Evolution, diversity and composition of the protist community in the hindgut of Heterotermes tenuis, a subterranean termite

Subterranean termites (Rhinotermitidae) are responsible for most of the wood damage caused by termites in the United States. They are also important contributors in increasing soil fertility through wood decomposition, especially in arid regions. Their ability to digest lignocellulose depends on a mutualistic and obligate symbiosis with two groups of protists, Parabasalia and Oxymonadida. These symbionts live inside the hindgut of the lower termites and are vertically inherited through proctodeal trophallaxis. Each species of lower termite harbors a unique symbiotic protist community in its hindgut. Therefore, the diversity and the composition of each species' protist community is largely a result of co-speciation between the symbionts and their host. Here, we investigate the composition of the protist community in the guts of one species of Rhinotermitidae, Heterotermes tenuis, using next-generation sequencing techniques. The termites were collected in various locations in the Southwest region of the United States, Central and South America, and preserved in ethanol. We found that the protist community in the hindgut of Heterotermes tenuis had a high variability across the different locations. This study suggests that there may be other drivers that are shaping the protist community in these lower termites, altering our view of this ancient and ecologically important symbiosis.