经济学人:熊猫遗传学:熊猫的第二拇指(2)(在线收听) |
He and his colleagues noted parallel changes in the genes for three digestive enzymes whose job is to liberate two particular amino acids, lysine and arginine, from proteins. 他的团队发现三种消化酶基因相似的改变,这些消化酶的作用是从蛋白质中释放两种特殊的氨基酸,赖氨酸和精氨酸。 Both lysine and arginine are abundant in meat, but in short supply in bamboo. 肉类中富含赖氨酸和精氨酸,而在竹子中却很缺乏。
The team also noted parallel changes in four genes that encode proteins involved in the metabolism of two vitamins, A and B12, and of arachidonic acid, a lipid essential for bodily function. 该团队还注意到四种变化相同的基因,这些基因编码的蛋白质包括新陈代谢中所需的维生素A,维生素B12和机体功能必需的脂质-花生四烯酸。
All of these are scarce or non-existent in bamboo as well. 而这些在竹子中非常缺乏甚至不存在。
Exactly how the genetic changes seen alter the effectiveness of the proteins involved remains to be determined. 基因变化具体是如何改变所涉及蛋白质的有效性仍有待确定。
But the prediction would be that they enhance the availability of the nutrients in question. 但可预测的是,它们增强了讨论中的营养素的可利用性。
The upshotis that the two pandas do indeed seem to have similar genetics underlying their similar peculiarities. 结论是:基于两类熊猫的相似特性,它们确实有相似基因。
Such similarities are, admittedly, easier to find than different genetic routes to the same outcome would be. 诚然,这些相似之处比不同的基因路径更容易找到相同的结果。
But Dr Hu has established that, at least in the case of pandas, natural selection has often taken the same paths to arrive at the same outcomes. 但是胡博士已经确定,至少在熊猫中,自然选择通常以相同的途径达到相同的结果。 |
原文地址:http://www.tingroom.com/lesson/jjxrfyb/jjxrkj/457547.html |