Meeting Abstract
Telomeres are conserved nucleotide sequences that protect genomic integrity and naturally shorten during DNA replication; therefore, telomeres are perhaps best known for their negative relationship with age, where higher rates of loss occur earlier in life during rapid growth. However, high variation in telomere length within age groups suggests that age alone cannot explain all variation in telomere dynamics. One possibility is that early life stressors may ‘program’ later telomere dynamics and influence how animals cope with their environment. Here, we tested the hypothesis that maternally-experienced stress influences offspring telomere shortening during postnatal development. Specifically, we administered an immune challenge (i.e. lipopolysaccharide – LPS) to free-living female tree swallows (Tachycineta bicolor) early in the chick provisioning period and measured physiological and performance-related effects of this stressor on females and their chicks. We found that LPS injection led to declines in female nest visitation rates, resulting in significantly slower growth of chicks during the 24-48 hour period of female sickness; however, chicks of LPS-injected females experienced accelerated ‘catch-up’ growth, resulting in no mass difference between treatments by 12 days of age. We also quantified the effects of these maternal immune challenges on chick telomere shortening, with the prediction that chicks experiencing compensatory growth suffer from accelerated telomere attrition and other performance-related costs. Our results explore the intergenerational effects of an immunological stressor on offspring growth and telomere dynamics and in doing so, will provide novel insights into the causes of variation in telomere length.
