Uric acid in wood-eating termites

Abstract

Uric acid (UA) was present in termites as assessed by paper and thin layer chromatography, by U.V. spectroscopy, by reactivity with uricase, and by gas chromatography coupled to mass spectrometry. Specimens of six species ( Reticulitermes flavipes, R. virginicus, Coptotermes formosanus, Marginitermes hubbardi, Paraneotermes simplicicornis, and Cryptotermes cavifrons) contained UA in amounts accounting for between 1 and 45% of the termites' dry weight and for between 4 and 69% of the termites' total nitrogen. Almost all of the UA in R. flavipes was associated with fat body tissue. Faeces contained less than 0.2% of its weight as UA. During 15 months of captivity, UA in R. flavipes workers increased from 1.7% to 45.4% of the insects' dry weight at a linear rate of 2.7% per month. Elemental analyses of termites during this period indicated that synthesis of UA occurred, in part, at the expense of some endogenous nitrogen and carbon. Compounds tentatively identified as inosine and kynurenic acid were also present in termite extracts. Results indicate that termites can store large quantities of UA internally, but they do not void the purine in significant amounts despite the lack of detectable uricase activity in termite tissues.