Study Chiang Mai, Thailand, December 24, 2025 – Researchers report parent-of-origin imprinting of IGF2 and H19 in dogs, highlighting epigenetic influences on early development.
Genomic imprinting is a rare but biologically significant regulatory mechanism in mammals, producing monoallelic gene expression determined by whether an allele is inherited from the mother or father. These differences arise from epigenetic modifications established during gametogenesis and maintained after fertilization. Aberrant imprinting is associated with developmental abnormalities and diseases across species, making its study essential for comparative genetics.
New work examining domestic dogs (Canis familiaris) expands the phylogenetic landscape of imprinting research by demonstrating that two key growth-related genes—IGF2 and H19—exhibit clear parent-of-origin imprinting. In neonatal umbilical cord tissues, investigators identified monoallelic expression patterns consistent with established mammalian imprinting systems. These findings position the dog as an important model species for examining conserved and divergent imprinting mechanisms.
Researchers also identified a putative imprint control region (ICR) associated with IGF2 and H19 and presented evidence for differential methylation of this regulatory region. The umbilical cord displayed somatic methylation patterns, while the male germline showed hypermethylation, reflecting the epigenetic reprogramming cycles characteristic of imprint establishment. Together, these results illuminate fundamental processes guiding canine development.
Understanding imprinting in dogs has broader implications for veterinary medicine and evolutionary biology. Because dogs exhibit profound morphological and behavioral diversity, imprinting mechanisms may contribute to trait variation and disease susceptibility. This work strengthens the dog’s role as a comparative model for studying genetic regulation, evolutionary pressures on imprinting, and the balance between diploidy and parent-specific expression.
Source:
Brabazon, D., Callanan, J., & Nolan, C. M. (2021). Imprinting of canine IGF2 and H19. Animal Genetics.
