VOA慢速英语听力：干细胞用于建立胚胎模型以研究人类早期发育 Stem Cells Used to Create Embryo Models to Study Early Human Development
Scientists say they have successfully created embryo models designed to support research on early human development.
科学家们表示，他们成功地创建了胚胎模型，旨在支持对人类早期发育进行研究。
The models are made from stem cells – simple cells in the body that can develop into one of many specialized cells. Researchers say the embryo models cannot grow into babies. But they are meant to be complete enough to provide information about what might be going on in the embryo during a pregnancy.
这些模型是由干细胞制成的——身体中可以发展为许多特化细胞之一的简单细胞。研究人员表示，胚胎模型无法发展成婴儿。但它们应该足够完整，能够提供关于妊娠期间胚胎内部发生的情况的信息。
The use of embryo models permits scientists to carry out research without the ethical concerns linked to experiments using real embryos.
使用胚胎模型使科学家能够进行研究，而不会引发使用真实胚胎进行实验所涉及的伦理问题。
Several groups are working on the research. Teams from the United States and England shared their work in two studies that recently appeared in the publication Nature. Other scientists in Israel and China published studies on their work earlier this month. Those studies, however, have not yet been examined by a wider community of scientists.
有几个团队正在进行这项研究。来自美国和英国的团队在最近发表在《自然》杂志上的两项研究中分享了他们的工作。以色列和中国的其他科学家本月早些时候也发表了他们的研究。然而，这些研究尚未被更广泛的科学界审查。
Insoo Hyun is an ethicist and director of life sciences at Boston’s Museum of Science. He is also a member of the Center for Bioethics at Harvard Medical School.
Insoo Hyun是波士顿科学博物馆的伦理学家和生命科学部主任。他也是哈佛医学院生物伦理中心的成员。
Hyun told The Associated Press that past research has centered on a process that creates “pre-embryos” designed to behave like real embryos. But the latest creations model an embryo after it has reached the uterus. Real human embryos can be extremely hard to see at that point in the process because they attach themselves deep into the uterus.
Hyun告诉美联社，过去的研究集中在一种能够表现得像真正胚胎的“前胚胎”过程。但是最新的创建是在胚胎进入子宫后进行的模拟。真正的人类胚胎在这个过程中在子宫深处依附，因此极难观察到。
Each team’s models differ in how complete they are, Hyun said. For these kinds of models, scientists use a kind of stem cell that is able to develop into many different kinds of cells or tissues in the body. They can be formed from embryos or reprogrammed from adult tissues.
Hyun说，每个团队的模型在完整性上都有所不同。对于这些模型，科学家使用一种能够发展成身体内许多不同种类的细胞或组织的干细胞。它们可以由胚胎形成，也可以通过重新编程成人组织形成。
The writers of several studies described models that look similar to human embryos nine to 14 days after fertilization.
几项研究的作者描述了在受精后9至14天看起来与人类胚胎相似的模型。
Berna Sozen studies developmental stem cell biology at Yale University in Connecticut. She told The Associated Press, “If we can experimentally model this period, then we can finally start asking questions about how human development happens in those very early stages that are normally hidden within the body of the mother.”
Berna Sozen在康涅狄格州的耶鲁大学研究发育干细胞生物学。她告诉美联社：“如果我们能够实验性地模拟这个时期，那么我们终于可以开始探索关于人类发育在那些通常隐藏在母体内的早期阶段是如何发生的问题。”
Sozen added that scientists should be able to use the models to study embryonic failure, developmental disorders and pregnancy loss. Currently, scientists do not understand a lot about how those things happen, she said.
Sozen补充说，科学家应该能够使用这些模型研究胚胎发育失败、发育障碍和妊娠损失。她说，目前科学家对这些事情发生的具体原因了解得不多。
Another study was led by Magdalena Zernicka-Goetz, an expert in stem cell biology at the California Institute of Technology and the University of Cambridge in England. She said the model her group worked with appears similar to embryo development up to 14 days from fertilization.
另一项研究由加州理工学院和剑桥大学的干细胞生物学专家Magdalena Zernicka-Goetz领导。她说，她的团队所使用的模型在受精后14天内的胚胎发育阶段与真实情况相似。
The researchers say that model contains embryonic tissues and other tissues that can produce structures surrounding the embryo, such as the placenta and yolk material. The placenta is a structure that develops in pregnancy and attaches to the uterine wall.
研究人员表示，这个模型包含了胚胎组织和其他可以产生包围胚胎的结构的组织，比如胎盘和卵黄物质。胎盘是在妊娠期间发育并附着在子宫壁上的结构。
In the future, Zernicka-Goetz said researchers could use human embryo models to explore the effects of the environment and chemicals on early human development.
Zernicka-Goetz表示，未来，研究人员可以使用人类胚胎模型来探索环境和化学物质对早期人类发育的影响。
Yale University’s Sozen said scientists could also test drugs on embryo models and combine them with germs in experiments that currently cannot be done on pregnant individuals.
耶鲁大学的Sozen表示，科学家还可以在胚胎模型上测试药物，并将其与细菌结合进行实验，而这些实验目前无法在妊娠个体上进行。
I'm Bryan Lynn.
我是Bryan Lynn。
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Words in This Story
ethical – adj. relating to what is right or wrong
uterus – n. (medical) a term for the organ in a woman that holds the baby during pregnancy; womb
