Gibbs A, Kuenzli M, Blomquist G J
Department of Ecology and Evolutionary Biology, University of California, Irvine 92717, USA.
Arch Insect Biochem Physiol. 1995;29(1):87-97. doi: 10.1002/arch.940290108.
We examined the biophysical properties of cuticular lipids isolated from the housefly, Musca domestica. Melting temperatures (Tm) of surface lipids isolated from female houseflies decreased from 39.3 degrees C to 35.3 degrees C as the females attained sexual maturity and produced sex pheromone, whereas those prepared from males did not change with age. Lipids melted over a 10-25 degrees C temperature range, and their physical properties were a complex function of the properties of the component lipids. The Tm of total cuticular lipids was slightly below that of cuticular hydrocarbons (HC), the predominant lipid fraction. Hydrocarbons were further fractionated into saturated, unsaturated, and methyl-branched components. The order of decreasing Tm was total alkanes > total HCs > methyl-branched alkanes > alkenes. For 1-day-old flies, measured TmS of hydrocarbons were 1.3-5.5 degrees C lower than TmS calculated from a weighted average of TmS for saturated and unsaturated components. For 4-day-old flies, calculated TmS underestimated Tm by 11-14 degrees C.
我们研究了从家蝇（Musca domestica）分离出的表皮脂质的生物物理特性。随着雌性家蝇达到性成熟并分泌性信息素，从雌性家蝇分离出的表面脂质的熔点（Tm）从39.3摄氏度降至35.3摄氏度，而从雄性家蝇制备的脂质熔点则不随年龄变化。脂质在10至25摄氏度的温度范围内熔化，其物理性质是组成脂质性质的复杂函数。表皮总脂质的Tm略低于表皮烃类（HC），即主要的脂质组分。烃类进一步分为饱和、不饱和和甲基支链组分。Tm降低的顺序为：总烷烃>总烃类>甲基支链烷烃>烯烃。对于1日龄的家蝇，所测烃类的Tm比根据饱和与不饱和组分的Tm加权平均值计算出的Tm低1.3至5.5摄氏度。对于4日龄的家蝇，计算出的Tm比实际Tm低11至14摄氏度。
