读英语文章（鲸鱼拥有超强的抗癌能力）
Whales" cancer resistance "in their genes"
鲸鱼基因中的“抗癌能力”
Whales, dolphins and porpoises have two properties that should not in theory go together, they have a long lifespan for mammals and they tend to be resistant to cancer.
鲸鱼、海豚和鼠海豚有两种理论上不应该同时存在的特性，它们的寿命较长，而且往往对癌症有抵抗能力。
A new study suggests that the reason is written in their genes.
一项新的研究表明，这是由基因决定的。
In general, when a creature has more cells in its body, they are expected to be more vulnerable to random mutations that can develop into cancer.
一般来说，当一个生物体内的细胞越多，它们就越容易受到可能发展成癌症的随机突变的影响。
"Given this, we would expect that large and long-lived species, such as whales, have a higher rate of cancer than in small species," said lead author Daniela Tejada-Martinez at the Austral University of Chile.
“考虑到这一点，我们可以预期大型长寿物种，比如鲸鱼，比小型物种患癌症的几率更高，”智利南方大学的首席作者丹妮拉·特哈达-马丁内斯说。
So how to explain the longevity of the bowhead whale, which can reach 60 feet in length, weigh up to around 200,000 pounds (nearly 100 tonnes) and live for more than 200 years?
那么，如何解释北极露脊鲸的长寿呢?它身长可达60英尺，体重可达20万磅(近100吨)，寿命可达200多年。
"The way in which the different species throughout their evolutionary history managed to fight cancer remains a mystery," Tejada-Martinez told AFP.
特哈达-马丁内斯对法新社表示:“不同物种在进化史上是如何战胜癌症的，至今仍是个谜。”
This is known as Peto"s paradox, when some species do not have an incidence of cancer that correlates with their cell count.
这被称为皮托悖论，即某些物种的癌症发病率与它们的细胞数量无关。
To investigate this, researchers tracked the evolution of 1,077 tumor suppressor genes.
为了调查这个问题，研究人员追踪了1077个肿瘤抑制基因的进化。
The study, published in the journal Proceedings of the Royal Society B, found signs of positive genetic selection in key regulators of DNA-damage and the immune system.
这项发表在《英国皇家学会学报B辑》(Proceedings of The Royal Society B)上的研究发现，在DNA损伤和免疫系统的关键调节因子中存在积极基因选择的迹象。
The turnover rate for these tumor suppression genes was almost 2.4 times higher in cetaceans than other mammals.
这些肿瘤抑制基因在鲸类动物中的转换率几乎是其他哺乳动物的2.4倍。
Researchers also identified duplication of 11 genes linked to longevity.
研究人员还发现了11个与长寿相关的基因。
But the patterns of gene evolution varied by species.
但是基因进化的模式因物种而异。
Baleen whales, for example, had molecular variants in their tumor-suppressing genes and a fast turnover rate that may explain the evolution of their "gigantism and longevity," said Tejada-Martinez.
特哈达-马丁内斯说，例如，须鲸在它们的肿瘤抑制基因中有分子变异和快速的周转率，这可能可以解释它们“巨大和长寿”的进化。
The bottlenose dolphin, however, had the lowest number of gene copies among the cetaceans studied.
然而，在所有被研究的鲸类动物中，宽吻海豚的基因复制数最低。
Since this species is associated with an increased incidence of cancer, the authors hypothesized that this suggests a higher rate of tumor suppressor gene copies could mean a lower risk of developing cancer.
由于这种基因与癌症发病率的增加有关，作者推测，这表明肿瘤抑制基因复制率越高，患癌症的风险就越低。
"The link between evolutionary biology and medicine allows a more complete understanding of how the different forms of genetic variations contribute to cancer resistance and the aging evolution in cetaceans," said Tejada-Martinez.
特哈达-马丁内斯说:“进化生物学和医学之间的联系使我们能够更全面地了解不同形式的基因变异如何促进鲸类动物的抗癌和衰老进化。”
"The discovery of new molecular variants including additional copies of genes could be the key to reveal new biological pathways that could lead to the creation of innovative treatments for cancer and age-related diseases."
“新分子变异的发现，包括额外的基因拷贝，可能是揭示新的生物学途径的关键，这可能导致癌症和年龄相关疾病的创新治疗方法的创造。”