David Nelson, PhD, professor in the Department of Microbiology, Immunology and Biochemistry in the College of Medicine at UTHSC has co-authored a paper that provides insight into the lifestyle and unique survival of the Asian longhorned beetle, a tree eating insect. It belongs to a large group (greater than 35,000 species) of longhorned beetles that feed on wood. This is the first member of that group to have its genome sequenced. The findings were published in the latest edition of open access journal Genome Biology.
The paper titled,” Genome of the Asian longhorned beetle (Anoplophora glabripennis), a globally significant invasive species, reveals key functional and evolutionary innovations at the beetle-plant interface,” focuses on the beetle’s genes used to gain entry to host plants and eat wood. The digestion of wood is very difficult. Specifically, the biochemical digestive process used by the beetle to live off of trees by eating their wood is discussed.
The Asian longhorned beetle was introduced from Asia in untreated wood packing crates in the late 1980s and early 1990s. It feeds on more than 100 species of trees, but it prefers maples. By comparing the genome with 14 other insect genomes, the closest neighbor genetically is the mountain pine beetle that is causing major damage to forests in the West and Pacific Northwest.
“The beetle genome has a large collection of specialized enzymes that are dedicated to breaking down plant cell wall components and digesting them to get sugars from them to live on,” said Dr. Nelson. “This is good for the insect, but bad for the trees.”
Nelson collaborated with 66 authors from 31 different institutions on this project. His specific role was to find, assemble and name the cytochrome P450 genes, or genes that code enzymes that metabolize many chemicals. “In humans, they help us to detoxify drugs that we take and other chemicals that we consume in our food,” he said. “In the beetle, some of the cytochrome P450s act to detoxify the host plant defense chemicals intended to protect the plant. That is why the set of 106 cytochrome P450s is so interesting in this beetle. It is a large set of these genes. Some of these genes seem to be expanded into more copies to help the beetle in its quest for food, by counteracting the plants defense system.”
Since this information is now available, the development of a pesticide that inhibits some of these key enzymes may be possible, preventing further damage to trees.
The full article can be read at http://genomebiology.biomedcentral.com/articles/10.1186/s13059-016-1088-8