Scientists have successfully performed the first embryo transfer in white rhinos, potentially saving the critically endangered northern white rhino species from extinction.
Following the death of the last male northern white rhino, Sudan, in 2018, the extinction of the species seemed inevitable. With only two infertile female northern white rhinos, Fatu and Najin, remaining, they are now being heavily guarded around the clock at a conservation reserve in Kenya. However, a recent scientific breakthrough suggests that these two individuals may not be the final representatives of their species.
A group of scientists from BioRescue, a consortium supported by the German government with the goal of preventing extinctions, has achieved the first successful embryo transfers in southern white rhinos. This breakthrough opens up the possibility of using the technique for the more endangered northern white rhinos as well.
In September of 2023, researchers implanted two southern white rhino embryos into surrogate mothers at the Ol Pejeta Conservancy in Kenya, leading to a successful pregnancy. Though this technique is often utilized in humans, horses, and cows, it had never been attempted with rhinos until now.
The parents passed away due to a unique bacterial infection while the unborn child was 70 days old. However, experts state that the successful pregnancy serves as evidence for the effectiveness of the technique.
According to Professor Thomas Hildebrandt, the leader of the BioRescue project and a faculty member at the Leibniz Institute for Zoo and Wildlife Research, this method is crucial in the effort to preserve the northern white rhino.
He expressed to the Guardian that this small infant is evidence of everything. The process of injecting sperm, fertilizing, preserving with liquid nitrogen, and thawing had never been attempted before with rhinos. Failure was a possibility at every step.
According to him, the successful implementation of the process in rhinos was a significant achievement. In contrast, he remarked, “Humans are easy! We are dealing with a mammal weighing two-and-a-half tons.”
In the coming months, researchers aim to implant the initial embryo of a northern white rhinoceros. These embryos were formed using sperm from two deceased male rhinos and eggs from Fatu, and will be carried by a surrogate southern white rhinoceros in Kenya. Currently, there are only 30 embryos remaining, preserved in liquid nitrogen at extremely low temperatures in Berlin, Germany and Cremona, Italy.
The embryo is inserted into the surrogate rhino through its rectum. If the 16-month gestation is a success, it would mark the first birth of a northern white rhino since 2000. This breakthrough could also lead to the protection and preservation of the Sumatran rhino, which currently has a population of only 40 in their natural habitat.
The researchers stated that they would conduct additional embryo transfers if the initial pregnancy appeared to be progressing successfully. This could potentially result in up to six northern white rhino calves being born within a brief timeframe. The scientists emphasized the importance of the calves interacting with Fatu and Najin while they are still living, in order to learn how to behave as northern white rhinos.
According to Hildebrandt, even if multiple northern white rhino babies are born, they will not have enough genetic variation to create a sustainable population. The 30 remaining northern white rhino embryos are all the result of eggs from Fatu and sperm from two males.
Scientists plan to utilize gene editing to enhance the genetic variety of future offspring by incorporating genetic material from museum specimens in the event of a larger number of mammal births.
Hildebrandt explained that their team searches for genetic material at skull sites, which they then utilize through gene editing to reintroduce into the population. They intend to visit various museums that possess samples of northern white rhino specimens in order to achieve their goal of reviving the species, as it is not simply a scientific endeavor but also a genuine desire to restore its existence.
In 2021, it was reported that the population of southern white rhinos had grown for the first time since 2012, going from 15,942 to 16,803. However, there are still concerns about their future sustainability.
The director general of Kenya Wildlife Service, Erustus Kanga, expressed excitement about the progress made in protecting the subspecies.
The Kenya Wildlife Service is happy to have been involved in this journey for 13 years, starting in 2009 when the northern white rhinos were brought to Kenya. They are also proud to be a part of the BioRescue consortium’s efforts over the past four years.
“This marks a significant achievement in safeguarding the genetic lineage of the northern white rhino.”
The CEO of Ol Pejeta Conservancy, Justin Heath, expressed that it was a significant achievement for conservation efforts, but also a sad moment due to the loss of the surrogate and bull to a bacterial infection.
“We are incredibly proud to announce that the first successful surrogate transfer in a rhino resulted in a pregnancy at Ol Pejeta Conservancy. We eagerly anticipate the birth of future rhino calves through the use of surrogacy in the beautiful landscape of Mount Kenya.”
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Source: theguardian.com
