A new study has corrected the flawed genome of a worm that serves as the standard model organism for genetic research.
Reassessing The C. Elegans
The Caenorhabditis elegans, the first multicellular eukaryote to have its genome sequenced, shares many genes and molecular pathways with humans. As a result, it is often used to study human diseases such as cancer and test drug treatments.
The study of C. elegans is based on a single strain called N2. However, according to a new study, because many individual laboratories have, over the years, started to grow their own strains, morphing has occurred.
"Over the last decade, with more advanced genetic experiments using high levels of DNA sequencing, scientists were alarmed to discover that there is no longer a single laboratory strain that everyone was using," shared Eric Schwartz, an assistant research professor at Cornell University's Department of Molecular Biology and Genetics. "Over 40 years there have arisen many different N2 strains; we can't rely on any one of them to do experiments."
A New Standard
In the study published in the journal Genome Research on Thursday, May 23, Schwartz and his collaborators described the single genetically-clean strain called VC2010.
The international team used cutting-edge techniques to sequence the genome of VC2010. According to Schwartz, the project would not have been done if not for the new genome sequencing technology that could read thousands of base pairs from a single DNA molecule. Earlier technology allowed scientists to read to only up 150 nucleotide letters at a time.
"You are literally adding two percent," he commented. "If the mutation [you seek] happens to be within that hidden two percent, now you have a chance to spot it."
As part of the study, the researchers also compared VC2010 to N2 genome. They expected a near-perfect match, but they instead found 2 million nucleotides in addition to the 100 million nucleotides that they were hoping to find.
Schwarz said that similar issues are occurring in other standard genomes, including humans. He stated that having the true complete DNA of an organism is not as easy as scientists initially thought. He also shared that other laboratories have started reassessing other genomes.
The findings, he said, has implications for the field of synthetic biology.