Over the past four years, the ambitious BioRescue consortium has been tirelessly working to rescue the northern white rhino from the brink of extinction. Through cutting-edge assisted reproduction techniques, they have achieved remarkable progress, generating and preserving 29 northern white rhino embryos for future implantation into surrogate mothers.
In May 2023, during a scientific expedition in Kenya, a significant breakthrough was made as the team successfully collected 18 mature eggs from a female rhino named Fatu. These eggs were then expertly fertilized at the Avantea lab in Italy, resulting in the creation of five more embryos than ever before from a single egg collection. To promote genetic diversity, the embryos were produced using sperm from two different bulls.
Prior to this successful endeavor, the team faced challenges with fewer embryos generated in the previous collections of November 2022 and February 2023, yielding only two and zero embryos, respectively.
In addition to these advancements, the BioRescue team achieved another crucial milestone in their mission. They identified and selected two wild southern white rhino females as potential surrogate mothers, ensuring they were in good health and safely relocated to a secure enclosure. These southern white rhinos will play a pivotal role in supporting the breeding efforts for the endangered northern white rhinos.
To ensure the success of the project, the team also confirmed the continued sterility of the southern white rhino teaser bull, Ouwan. His role is essential as he indicates when a potential surrogate mother is ready for embryo transfer. To avoid unwanted pregnancies, it is crucial for the bull to remain sterilized.
Moving forward, the next critical steps for the BioRescue project involve performing embryo transfers with southern white rhino embryos. This will demonstrate the efficacy of the chosen transfer protocol. Once a successful pregnancy is achieved using this protocol, the team will utilize it for transferring the cryopreserved northern white rhino embryos, aiming to produce viable offspring as swiftly as possible. This ongoing effort represents a beacon of hope for the most endangered mammal species on Earth.