日前，PLoS ONE發(fā)表的一項(xiàng)最新的研究論文稱，在野生魚類中——確切地說(shuō)是游弋于澳大利亞大堡礁附近的珊瑚色藍(lán)點(diǎn)鱒魚中——發(fā)現(xiàn)了首批皮膚癌“患者”,。
這些鱒魚身上的損傷和黑斑，就像是人類患上了黑色素瘤,，只不過(guò)后者是長(zhǎng)有鱗片的版本而已,。至于它們是否會(huì)使鱒魚吃起來(lái)不安全，目前尚不明確,。
一群來(lái)自澳大利亞海洋科學(xué)研究所的海洋生物學(xué)家,，在大堡礁研究鯊魚時(shí)最早注意到了這些患病的鱒魚。隨后,，該研究團(tuán)隊(duì)通過(guò)在顯微鏡下檢測(cè)病變處的皮膚細(xì)胞驗(yàn)證了他們的推測(cè),。
科學(xué)家們還在實(shí)驗(yàn)室里喂養(yǎng)了一條劍尾魚和一條月光魚，以產(chǎn)生對(duì)紫外線更為敏感的后代并使其患上皮膚癌,。
研究發(fā)現(xiàn),，不同于正常的魚類皮膚細(xì)胞，這些病變細(xì)胞緊緊地聚集在一起,，并且在通常沒有黑色素的部位產(chǎn)生了黑色素,。更重要的是，野生鱒魚的病灶與實(shí)驗(yàn)室中劍尾魚和月光魚雜交所產(chǎn)生后代的病變相同,。
因此,，研究人員認(rèn)為，這三種生活于大堡礁的鱒魚很有可能正在罹患皮膚癌,。他們將該病歸咎于幾個(gè)因素,。首先，大堡礁直接位于臭氧層最大空洞的下方,，這意味著同地球上其他地方相比,，該地區(qū)實(shí)際上接受了更多的紫外線輻射。
同時(shí),，他們認(rèn)為,，這三種魚類彼此間可能出現(xiàn)了雜交現(xiàn)象,，導(dǎo)致某些基因的消失或者突變，從而使其后代更容易遭受紫外線誘導(dǎo)的皮膚癌的侵害,。（生物谷Bioon.com）
doi:10.1371/journal.pone.0041989
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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.
