• Many insects rely on heritable bacterial endosymbionts for essential nutrients that they cannot get through their diet. • A new study, published in Nature Communications, indicates that the genomes of these symbiotic bacteria often shrink over time. • Some of these bacteria, which live inside certain insect cells, have lost so many genes that they have broken the record for the tiniest genome ever found-almost blurring the lines between organelle and bacteria.
Article Summaries:
- A recent study in Nature Communications reports that symbiotic bacteria living inside planthopper insects have achieved the smallest known non‑organelle genome. These endosymbionts, which supply essential nutrients that the insects cannot obtain from their diet, have undergone extensive genome reduction over evolutionary time. The researchers found that the bacteria have lost a significant number of genes, shrinking their genomes to a size that rivals that of organelles such as mitochondria. This discovery highlights the extreme specialization of insect‑associated microbes and blurs the traditional distinction between free‑living bacteria and organelle‑like entities.
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