Carsonella ruddii, a symbiotic bacterium, currently holds the record for having the shortest known DNA.
Details About Carsonella ruddii and Its Minimal Genome
Carsonella ruddii is a fascinating example of genome reduction through evolution. This bacterium lives inside sap-feeding insects (specifically psyllids) and has a mutually beneficial relationship with its host. Over time, Carsonella ruddii has shed genes that are no longer essential because the insect host provides many of the necessary nutrients and functions.
Key Features of Carsonella ruddii's Genome:
- Size: The genome consists of only 159,662 base pairs (or "letters") of DNA.
- Genes: It contains just 182 protein-coding genes.
- Lifestyle: Its symbiotic lifestyle allows it to survive with such a reduced genome. It relies on the host insect for many essential functions.
Why is a Short Genome Significant?
Studying organisms with minimal genomes like Carsonella ruddii helps scientists understand:
- Essential genes: Which genes are absolutely necessary for life.
- Evolutionary processes: How genomes can shrink and adapt to specific environments.
- Synthetic biology: The potential for creating minimal synthetic organisms.
Other Organisms with Small Genomes
While Carsonella ruddii has the shortest known genome as of the referenced date, research in this area is ongoing, and new discoveries may change this. Other bacteria with relatively small genomes include Mycoplasma genitalium.
| Organism | Genome Size (Base Pairs) | Number of Genes | Notes |
|---|---|---|---|
| Carsonella ruddii | ~159,662 | 182 | Symbiotic bacterium living in sap-feeding insects |
| Mycoplasma genitalium | ~580,000 | ~482 | Parasitic bacterium; one of the smallest free-living cells |
In conclusion, Carsonella ruddii boasts the smallest known genome among living organisms studied so far, primarily due to its symbiotic relationship and resulting reduction in required genes.
