Itsy bitsy genome
Researchers have sequenced the smallest genome yet discovered, a string of DNA belonging to a species of bacterium that lives inside sap-eating insects’ gut cells.
This species, Carsonella ruddii, has a genome of about 160,000 base pairs, the building blocks that make up DNA. In contrast, people’s genomes are about 3 billion base pairs long.
Nancy Moran of the University of Arizona in Tucson and her colleagues began studying C. ruddii’s genome to find out what functions these symbiotic bacteria might perform for their insect hosts. She notes that her team was “very surprised” when the sequence data showed that the microbe’s genome was so tiny.