Paternal grandparental exposure to crop failure or surfeit during a childhood slow growth period and epigenetic marks on third generational growth-, glucoregulatory and stress genes
This latest in our series of papers describes transgenerational methylation related to midchildhood food availability in 19th century Overkalix, Sweden. Failed vs. bountiful crops differentially influenced methylation in grandchildren of paternal grandparents exposed to feast or famine during their Slow Growth Period (SGP), a sensitive period preceding the pre-pubertal growth spurt. In this case-study of 8 tracked 75-year old progeny with differential ancestral exposure, we found, in 40 posited gene ontology pathways, 39 differentially methylated CpG regions (DMRs) related to famine, excess food and food-insecurity stress, 9 of which with DMRs above 5%. Three gene ontology terms (GOs) \"insulin processing\", \"adipose development\" and \"hypothalamus development\" were key, with DMRs >14%. An unbiased test of known pathways revealed four nuclear transcription factors upstream of promotors repressing the pathway following paternal grandparental famine experience, as well as 4 upregulated GOs with average DMRs >20%. We conclude that this is the first demonstration of human transgenerational inheritance of epigenetic marks following ancestral childhood exposure to variable food availability inducing early developmental origins of adult disease.