Gene loss, repression, amplification, and horizontal acquisition shape galactose/melibiose metabolism in fission yeast

Natural variation in microbial metabolism drives evolutionary adaptation. While galactose utilization is well-studied in budding yeasts, it remains poorly understood in the fission yeast Schizosaccharomyces pombe. Here, we reveal extensive natural variation in galactose utilization across S. pombe isolates, from complete deficiency to exceptionally fast growth.