Iowa State University (ISU) researchers have overcome the quirks of the
soybean cyst nematode's DNA to sequence its genome. Soybean cyst nematodes
are parasitic roundworms that infect soybean roots and devastate yields in
infected fields. Nematode populations not only build up in fields but stay
The challenges with the genetics of the soybean cyst nematode kept
scientists from assembling the full genome for years. The researchers
sequenced the genome first by sequencing smaller portions and then piecing
those portions together into the full genome. About a third of the
nematode's 29,769 genes are repetitive, which complicated the sequencing and
assembly process, said Rick Masonbrink, an associate scientist in the ISU
Office of Biotechnology and lead author of the study.
Andrew Severin, co-author of the study and manager of the ISU Genome
Informatics Facility, likened the genome to a jigsaw puzzle of a blue sky in
which all the pieces are identical in shape and color. But long-read
sequencing technology made it possible to assemble a high-quality genome.