Abstract

In vertebrate immune systems, antibodies serve as essential defenders against pathogens. Among non-mammalian tetrapods, immunoglobulin Y (IgY) is a predominant antibody class that combines functional characteristics of mammalian IgG and IgE. Although structurally conserved, IgY exhibits notable diversity across species. A recent study by Zhang et al. (2025) uncovers a previously unrecognized mechanism of IgY diversification in the snake Elaphe taeniura (E. taeniura), offering new insights into how evolutionary processes shape immune responses.