VOA科学技术2023 新研究发现鲸鱼体型巨大的基因（在线收听）

New Study Finds Genes Linked to Whales’ Huge Size

新研究发现鲸鱼体型巨大的基因

Scientists have wondered long on the mystery of how whales got so big. A new study suggests some answers.

科学家们对鲸鱼是如何变得如此巨大的奥秘一直很好奇。一项新的研究提出了一些答案。

Whales are ocean animals. The fin, bowhead, gray, humpback and sperm whales are the largest animals living today. In fact, the blue whale is the largest animal known to have ever existed, bigger than any dinosaur.

鲸鱼是海洋动物。长须鲸、弓头鲸、灰鲸、座头鲸和抹香鲸是当今最大的动物。事实上，蓝鲸是已知有史以来最大的动物，比任何恐龙都大。

The recent study by researchers in Brazil found that four genes appear to play a big part in whales' huge size, a condition known as gigantism. The researchers said the four genes appear to have produced great size while easing the problems linked with it, such as cancer risk and lower reproductive ability.

巴西研究人员最近的一项研究发现，四种基因似乎对鲸鱼的巨大体型起到了重要作用，这种情况被称为巨人症。研究人员表示，这四个基因似乎产生了巨大的体积，同时缓解了与之相关的问题，如癌症风险和生殖能力低下。

Whales are part of the ocean animal family called Cetaceans, which includes dolphins and porpoises. Scientists think the family developed 50 million years ago from animals like wolves, but is also related to today's cows, pigs, sheep and similar animals.

鲸鱼是鲸目海洋动物家族的一部分，包括海豚和海豚。科学家认为这个家族在5000万年前由狼等动物发展而来，但也与今天的牛、猪、羊和类似动物有关。

Mariana Nery, a genetics expert with the University of Campinas (UNICAMP) in Brazil, was a lead writer of the report. It appeared in the publication Scientific Reports. Nery said her team has done the first study of gigantism in whales at the molecular level. She said, "Body size is a complex result of many genes, pathways, and physical and ecological processes."

巴西坎皮纳斯大学（UNICAMP）的遗传学专家玛丽安娜·内里是该报告的主要撰写人。它出现在出版物《科学报告》中。Nery说，她的团队在分子水平上首次对鲸鱼的巨人症进行了研究。她说：“体型是许多基因、途径、物理和生态过程的复杂结果。”

The study examined seven kinds of whales that grow longer than 10 meters. Six of them are toothless animals. Instead, they have structures called baleen in their mouths that catch very small animals. The seventh species studied was the sperm whale, which has large teeth to feed on giant squid and ocean animals.

这项研究考察了七种生长超过10米的鲸鱼。其中六只是没有牙齿的动物。相反，它们的嘴里有一种叫做须鲸的结构，可以捕捉非常小的动物。研究的第七个物种是抹香鲸，它有巨大的牙齿，可以吃巨型鱿鱼和海洋动物。

The whales can reach huge sizes. Humpback and right whales can reach 15 meters in length; the sperm and bowhead whales, 18 meters; the fin whale can reach 24 meters, and the biggest, the blue whale, has been measured at 30 meters.

鲸鱼可以达到巨大的体型。座头鲸和露脊鲸的长度可达15米；抹香鲸和弓头鲸，18米；长须鲸的身长可达24米，最大的蓝鲸的身段为30米。

The researchers studied several genes linked to increased body size in other animals. They found four genes that appeared to be important in the development of whales.

研究人员研究了几种与其他动物体型增大有关的基因。他们发现了四种似乎对鲸鱼的发育很重要的基因。

One of the genes is GHSR. It is involved in releasing growth hormone from the pituitary gland, a part of the body that releases important chemicals. Growth hormone can cause hunger and it can control metabolism and the growth of fat. The gene also controls cell division.

