Scientists have successfully performed the first embryo transfer in white rhinos, offering hope for the critically endangered northern white rhino species to be rescued from extinction.
Following the death of the final male northern white rhino, Sudan, in 2018, it seemed likely that the species would soon disappear. However, there are still two infertile female northern white rhinos, Fatu and Najin, who are currently being protected around the clock by armed guards at a conservation reserve in Kenya. Thanks to a recent scientific breakthrough, it is now possible that these mother and daughter rhinos may not be the only ones left of their kind.
A group of scientists from BioRescue, a consortium funded by the German government to prevent extinctions, have achieved the initial successful embryo transplants in southern white rhinos. This breakthrough could potentially lead to the use of the same technique for the more endangered northern white rhinos.
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. Although this technique is frequently utilized in humans, horses, and cows, it had never been attempted in rhinos until now.
The mother and father passed away due to a rare bacterial infection while the fetus was 70 days old. However, experts have confirmed that the pregnancy serves as evidence that the technique is effective.
According to Thomas Hildebrandt, director of the BioRescue project and a professor at the Leibniz Institute for Zoo and Wildlife Research, this method is crucial in the effort to preserve the northern white rhino.
“The Guardian was told by the individual that this small infant is evidence of all that was done – the sperm injection, fertilization process, storage in liquid nitrogen, and thawing process. These procedures had never been attempted before for rhinos, and there was a possibility of failure.”
According to him, the success of the procedure in rhinos was a significant achievement. In contrast, he added, “Humans are easy! We are dealing with a 2.5-ton mammal.”
In the coming months of May or June, scientists intend to insert the initial northern white rhino embryo. The embryos of the northern rhinos were generated utilizing sperm collected from two deceased males and eggs collected from Fatu. They will be carried by a surrogate southern white rhino in Kenya. Currently, only 30 embryos are left, preserved in liquid nitrogen at a temperature of -196C in Berlin, Germany and Cremona, Italy.
The embryo is inserted into the surrogate rhino through its anus. If the pregnancy lasts for 16 months and is successful, it would mark the first birth of a northern white rhino since 2000. This breakthrough could potentially lead to the protection and preservation of the Sumatran rhino, which has a population of only 40 in its natural habitat.
The scientists stated that they plan to conduct additional embryo transfers if the initial pregnancy is successful. This could result in up to six northern white rhino calves being born in a brief timeframe. It is crucial for the calves to interact with Fatu and Najin while they are still alive in order to learn the behavior of a northern white rhino.
According to Hildebrandt, even if multiple northern white rhino babies are delivered, they will not possess enough genetic variation to sustain a successful population. The 30 remaining northern white rhino embryos were all created using eggs from Fatu and sperm from two different males.
Researchers plan to utilize gene editing to enhance the genetic variety of future offspring by incorporating genetic material from museum samples, in the event of an increase in mammal births.
Hildebrandt explained that their team’s process involves retrieving genetic samples from the skulls and utilizing gene editing techniques to reintroduce them into the population. They intend to visit multiple museums that possess specimens of the northern white rhino, as this is more than just a scientific endeavor – their ultimate goal is to revive the species.
In 2021, it was declared that the number of southern white rhinos had risen for the first time since 2012, with a recorded increase from 15,942 to 16,803. However, there are still concerns about their future survival.
The director general of Kenya Wildlife Service, Erustus Kanga, expressed excitement about the progress made in protecting the subspecies.
The Kenya Wildlife Service is pleased to have been involved in this venture for the past 13 years, starting in 2009 when the northern white rhinos were relocated to Kenya. They are proud to be a part of the BioRescue consortium’s important efforts over the last four years.
“This marks a significant achievement in the conservation of the genetic lineage of the northern white rhino.”
The CEO of Ol Pejeta Conservancy, Justin Heath, stated that it was a significant achievement for conservationists. However, the news was bittersweet due to the loss of the surrogate and bull to a bacterial infection.
“I am proud to announce that the successful surrogate transfer of a rhino on Ol Pejeta Conservancy has resulted in the world’s first pregnancy. We are excited for the arrival of future rhino calves under the majestic Mount Kenya.”
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