Reports

Unique Sterol in the Ecology and Nutrition of Drosophila pachea

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Science  13 Aug 1965:
Vol. 149, Issue 3685, pp. 758-761
DOI: 10.1126/science.149.3685.758

Abstract

Drosophila pachea, which breeds only in the stems of senita cactus (Lophocereus schottii) throughout the Sonoran Desert, requires the cactus as a dietary supplement when reared on laboratory media. Δ7-Stigmasten-3β-ol, isolated from the cactus or synthesized, can replace the cactus in the diet of flies reared nonaseptically or axenically. Δ7-Cholesten-3β-ol and Δ5, 7-cholestadien-3β-ol could be substituted for the cactus sterol; Δ5, 7-stigmastadien-3β-ol produced infertile females. Cholesterol, 4α-methyl-Δ7-cholesten-3β3-ol, β-sitosterol, stigmasterol, ergosterol, and Δ7-ergosten- 3β-ol did not support larval growth.