你吃什么就是什么，至少你会变成与食物相同的颜色。
据美国《科学》杂志在线新闻报道，火烈鸟是红色的，那是因为它们吃虾。即便是人类，如果吃了太多的胡萝卜或番茄，皮肤也会显现出橙色。造成这一结果的原因便是色素，例如类胡萝卜素，然而科学家如今发现至少有一种动物不需要吃下这些色素便能够变色。
实际上，一种名为蚜虫的小昆虫(如上图)在它们的进化过程中从一种菌类中获得了分泌类胡萝卜素所需的基因。这使得蚜虫成为第一种已知能够产生自己的类胡萝卜素的动物。研究人员在5月7日出版的《科学》杂志上报告了这一发现。（生物谷Bioon.com）
生物谷推荐原文出处：
Science DOI: 10.1126/science.1187113
Lateral Transfer of Genes from Fungi Underlies Carotenoid Production in Aphids
Nancy A. Moran1,* and Tyler Jarvik2
Carotenoids are colored compounds produced by plants, fungi, and microorganisms and are required in the diet of most animals for oxidation control or light detection. Pea aphids display a red-green color polymorphism, which influences their susceptibility to natural enemies, and the carotenoid torulene occurs only in red individuals. Unexpectedly, we found that the aphid genome itself encodes multiple enzymes for carotenoid biosynthesis. Phylogenetic analyses show that these aphid genes are derived from fungal genes, which have been integrated into the genome and duplicated. Red individuals have a 30-kilobase region, encoding a single carotenoid desaturase that is absent from green individuals. A mutation causing an amino acid replacement in this desaturase results in loss of torulene and of red body color. Thus, aphids are animals that make their own carotenoids.
1 Department of Ecology and Evolutionary Biology, 1041 East Lowell Street, University of Arizona, Tucson, AZ 85721, USA.
2 Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, USA.
