Stochasticity Explains Nongenetic Inheritance of Lifespan and Apparent Trade-Offs between Reproduction and Aging

Area of Science:

• Gerontology
• Evolutionary Biology
• Genetics

Background:

• Stochastic effects influence lifespan variation even in genetically identical individuals.
• Cascading effects of aging stochasticity on offspring traits are underappreciated.

Purpose of the Study:

• To investigate the nongenetic inheritance of lifespan in Drosophila melanogaster.
• To explore the relationship between maternal age, offspring lifespan, and reproduction.
• To model aging using reliability theory to explain observed lifespan phenomena.

Main Methods:

• Experimental crosses using genetically identical female fruit flies (Drosophila melanogaster).
• Observation and quantification of lifespan and offspring production.
• Extension of reliability theory of aging with dichotomized physiological units.

Main Results:

• Longer-lived female flies produced longer-lived daughters (nongenetic inheritance).
• Daughters of older mothers exhibited shorter lifespans (Lansing effect).
• Longer-lived flies produced fewer offspring, indicating a trade-off.

Conclusions:

• Stochastic effects alone can explain nongenetic lifespan inheritance, the Lansing effect, and reproduction-lifespan trade-offs.
• Widespread nongenetic inheritance could explain low heritability of lifespan.
• Potential for anti-aging interventions without trade-offs to other physiological functions.