Labbe C, Maisse G, Müller K, Zachowski A, Kaushik S, Loir M
Laboratoire de Physiologie des Poissons, INRA, Rennes, France.
Lipids. 1995 Jan;30(1):23-33. doi: 10.1007/BF02537038.
The effect of a long-term adaptation of rainbow trout to 8 and 18 degrees C combined with a corn oil- or a fish oil-supplemented diet on the characteristics of the spermatozoan plasma membrane was investigated. The experiment lasted up to 22 mon during which spermatozoa were collected from the mature males. Spermatozoan plasma membranes were isolated by nitrogen cavitation, and the cholesterol content, phospholipid composition and fatty acid pattern were investigated. Membrane viscosity was assessed on whole cells by electron spin resonance using spin-labeled phospholipids. Neither diet nor rearing temperature influenced the cholesterol content of the plasma membrane nor the phospholipid class distribution. The rearing temperature of the broodstock only slightly affected the phospholipid fatty acids. A minor decrease in 18:0 and increase in monounsaturated fatty acids was observed for the cold-adapted fish. These modifications were not sufficient to affect membrane fluidity, and we conclude that trout spermatozoa do not display any homeoviscous adaptations in these conditions. On the contrary, the dietary fatty acid intake greatly modified the fatty acid profile of plasma membrane phospholipids. The fish oil-fed trout displayed a much higher n-3/n-6 fatty acid ratio than did the corn oil-fed ones, but the 22:6n-3 levels remained unchanged. Modifications in plasma membrane composition by the diet were obtained although neither of the two diets was deficient in essential fatty acids. The enrichment in n-3 fatty acids, however, did not affect plasma membrane fluidity which was unchanged by the diets.
研究了虹鳟长期适应8℃和18℃环境，并分别投喂玉米油或鱼油补充饲料对精子质膜特性的影响。实验持续了22个月，在此期间从成熟雄性虹鳟中采集精子。通过氮空化法分离精子质膜，并研究其胆固醇含量、磷脂组成和脂肪酸模式。使用自旋标记磷脂通过电子自旋共振对全细胞的膜粘度进行评估。饲料和饲养温度均未影响质膜的胆固醇含量或磷脂类分布。亲鱼的饲养温度仅对磷脂脂肪酸有轻微影响。对于适应低温的鱼，观察到18:0略有下降，单不饱和脂肪酸略有增加。这些变化不足以影响膜流动性，我们得出结论，在这些条件下，虹鳟精子不会表现出任何同粘适应性。相反，饲料中的脂肪酸摄入量极大地改变了质膜磷脂的脂肪酸谱。投喂鱼油的虹鳟比投喂玉米油的虹鳟具有更高的n-3/n-6脂肪酸比值，但22:6n-3水平保持不变。尽管两种饲料均不缺乏必需脂肪酸，但饲料仍改变了质膜组成。然而，n-3脂肪酸的富集并未影响质膜流动性，饲料对其没有改变作用。