其中一个基因是GHSR。它参与从垂体释放生长激素，垂体是身体释放重要化学物质的一部分。生长激素可以引起饥饿，它可以控制新陈代谢和脂肪的生长。该基因还控制细胞分裂。

A second gene is called IGFBP7. This gene is involved in cell growth and division. There is evidence that this gene acts to suppress cancer in many parts of the body including the prostate, breasts, lungs, colon and rectum.

第二个基因叫做IGFBP7。该基因参与细胞生长和分裂。有证据表明，这种基因可以抑制身体许多部位的癌症，包括前列腺、乳房、肺部、结肠和直肠。

NCAPG is a gene associated with growth in humans, horses, cattle, pigs and chickens. It can cause size and weight gain and affects the lives of cells.

NCAPG是一种与人、马、牛、猪和鸡的生长相关的基因。它会导致体型和体重增加，并影响细胞的寿命。

The gene PLAG1 is associated with body growth in cows, pigs and sheep. It is involved in the growth of embryos and cell survival.

PLAG1基因与牛、猪和羊的身体生长有关。它参与胚胎的生长和细胞的存活。

The study also suggests that the genes such as GHSR and IGFBP7, which are linked to huge size, might also control cell development and suppress cancer. Huge size in nature is tied to shorter lifespans. But huge whales live long lives. The humpback whale can reach 50 years of age. The blue whale can reach 90 and, the study noted, the bowhead whale is the longest-lived mammal known, reaching 200 years of age.

这项研究还表明，GHSR和IGFBP7等与巨大尺寸相关的基因也可能控制细胞发育和抑制癌症。自然界巨大的体型与较短的寿命有关。但巨大的鲸鱼寿命很长。座头鲸的年龄可达50岁。蓝鲸可以达到90岁，研究表明，弓头鲸是已知寿命最长的哺乳动物，年龄达到200岁。

Felipe Andre Silva was lead writer of the study. He worked on the research while earning his master's degree in genetics and molecular biology.

费利佩·安德烈·席尔瓦是这项研究的主要作者。他在获得遗传学和分子生物学硕士学位的同时从事这项研究。

He said gigantism in whales appeared relatively recently, around 5 million years ago. "Before that there were animals with large sizes...but these were exceptions, and most cetaceans did not exceed 10 meters in length," he said.

他说，鲸鱼的巨人症是最近才出现的，大约在500万年前。他说：“在此之前，有体型较大的动物……但这些都是例外，大多数鲸目动物的长度都不超过10米。”。

Silva told Reuters news agency: "Gigantism may bring some advantages such as a lower chance of being preyed upon and a greater change of obtaining food."

席尔瓦告诉路透社：“巨人主义可能会带来一些好处，比如被捕食的几率更低，获取食物的方式也会发生更大的变化。”

Nery said a lot can be learned about the development, or evolution, of whales over long periods of time. She said, "These animals can teach us a lot about the evolutionary process itself." And whales remain popular and interesting to many people and gain a lot of attention. Nery added, "The evolution of cetaceans is a fantastic story..."

内里说，关于鲸鱼在长时间内的发展或进化，我们可以学到很多东西。她说，“这些动物可以教会我们很多关于进化过程本身的知识。”鲸鱼仍然受到许多人的欢迎和兴趣，并获得了很多关注。内里补充道，“鲸目动物的进化是一个奇妙的故事……”

Words in This Story

hormone –v. a substance produced by the body that influences growth, development and how organs work

激素–身体产生的影响生长、发育和器官工作的物质

metabolism –v. the processes essential for life by which the complex substances in the cells of living things are built up or broken down

新陈代谢–生物细胞中复杂物质的形成或分解过程

exceed –v. to become greater or bigger than something

超过–变得比某物更大

advantage –n. a desirable or good quality

优势–令人满意的或良好的品质

prey –v. to seize and eat something hunted

猎物–抓住并吃掉猎物

obtain –v. to get or gain something through effort

获取–通过努力获得某物

fantastic –adj. extremely good, usual or strange

太棒了--非常好，不寻常或奇怪