Sex-specific changes in autosomal methylation rate in ageing
common terns
Britta S. Meyer1, Maria Moiron2,
Calvinna Caswara3, William Chow4,
Olivier Fedrigo5, Giulio Formenti5,
Bettina Haase5, Kerstin Howe4,
Jacquelyn Mountcastle5, Marcela Uliano-Silva3,4§,6, Jonathan Wood4, Erich D.
Jarvis5, 7, Miriam Liedvogel*1,2§,
Sandra Bouwhuis*2
*equal contributions
§current address
1 Max Planck Institute for Evolutionary Biology,
Behavioural Genomics; August-Thienemann-Str. 2; 24306 Plön; Germany
2 Institute of Avian Research; An der Vogelwarte 21;
26386 Wilhelmshaven; Germany
3 Berlin Center for Genomics in
Biodiversity; Königin-Luise-Straße 2-4 Gartenhaus; 14195 Berlin
Germany
4 Wellcome Sanger Institute, Wellcome Genome Campus,
Cambridge CB10 1SA, UK
5 The Rockefeller University, 1230 York Avenue, New
York, NY 10065, USA
6 Department of Evolutionary Genetics, Leibniz
Institute for Zoo and Wildlife Research (IZW)
7Howard Hughes Medical Institute, 4000 Jones Bridge
Rd, Chevy Chase, MD 20815
Corresponding author: bmeyer@evolbio.mpg.de
Abstract
Senescence, an age-related decline in survival and/or reproductive
performance, occurs in species across the tree of life. Molecular
mechanisms underlying this within-individual phenomenon are still
largely unknown, but DNA methylation changes with age are among the
candidates. Using a longitudinal approach, we investigated age-specific
changes in autosomal methylation of common terns, relatively long-lived
migratory seabirds known to show senescence. We collected blood at 1-,
3- and/or 4-year intervals, extracted DNA from the erythrocytes and
estimated autosomal DNA methylation by mapping Reduced Representative
Bisulfite Sequencing reads to a new reference genome. We found autosomal
methylation levels to decrease with age within females, but not males,
and no evidence for selective (dis)appearance of birds of either sex in
relation to their methylation level. Moreover, although we found
positions in the genome to consistently differ in their methylation
levels, individuals did not show such strong consistent differences.
These results pave the way for studies at the level of genome features
or specific positions, which should elucidate the functional
consequences of the patterns we observe, and how they translate to the
ageing phenotype.
Keywords: aging, avian senescence, epigenetics, ontogeny, RRBS,