Grandmother Age Effects via Sperm Telomere Length and Egg Telomerase Transcripts

Area of Science:

• Evolutionary biology
• Gerontology
• Reproductive biology

Background:

• The Lansing effect describes how parental age reduces descendant viability.
• Transgenerational age effects and their mechanisms remain poorly understood.
• Parental age effects are crucial for understanding lifespan evolution.

Purpose of the Study:

• To investigate how maternal age affects parental traits in offspring (F1).
• To determine if these offspring traits influence subsequent generations (F2) viability.
• To explore the underlying mechanisms of transgenerational age effects.

Main Methods:

• Experiment using three-spined stickleback.
• Assessed parental traits (body size, spawning, clutch size, egg telomere length).
• Analyzed effects on F1 offspring traits and F2 descendant viability using structural equation modeling.

Main Results:

• Maternal age affected F1 male offspring size and sperm telomere length (TL).
• P0 maternal age influenced F2 embryo TL and hatching success via F1 male sperm TL.
• Interacting effects of maternal age and egg telomerase reverse transcriptase (tert) mRNA impacted F2 hatching success.

Conclusions:

• Maternal age exerts transmissible effects on successive generations through offspring gamete traits (sperm TL, egg tert mRNA).
• This transmissible age effect on grandoffspring TL and viability influences life history evolution.
• Telomere length is linked to health, aging, and lifespan, underscoring the significance of these findings.