Data from: Intergenerational effects on offspring telomere length; interactions among maternal age, stress exposure and offspring sex

Offspring produced by older parents often have reduced longevity, termed
the Lansing Effect. Because adults usually have similar aged-mates, it is
difficult to separate effects of maternal and paternal age, and
environmental circumstances are also likely to influence offspring
outcomes. The mechanisms underlying the Lansing Effect are poorly
understood. Variation in telomere length and loss, particularly in early
life, is linked to longevity in many vertebrates and therefore changes in
offspring telomere dynamics could be very important in this context. We
examined the effect of maternal age and environment on offspring telomere
length in zebra finches. We kept mothers under either control (ad lib
food) or more challenging (unpredictable food) circumstances and
experimentally minimised paternal age and mate choice effects.
Irrespective of the maternal environment, there was a substantial negative
effect of maternal age on offspring telomere length, evident in
longitudinal and cross sectional comparisons (average of 39% shorter).
Furthermore, in young mothers, sons reared by challenged mothers had
significantly shorter telomere lengths than sons reared by control
mothers. This effect disappeared when the mothers were old, and was absent
in daughters. These findings highlight the importance of telomere dynamics
as inter-generational mediators of the evolutionary processes determining
optimal age-specific reproductive effort and sex allocation.