Practice question

Mobile or homing introns are self-splicing Group I or Group II introns containing open reading frames encoding homing endonucleases, often belonging to LAGLIDADG or HNH families, and sometimes combined maturase-endonuclease functions. Homing endonuclease introduces site-specific double-strand break in intron-less allele, stimulating homologous recombination repair using intron-containing genome as donor, thereby duplicating intron into new allele. This selfish element drives super-Mendelian inheritance, spreads despite fitness cost, and links splicing to DNA mobility. This refined regulation supports accurate ribosomal assembly, quality control and translational fidelity under diverse physiological conditions and growth states.