白犀牛联合起来拯救北方濒临灭绝的犀牛

白犀牛联合起来拯救北方濒临灭绝的犀牛

While the world watches two southern white rhinos that could serve as surrogates for northern white rhinos, researchers are making progress behind the scenes creating viable embryos.

当全世界都在关注南方的两头白犀牛，它们可能成为北方白犀牛的代孕者时，研究人员却在幕后创造出了可存活的胚胎。

In July 2018, A southern white rhino named Victoria gave birth to a healthy male calf, marking the first successful birth from artificial insemination of a southern white rhino in North America.

2018年7月，一头名为维多利亚的南方白犀牛产下一头健康的雄性幼崽，这是北美第一头通过人工授精成功产下的南方白犀牛。

Photo: Tammy Spratt, photographer/San Diego Zoo Safari Park

Victoria is one of two southern white rhinos at San Diego Zoo Safari Park that were artificially inseminated in 2018, part of a long-term effort to save the northern white rhino from extinction. Although both mothers have been carrying southern white rhino babies, their pregnancies are part of a careful testing process for southern white rhinos to eventually serve as surrogate mothers of baby northern white rhinos. The other mother-to-be, Amani, is due in November or December.

维多利亚是圣地亚哥野生动物园2018年人工授精的两头南方白犀牛之一，这是拯救北方白犀牛免于灭绝的长期努力的一部分。尽管这两位母亲都怀上了南部白犀牛宝宝，但她们的怀孕是对南部白犀牛进行仔细测试的过程的一部分，最终将成为北部白犀牛宝宝的代孕妈妈。另一位准妈妈阿曼尼的预产期是11月或12月。

Only two northern white rhinos, a distant subspecies, are alive; both are female but neither can bear a calf. The last male northern white rhino, named Sudan, was euthanized in March 2018 at a preserve in Kenya due to age-related health problems.

只有两只北方白犀牛，一个遥远的亚种，还活着;它们都是雌性，但都不能生小牛。最后一头雄性北方白犀牛名叫苏丹，由于年龄相关的健康问题，于2018年3月在肯尼亚的一个保护区被安乐死。

Researchers hope that one day Victoria and Amani could serve as surrogate mothers, giving birth to a northern white rhino baby. They're optimistic a northern white calf could be born this way within 10 to 15 years, and the work could also be applied to other rhino species, including critically endangered Sumatran and Javan rhinos.

研究人员希望有一天维多利亚和阿曼尼能成为代孕妈妈，生下一个北方白犀牛宝宝。他们乐观地认为，在10到15年内，一头北方白犀牛将以这种方式出生，这项研究也可以应用于其他犀牛物种，包括濒临灭绝的苏门答腊和爪哇犀牛。

A breakthrough with embryos

胚胎研究取得突破

Researchers point out the calf in Victoria's ultrasound. (Photo: Tammy Spratt, photographer/San Diego Zoo Safari Park)

The zoo institute has the cells of 12 individual northern white rhinos stored at its "Frozen Zoo." Scientists hope to convert those preserved cells to stem cells, which could develop into sperm and eggs to be used to artificially inseminate the female southern white rhinos.

动物园研究所将12只北方白犀牛的细胞储存在“冷冻动物园”里。科学家们希望将这些保存下来的细胞转化为干细胞，这些干细胞可以发育成精子和卵子，用于人工授精南方白犀牛。

An international team of scientists made huge strides when they were able to harvest 10 eggs from the last two surviving female northern white rhinos, Najin and Fatu — who are currently living in a Kenyan national park under 24-hour guard. In late August, they revealed that seven of those eggs were successfully matured and artificially inseminated, according to a report from the Ol Pejeta Conservancy in Kenya where they live.

一个国际科学家团队取得了巨大的进步，他们从最后两只幸存的雌性北方白犀牛纳金和法图身上收获了10个卵子。这两只雌性北方白犀牛目前生活在肯尼亚的一个国家公园里，受到24小时的保护。据他们居住的肯尼亚奥佩杰塔自然保护协会(Ol Pejeta Conservancy)的一份报告显示，8月底，他们发现其中7个卵子已经成功成熟，并进行了人工授精。

Najin (left) and Fatu, the only two remaining northern white rhinos, graze together at Kenya's Ol Pejeta Conservancy in 2018. (Photo: Tony Karumba/AFP/Getty Images)

A study published in the Proceedings of The Royal Society B also offered hope that artificial insemination will be successful. Researchers analyzed DNA from living southern white rhinos and compared it with DNA from museum specimens of northern white rhinos. They discovered the two subspecies are more closely related than previously thought and crossbred for thousands of years after the species split.

发表在《英国皇家学会学报B》上的一项研究也带来了人工授精成功的希望。研究人员分析了现存南方白犀牛的DNA，并将其与博物馆里北方白犀牛标本的DNA进行了比较。他们发现，这两个亚种之间的亲缘关系比之前认为的更为密切，而且在物种分裂后的数千年里，它们一直在杂交。

"Everyone believed there was no hope for this subspecies," Hildebrandt told BBC News. "But with our knowledge now, we are very confident that this will work with northern white rhino eggs and that we will be able to produce a viable population."

“每个人都认为这个亚种没有希望了，”希尔德布兰特告诉BBC新闻。“但根据我们现在的知识，我们非常有信心，这将与北部白犀牛卵的工作，我们将能够产生一个可行的种群。”