科学美国人60秒 SSS 染色体来打击冒牌鱼子酱（在线收听）

Chromosomes Combat Counterfeit Caviar 染色体来打击冒牌鱼子酱

Caviar is one of the world's priciest foods: it can cost thousands of dollars a pound. And caviar from the beluga sturgeon is the most exclusive of all. But even experts have a hard time telling the eggs from two different species apart by appearance alone.

鱼子酱是世界上最昂贵的食物之一：一磅鱼子酱可能卖到数千美元。所有鱼子酱中白鲸鲟产的鱼子酱是最独特的。但是，即使是专家也很难仅凭外表就区分出两个不同鱼种的鱼子。

\So scientists came up with a method that more than meets the eye: a genetic test that identifies variations in nuclear DNA that are unique to the beluga, and its cousin, the sterlet. The test can differentiate roe of those two species from that of eight other species of sturgeon.

因此，科学家们想出了一个比视觉区分更好的方法：通过一种基因测试，识别白鲸鲟和其近亲小体鲟体内特殊的核基因的不同之处。该测试可以从其他8种鲟鱼品种中区分出这两种鱼的鱼卵。

And the best part, given caviar's premium price? The test requires just a single egg. The study is in the journal Scientific Reports.

该测试最大的优点是给鱼子酱定最高价?它仅仅需要一个鱼卵。这项研究发表于《科学报告》杂志。

The researchers say that by definitively identifying the real stuff, the test could prop up its high price. But this effort is not just of interest to the one percenters: genetic verification could also be used for conservation. Belugas are critically endangered. And since they hybridize with other sturgeon species, conservationists need to make sure that farm-raised fish they plan to reintroduce into the wild are the real thing. And not just a cheap lookalike.

研究人员表示，通过明确识别真材实料，该测试可以保持鱼子酱较高的价格。但是这一成就的贡献并不仅限于此一项益处：基因验证也可以被用于物种保护。白鲸鲟目前已濒临灭绝。既然它们能与其他鲟鱼物种杂交，那么环保人士需要确认他们打算放生野外的那些人工养殖的鱼种是货真价实的，而非仅是长得很像的山寨货。