased lifespan. By comparing genotypes and gene expression among strains with different responses, we hope to gain insight to the molecular mechanisms underlying aging and responses to therapies.
Female (left) and male (right) Brachionus manjavacas. Image taken with a polychromatic polarizing microscope. Photo credit: Michael Shribak and Kristin Gribble.
Gribble, K.E., B.M. Moran, S. Jones, E.L. Corey, D.B. Mark Welch. 2018. Congeneric variability in lifespan extension and onset of senescence suggest active regulation of aging in response to low temperature. Experimental Gerontology 114:99-106.
Gribble, K.E., O. Kaido, G. Jarvis, and D.B. Mark Welch. 2014. Patterns of intraspecific variability in the response to caloric restriction. Experimental Gerontology 51:28-37.