The Missing Piece: Functional Telomerase Restored in the Beetle Model

The red flour beetle Tribolium castaneum yielded the first resolved telomerase reverse transcriptase (TERT) structure but lacked a known telomerase RNA (TR). We identify two TR paralogs in Tribolium, confirm their expression, and reconstitute active telomerase in vitro. Extending this approach across Coleoptera, we detect TR homologs in diverse beetle lineages, with conserved cores but lineage-specific template and telomeric DNA variants. Our findings establish Tribolium as a powerful model for telomerase biochemistry, illuminate the evolutionary plasticity of beetle telomere maintenance, and reveal a consistent lack of telomerase in several derived Scarabaeoidea subfamilies, pinpointing its evolutionary loss within this beetle clade.