Permalink : http://hdl.handle.net/2115/45198

ショウジョウバエの耐寒性の獲得にかかわる生化学的なメカニズムを探るため, キイロショウジョウバエの低温麻痺からの回復が早い系統（CR）, 遅い系統（CS）, 中間的な系統（CTL）を人為選択あるいは自由交配によって作製した. これらの系統から生体膜の流動性にかかわるリン脂質を抽出し, 脂肪酸の組成をガスクロマトグラフィーによって調べたところ, 系統間で大きな違いが見られた. 耐寒性の獲得・喪失にこれらリン脂質脂肪酸の変化がどのように関わっているのかについて議論する.
To clarify biochemical mechanisms underpinning acquisition of cold tolerance, I investigated the fatty acid compositions of phospholipids in Drosophila melanogaster lines showing rapid (CR), intermediate (CTL), or slow (CS) recovery from chill coma, which were established by artificial selection or by free recombination without selection. Compared to CTL, CS showed a low composition of dienoic acids and a small number of double bonds in the fatty acids. The ratio of unsaturated fatty acids and saturated fatty acids (UFAs/SFAs) was significantly lower in CS than in CTL. CR had higher monoenoic acid composition and lower dienoic acid composition than CTL. In addition, the amount of SFAs was lower and therefore the UFAs/SFAs ratio considerably higher in CR than in CTL. These changes in phospholipid fatty acids probably contributed to losing and maintaining the homeoviscosity of the cellular membranes in CS and CR, respectively, at low temperatures and therefore produced their distinct phenotypes in recovery from chill coma.