When inequality is more than 'skin-deep': Social status leaves traces in the epigenome of spotted hyenas in TanzaniaSpotted hyenas resting at the communal den in the Serengeti National Park in Tanzania . Credit: Sarah Benhaiem/Leibniz-IZW
"We could, for the first time, provide evidence for epigenetic signatures of social inequalities in both young and adult spotted hyenas," says Dr. Alexandra Weyrich, head of the working group"Wildlife Epigenetics" in the Leibniz-IZW Department of Evolutionary Genetics and senior author of the paper. Interestingly, these genes were more methylated in low-ranking adult females but not in cubs. This could indicate an adjustment of low-ranking adult females to higher energetic costs of frequent long-distance commuting, a behavior not displayed by cubs.
The use of samples collected in a non-invasive manner is one of the strengths of the investigation, the authors surmise."The capture methylation method we used enriches methylated DNA as well as mammalian DNA, which improved the amount of hyena DNA over bacterial DNA and the quality of the sequencing data," explains Weyrich.
Spotted hyenas are highly social and a model for social status-related differences in life history traits that are accompanied by differences in physiological processes and health. In hyena clans, females and their offspring socially dominate all immigrant males, and social status is behaviourally"inherited" by cubs from mothers who gain privileges associated with maternal social status., young hyenas receive social support from their mothers during interactions with group members.