红鳍笛鲷皮肤色素细胞组成、分布及类胡萝卜素含量分析

Analysis of Pigment Cells Composition,Distribution and Carotenoids Content in Skin of Lutjanus erythropterus

【目的】揭示红鳍笛鲷(Lutjanus erythropterus)红体色的分布特征及影响机制。【方法】利用色差仪分别测定背部、腹部和尾部皮肤的体色值,用形态学观察、石蜡切片、冰冻切片和透射电镜切片等方法分析色素细胞组成、分布和数量特征,并使用紫外分光光度法和液相色谱-质谱/质谱法研究类胡萝卜素和体色特征的关系。【结果与结论】红鳍笛鲷体表的红色素细胞显著多于黑色素细胞(P<0.001),且从背部向腹部逐渐减少,红体色受到黑色素细胞分布的影响;皮肤和视网膜是类胡萝卜素的主要沉积部位,皮肤中类胡萝卜素以脂肪酸结合的形式存在,其中红色类胡萝卜素主要有虾青素、角黄素和β-柠乌素等3种,虾青素和角黄素含量与红色素细胞数量呈正相关。建议在饲料中补充虾青素和角黄素以提升红色。

【Objective】To reveal the distribution characteristics of red coloration in crimson snapper(Lutjanus erythropterus)and its influential mechanism.【Method】The color values of the skin in dorsal,abdomen and tail regions were measured by colorimeter.And the composition,distribution and quantitative characteristics of the pigment cells were analyzed by morphological observation,paraffin section,frozen section and transmission electron microscope section.The relationship between carotenoids and body color was studied by UV spectrophotometry and liquid chromatography-mass spectrometry/mass spectrometry(LC-MS/MS).【Result and Conclusion】The erythrophores were significantly more than melanophores in the three parts of the skin,which gradually decreased from the back to the abdomen,and the red color was influenced by the distribution of melanophores;Carotenoids were mainly deposited in the skin and retina,and existed as carotenoid esters.Furthermore,three red carotenoids(astaxanthin,canthaxanthin andβ-citraurin)were present in the skin.The amount of astaxanthin,canthaxanthin was positively correlated with erythrophore counts.Dietary supplementation with astaxanthin and canthaxanthin can be used to enhance the red coloration.