Perinatal variation and covariation of oxidative status and telomere length in yellow-legged gull chicks

Abstract

The perinatal period is critical to survival and performance of many organisms. In birds, rapid postnatal growth and sudden exposure to aerial oxygen around hatching markedly affect the chick redox status, with potentially negative consequences on physiology mediated by oxidative stress. In addition, telomere length (TL) undergoes reduction during birds’ early life, partly depending on oxidative status. However, relatively few studies have focused specifically on the changes in oxidative status and TL that occur immediately after hatching. In this study of the yellow-legged gull Larus michahellis, we found that chicks undergo a marked increase in plasma total antioxidant capacity and a marked decrease in the concentration of pro-oxidant molecules during the first days after hatching. In addition, TL in erythrocytes decreased by 1 standard deviation over the 4 days post-hatching. Body mass and tarsus length covaried with total antioxidant capacity and concentration of pro-oxidants in a complex way, that partly depended on sex and laying order, suggesting that oxidative status can affect growth. Moreover, TL positively covaried with the concentration of pro-oxidant molecules, possibly because retention of high concentrations of pro-oxidant molecules results from mechanisms of prevention of their negative effects, including reduction in TL. Thus, this study shows that chicks undergo marked variation in oxidative status, which predicts growth and subsequent TL, prompting for more studies of the perinatal changes in the critical post-hatching stages.

Different qPCR master mixes influence telomere primer binding within and between bird species

“…Since the initial proposal of qPCR to measure telomere lengths in birds, its use has become the preferred strategy to study telomere dynamics, promoting a growing and exciting research field with dozens of articles published in the last decade. The MMqPCR assay was used in a restrict number of bird species (Parolini et al , ), while the monoplex qPCR assay has been applied on a wide diversity of species by adapting the original method reference (Criscuolo et al ), often without considering its performance or adequacy in each newly tested species. However, several preanalytical and analytical factors involving the qPCR telomere assay (e.g.…”

Telomere shortening is associated with corticosterone stress response in adult barn swallows

“…These may include social environment ( Costanzo et al 2017 ), nutritional conditions ( Young et al 2017 ), environmental factors such as traffic noise ( Injaian et al 2019 ), and exposure to elevated GC levels ( Haussmann et al 2012 ; Herborn et al 2014 ). In addition, telomere attrition does not proceed at a stable rate across life stages; in birds for example telomere shortening can be more pronounced in early life ( Parolini et al 2015 , 2019 ) compared with adulthood ( Hall et al 2004 ; Pauliny et al 2012 ).…”