FATTY-ACID COMPOSITION OF FAT-BODY AND MALPIGHIAN TUBULES OF THE TENEBRIONID BEETLE, ZOPHOBAS-ATRATUS - SIGNIFICANCE IN EICOSANOID-MEDIATEDPHYSIOLOGY

Total and phospholipid fatty acid composition of fat body and Malpighi an tubules from two larval stages, pupae and adults, of Zophobas atrat us were analyzed. Saturated and unsaturated C16 and C18 fatty acids we re major components and varied by life stage and tissue source. Eicosa noid-precursor fatty acids, including 20:3n-6, 20:4n-6 and 20:5n-3, we re present in low quantities and varied by life stage and tissue sourc e. 20:3n-6 was always present in the lowest proportions, indicating th at eicosanoids derived from 20:4n-6 and 20:5n-3 (the 2- and S-series) are likely to be of greater physiological significance in this insect. Fatty acid composition of Z. atratus fat body and Malpighian tubules was independent of diet, suggesting that this insect controls its fatt y acid composition to meet the needs of individual tissues and ontogen etic constraints. Copyright (C) 1996 Elsevier Science Inc.