Effects of developmental age, ambient temperature, and dietary alterationson Delta(12) desaturase activity in the house cricket, Acheta domesticus

Double bond formation in polyunsaturated fatty acids (PUFA) is mediated by desaturase enzymes. Certain insect species have been found to possess a Del ta(12) desaturase, previously thought to occur exclusively in plants. We ha ve begun to characterize this enzyme to determine its relatedness to those found in plants and animals. Desaturase activity can be altered significant ly by a number of environmental factors in protozoa, cyanobacteria, plants, fish, and rats. We present evidence here that Delta(12) desaturase activit y in Acheta domesticus is affected by developmental stage, starvation, diet ary alterations, and fluctuations in ambient temperature. Highest activity is observed during the middle of the penultimate instar and 3 to 6 days aft er adult emergence. Starvation markedly decreases Delta(12) activity, where as resumption of feeding on fat-free or low fat diets increases activity. A rch. Insect Biochem. Physiol. 44:112-119, 2000. (C) 2000 Wiley-Liss, Inc.