Thermobia domestica

Saxena BP Rohdendorf Be. Morphological changes in Thermobia domestica uunder the influence of Acorus calamus oil vapors. Experientia 1974 30 1298-300. 

The firebrat, Thermobia domestica of the order Thysanura, is the most primitive insect found to be capable of dealkylating phytosterols to cholesterol (6). In this study, dietary sitosterol was shown to be converted to cholesterol, and with the inclusion in the diet of an azasteroid that inhibits A -reductase and causes an accumulation of desmosterol, it was also determined that desmosterol was an intermediate in the conversion of sitosterol to cholesterol. To date, this is the most primitive insect that has been examined with respect to sterol metabolism. 

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