日前，PLoS ONE发表的一项最新的研究论文称，在野生鱼类中——确切地说是游弋于澳大利亚大堡礁附近的珊瑚色蓝点鳟鱼中——发现了首批皮肤癌“患者”。
这些鳟鱼身上的损伤和黑斑，就像是人类患上了黑色素瘤，只不过后者是长有鳞片的版本而已。至于它们是否会使鳟鱼吃起来不安全，目前尚不明确。
一群来自澳大利亚海洋科学研究所的海洋生物学家，在大堡礁研究鲨鱼时最早注意到了这些患病的鳟鱼。随后，该研究团队通过在显微镜下检测病变处的皮肤细胞验证了他们的推测。
科学家们还在实验室里喂养了一条剑尾鱼和一条月光鱼，以产生对紫外线更为敏感的后代并使其患上皮肤癌。
研究发现，不同于正常的鱼类皮肤细胞，这些病变细胞紧紧地聚集在一起，并且在通常没有黑色素的部位产生了黑色素。更重要的是，野生鳟鱼的病灶与实验室中剑尾鱼和月光鱼杂交所产生后代的病变相同。
因此，研究人员认为，这三种生活于大堡礁的鳟鱼很有可能正在罹患皮肤癌。他们将该病归咎于几个因素。首先，大堡礁直接位于臭氧层最大空洞的下方，这意味着同地球上其他地方相比，该地区实际上接受了更多的紫外线辐射。
同时，他们认为，这三种鱼类彼此间可能出现了杂交现象，导致某些基因的消失或者突变，从而使其后代更容易遭受紫外线诱导的皮肤癌的侵害。（生物谷Bioon.com）
doi:10.1371/journal.pone.0041989
PMC:
PMID:
Evidence of Melanoma in Wild Marine Fish Populations
Michael Sweet1*, Nigel Kirkham2, Mark Bendall1, Leanne Currey3, John Bythell1,4, Michelle Heupel5,6
The increase in reports of novel diseases in a wide range of ecosystems, both terrestrial and marine, has been linked to many factors including exposure to novel pathogens and changes in the global climate. Prevalence of skin cancer in particular has been found to be increasing in humans, but has not been reported in wild fish before. Here we report extensive melanosis and melanoma (skin cancer) in wild populations of an iconic, commercially-important marine fish, the coral trout Plectropomus leopardus. The syndrome reported here has strong similarities to previous studies associated with UV induced melanomas in the well-established laboratory fish model Xiphophorus. Relatively high prevalence rates of this syndrome (15%) were recorded at two offshore sites in the Great Barrier Reef Marine Park (GBRMP). In the absence of microbial pathogens and given the strong similarities to the UV-induced melanomas, we conclude that the likely cause was environmental exposure to UV radiation. Further studies are needed to establish the large scale distribution of the syndrome and confirm that the lesions reported here are the same as the melanoma in Xiphophorus, by assessing mutation of the EGFR gene, Xmrk. Furthermore, research on the potential links of this syndrome to increases in UV radiation from stratospheric ozone depletion needs to be completed.
