For First Time, Scientists Create Mice with Cells from Two Males

For First Time, Scientists Create Mice with Cells from Two Males

For the first time, scientists have created baby mice with two fathers. They did this by turning mouse stem cells into female cells in a lab.

Stem cells are cells early in their development that can develop into any other kind of cell.

The result raises the distant possibility of doing the same for people. But experts say very few mouse embryos² were born alive. They add that no one knows if the same method would work in human stem cells.

Diana Laird is a stem cell and reproductive expert at the University of California, San Francisco. She was not involved with the research. She said the researchers developed a very smart method for changing male stem cells to female stem cells. She added, "It's an important step in both stem cell and reproductive biology."

Scientists described their work in a study published last week in the journal Nature.

First, the researchers took skin cells from the tails of male mice and changed them into a kind of stem cell called "induced pluripotent stem cells." These cells can develop into many different kinds of cells or tissues. Then, they turned the male mouse stem cells into female cells and produced functional³ egg cells. They did this through a process that involved growing the stem cells and treating them with a drug.

Finally, they fertilized⁴ those eggs and placed the embryos into female mice. About one percent of the embryos – 7 out of 630 – grew into live baby mice.

Katsuhiko Hayashi of Kyushu University and Osaka University in Japan led the research. He spoke⁵ with fellow scientists at the Third International Summit on Human Genome Editing earlier this month. He said the baby mice appear to grow normally and were able to become parents themselves in the usual way.

Jonathan Bayerl works with Laird. The two scientists said in an article published alongside the Nature study that the work "opens up new avenues in reproductive biology and fertility research" for animals and people. In the future, for example, it might be possible to reproduce endangered animals from a single male.

But they also raised several possible problems. The largest one is that the method is extremely inefficient⁶. They said it is unclear why such a small number of the embryos placed into the female mice survived. The reasons could be technical or biological. They also said it is too early to know if the method would work in human stem cells at all.

Laird added that scientists need to be careful of the mutations and mistakes that may be introduced in the method before using stem cells to make eggs.

The research is the latest to test new ways to create mouse embryos in the lab.

Last summer, scientists in California and Israel created mouse embryos from stem cells without the beginning cells needed for reproduction or uterus. Those embryos followed the development of natural mouse embryos up to eight and a half days after fertilization. Scientists said the success could be used in creating human embryos for research in the future.

Words in This Story

mouse – n. a very small animal that has a pointed⁸ nose and a long, thin tail

embryo¹ – n. a human or animal in the early stages of development before it is born or hatched

tail – n. the part of an animal's body that extends from the animal's back end

avenue – n. a way of achieving something or of reaching a goal

inefficient – adj. not capable of producing desired results without wasting materials, time, or energy

mutation⁷ – n. a change in the genes of a plant or animal that causes physical characteristics that are different from what is normal

1 embryo   

n.胚胎，萌芽的事物

参考例句：

• They are engaging in an embryo research.他们正在进行一项胚胎研究。
• The project was barely in embryo.该计划只是个雏形。

2 embryos   

n.晶胚；胚，胚胎( embryo的名词复数 )

参考例句：

• Somatic cells of angiosperms enter a regenerative phase and behave like embryos. 被子植物体细胞进入一个生殖阶段，而且其行为象胚。 来自辞典例句
• Evolution can explain why human embryos look like gilled fishes. 进化论能够解释为什么人类的胚胎看起来象除去了内脏的鱼一样。 来自辞典例句

3 functional   

adj.为实用而设计的，具备功能的，起作用的

参考例句：

• The telephone was out of order,but is functional now.电话刚才坏了，但现在可以用了。
• The furniture is not fancy,just functional.这些家具不是摆着好看的，只是为了实用。

4 Fertilized   

v.施肥( fertilize的过去式和过去分词 )

参考例句：

• The study of psychology has recently been widely cross-fertilized by new discoveries in genetics. 心理学研究最近从遗传学的新发现中受益匪浅。
• Flowers are often fertilized by bees as they gather nectar. 花常在蜜蜂采蜜时受粉。

5 spoke   

n.（车轮的）辐条；轮辐；破坏某人的计划；阻挠某人的行动 v.讲，谈（speak的过去式）；说；演说；从某种观点来说

参考例句：

• They sourced the spoke nuts from our company.他们的轮辐螺帽是从我们公司获得的。
• The spokes of a wheel are the bars that connect the outer ring to the centre.辐条是轮子上连接外圈与中心的条棒。

6 inefficient   

adj.效率低的，无效的

参考例句：

• The inefficient operation cost the firm a lot of money.低效率的运作使该公司损失了许多钱。
• Their communication systems are inefficient in the extreme.他们的通讯系统效率非常差。

7 mutation   

n.变化，变异，转变

参考例句：

• People who have this mutation need less sleep than others.有这种突变的人需要的睡眠比其他人少。
• So far the discussion has centered entirely around mutation in the strict sense.到目前为止，严格来讲，讨论完全集中于围绕突变问题上。

8 pointed   

adj.尖的，直截了当的

参考例句：

• He gave me a very sharp pointed pencil.他给我一支削得非常尖的铅笔。
• She wished to show Mrs.John Dashwood by this pointed invitation to her brother.她想通过对达茨伍德夫人提出直截了当的邀请向她的哥哥表示出来。