​Researchers Announce Successful Rhino Embryo Transfer

2024-02-08 11:45:00来源:网络

Researchers Announce Successful Rhino Embryo Transfer

研究人员宣布成功转移犀牛胚胎

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  By John Russell

  30 January 2024

  Scientists in Berlin announced recently the first successful embryo transfer in a white rhinoceros.

  The transfer, which occurred in a southern white rhinoceros, offers hope for saving the northern white rhino from completely dying off.

  Two kinds of white rhinoceros

  The white rhinoceros includes two different subspecies, the northern and the southern. The last male northern white rhino died in 2018. Only two female members of the subspecies remain. Neither of them can carry a baby.

  Southern white rhinos are more numerous.

  Researchers hope to use eggs and sperm from northern white rhinos to produce embryos that will be put into southern white rhino surrogate mothers.

  A surrogate is something that performs the duties of something else.

  To test the plan, scientists said they transferred the embryo of a southern white rhino into a surrogate southern white rhino mother at the Ol Pejeta Conservancy in Kenya on September 24, 2023.

  However, the research team only learned of the pregnancy after the surrogate mother died of a bacterial infection in November 2023. The embryo was discovered during an examination of the body after death.

  Even with the death, researchers found reasons to be hopeful.

  The international BioRescue team, a group backed by the German government, confirmed recently that the operation had produced a successful pregnancy of 70 days, with a well-developed 6.4-centimeter-long male embryo.

  "We achieved together something which was not believed to be possible," said Thomas Hildebrandt of the Leibniz Institute for Zoo and Wildlife Research.

  "That is really a milestone to allow us to produce northern white rhino calves in the next two, two and a half years," Hildebrandt said.

  Too late?

  The northern white rhinoceros subspecies has only two known examples left in the world. The Ol-Pejeta Conservancy in Kenya says that Najin, a 34-year-old, and her 23-year-old offspring, Fatu, both cannot naturally reproduce.

  In 2018, the last male white rhino, Sudan, was 45 when he was euthanized because of age-related problems. He was Najin's father. Scientists stored his semen and that of four other dead rhinos.

  Some conservation groups have argued that it is probably too late to save the northern white rhino using the method known as in vitro fertilization.

  The species once lived in Chad, Sudan, Uganda, Congo and Central African Republic, but human conflict has caused the creature to disappear. Critics say the efforts made to save the northern white rhino should instead go to save at-risk species that have a better chance to survive.

  About 20,000 southern white rhinos remain in Africa. That subspecies and another species, the black rhino, are increasing in number after illegal hunting nearly caused their disappearance.

  I'm John Russell.

  John Russell adapted this story from AP and Reuters report.

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  作者:约翰·罗素

  2024年1月30日

  柏林的科学家最近宣布了白犀牛中首次成功的胚胎转移。

  这次在南方白犀牛中进行的转移,为挽救北方白犀牛免于彻底灭绝提供了希望。

  有两种白犀牛。

  白犀牛包括两个不同的亚种,北方和南方。最后一只雄性北方白犀牛在2018年去世。这个亚种只剩下两只雌性成员。她们都不能生育。

  南方白犀牛数量较多。

  研究人员希望使用北方白犀牛的卵子和精子来产生胚胎,然后将这些胚胎放入南方白犀牛的代孕母亲体内。

  代孕是指代替其他事物执行职责的事物。

  为了测试这个计划,科学家们说他们在2023年9月24日在肯尼亚的奥尔佩杰塔保护区,将一只南方白犀牛的胚胎转移到了一只南方白犀牛的代孕母亲体内。

  然而,研究团队只有在代孕母亲在2023年11月因细菌感染死亡后,才得知她怀孕的消息。胚胎是在死后对尸体进行检查时发现的。

  即使发生了死亡,研究人员还是找到了希望。

  由德国政府支持的国际BioRescue团队最近确认,这次手术产生了一个成功的怀孕,怀孕期为70天,有一个发育良好的6.4厘米长的雄性胚胎。

  "我们共同实现了一些人认为不可能的事情,"莱布尼茨动物园和野生动物研究所的托马斯·希尔德布兰特说。

  "这真的是一个里程碑,让我们在接下来的两年、两年半内能够生产北方白犀牛的小牛,"希尔德布兰特说。

  太晚了吗?

  北方白犀牛亚种在世界上只剩下两个已知的例子。肯尼亚的奥尔-佩杰塔保护区说,34岁的纳金和她23岁的后代法图都不能自然繁殖。

  2018年,最后一只雄性白犀牛苏丹,因为年龄相关的问题被安乐死,当时他45岁。他是纳金的父亲。科学家保存了他和其他四只已经死亡的犀牛的精液。

  一些保护团体认为,使用被称为体外受精的方法来拯救北方白犀牛可能已经太晚了。

  这个物种曾经生活在乍得、苏丹、乌干达、刚果和中非共和国,但人类冲突导致这个生物消失。批评者说,为了拯救北方白犀牛所做的努力应该转向拯救有更好生存机会的濒危物种。

  在非洲,还剩下大约20,000只南方白犀牛。这个亚种和另一个物种,黑犀牛,数量正在增加,因为非法狩猎几乎导致它们消失。

  我是约翰·罗素。

  约翰·罗素根据美联社和路透社的报道改编了这个故事。

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  这个故事中的词汇

  transfer – v.将某物从一个地方移动到另一个地方

  subspecies – n.比物种小的一组相关的植物或动物

  achieve – v.做你试图做的事情

  milestone – n.某事物进步或发展的重要点

  euthanize – v.以人道的方式结束生命

  in vitro – adj.(科学)在实验室进行或在正常生物方法之外进行


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