Data from: DNA methylation reflects tissue and caste identity but not parasitism-induced changes in a social insect

The role of DNA methylation in regulating transcriptional activity and
post-transcriptional modifications in insects, particularly in social
insects, remains debated. Social insect castes, primarily determined by
differential gene expression, exhibit pronounced phenotypic differences in
morphology, life history traits, and behaviour. In some ants, parasites
induce divergent phenotypes, but the role of DNA methylation in this
remains poorly understood. In this study, we examined DNA methylation
patterns across different tissues (brain and fat body) and castes (queens
and workers) in the ant Temnothorax nylanderi. We also compared healthy
workers to those infected with the cestode Anomotaenia brevis, which is
associated with changes in lifespan, morphology, and behaviour. Our
results reveal significant differences in gene body methylation across
tissues, which were positively linked to gene expression. We also observed
caste-specific differences in DNA methylation, particularly in the fat
body. Surprisingly, however, we detected no differences in DNA methylation
between cestode-infected and healthy workers, despite pronounced
differences in transcriptional activity, suggesting that other epigenetic
mechanisms exert stronger regulatory control over parasite-induced
transcriptional changes. The pronounced differences in DNA methylation
between tissues and castes, partly associated with transcriptional
variation, warrant further investigation into their functional role,
including the modulation of alternative splicing.