Birds Reveal APOBEC1's Ancient DNA-Editing Role
Aswin S Soman, PhD student from the Research group of Dr. Nagarjun Vijay [Department of Biological Sciences, IISER Bhopal] developed a comparative evolutionary genomics framework to decipher APOBEC1 (A1) evolution in birds. Using 81 avian genomes, the study found recurrent A1 disruption and catalytic inactivation across multiple lineages. Avian A1 lacks key mammalian features required for precise apoB RNA editing, including residues and domains needed for RNA binding, dimerisation and cofactor interaction. However, species with higher endogenous retrovirus loads retain stronger G-to-A DNA-editing signatures in LTR retrotransposons, supporting an ancestral antiviral DNA-editing role. The findings suggest that mammalian RNA editing evolved later as an exaptation, while relaxed retroviral pressure promoted repeated A1 loss in birds. For more details, kindly visit https://doi.org/10.1007/s00251-026-01403-4.
