Oocyte collection and embryo creation in southern white rhinos

Date:
June 17, 2020
Source:
Forschungsverbund Berlin
Summary:
In order to prevent the extinction of species such as the northern
white rhino, experts are developing new methods and technologies
for conservation.



FULL STORY ==========================================================================
In order to prevent the extinction of species such as the northern
white rhino, the BioRescue consortium is developing new methods and technologies for conservation. An important part of this work is basic
research in cooperation with zoological institutions. This partnership
has enabled the BioRescue team to continue working even during the
Corona pandemic. On May 26, 2020, the team extracted oocytes from the
southern white rhino female "Makena" in Serengeti Park in Hodenhagen,
Germany, and then fertilized them in the Avantea laboratory in Italy to
create four viable embryos. This was the team's most successful procedure
of its kind and nourishes the hope that advanced assisted reproduction technologies (aART) are well established to ensure the survival of the
northern white rhino in the near future.


========================================================================== Problems with natural reproduction are often a major factor in the decline
of wildlife populations, both in the wild and in human care. Therefore, techniques and methods of assisted reproduction are of crucial importance
for science- based conservation. The northern white rhino is no longer
able to survive on its own as a species since both remaining individuals
are females. In order to perpetuate the species' existence, immature egg
cells (oocytes) were collected from them in the past, which were then fertilised in the laboratory with thawed sperm collected from already
deceased bulls and kept frozen. These embryos will be transferred at
some stage to southern white rhino surrogate mothers and could ensure
the birth of a northern white rhino calf.

Southern white rhinos in European zoos also have reproduction
problems. Basic research for complex assisted reproduction technologies
can therefore be carried out as a win-win situation for southern and
northern white rhinos. To achieve this, cooperation with zoological institutions is an essential component of the BioRescue Consortium. On
26 May 2020, Prof. Dr. Hildebrandt , the leader of this Consortium,
and his team extracted 12 oocytes from the seven-year-old southern white
rhino female "Makena" in the Serengeti Park in Hodenhagen, Germany. This
was made possible because a suitable partner for Makena could not be transported to the zoo because of the corona pandemic.

Subsequently, the extracted occytes were matured in the Avantea laboratory
in Italy and seven of them were successfully fertilised with sperm
from a southern rhino bull from Salzburg Zoo. Four embryos developed,
which are now preserved in liquid nitrogen. This is BioRescue's most
successful egg collection and embryo creation in white rhinos so far.

Owing to restrictions on international travel, the BioRescue team
had to postpone a procedure in Kenya planned for May. It will be
rescheduled as soon as circumstances permit. BioRescue is an international consortium of research institutions, zoological gardens and conservation organisations. Its goal is to develop advanced assisted reproduction technologies (aART) and stem cell- associated techniques (SCAT), and
to apply them as new science-based interventions for conservation. The consortium is led by Prof. Dr. Thomas Hildebrandt, head of the Department
of Reproduction Management at Leibniz-IZW.

Further consortium partners are the Max Delbru"ck Center for Molecular
Medicine (MDC), the AVANTEA Laboratory of Reproductive Technologies,
the Safari Park Dvur Kra'love', the Universita degli studi di Padua and
Kyushu University.

BioRescue is funded by the German Federal Ministry of Education and
Research (BMBF).

Statements Prof. Dr. Thomas Hildebrandt, head of the Department of
Reproduction Management at Leibniz-IZW and the BioRescue consortium:
"We are glad that we could restart with BioRescue project after the
COVID-19 lockdown. We have found a very competent partner in the Serengeti
Park Hodenhagen, so that we achieved our best result collection and
embryo production ever. Based on this outcome our optimism regarding a successful rescue of the practically extinct northern white rhinoceros has improved significantly." Dr. Fabrizio Sepe, owner and managing director
of Serengeti Park Hodenhagen: "Conservation is a central task for us. In
1996 our bull Kai in Namibia was the first European-born white rhino in
the world to be released into the wild.

Giving something back to nature was also a very moving moment for me personally. In this context I am even prouder today that we can make
a valuable contribution to the BioRescue project with our Makena. I am confident that with our joint efforts we can secure a long-term future
for many species on this planet!" Prof. Cesare Galli, Head of Avantea Laboratory: "We are pleased that international activities have resumed
after the pandemic and we were able to store additional embryos that will
be crucial to achieve our main milestone now i.e. the establishment of
a pregnancy after the transfer of a frozen embryo.

This will be crucial when we come to transfer the few and precious
NWR embryos that we have produced so far and will be producing
in the future. The laboratory procedures are now well established, reproducible. To achieve this milestone, we will need the support of the
rhino community as we do not know how long it will take to master this
final aspect of the technology." Jan Stejskal, Director of communication
and international projects at Safari Park Dvur Kra'love' and coordinator
of the international efforts to save the northern white rhino: "All the
methods and protocols that we now use in Kenya to save the northern white
rhino were developed thanks to a collaboration between scientists and
European zoos. The results from Hodenhagen are very promising and show
that research that helps animals in human care can be beneficial even
for saving species in their wild environment. We believe that experience
and knowledge gained through work with southern white rhino females in
European zoos will lead to a successful pregnancy with the pure northern
white rhino embryo in Kenya in the foreseeable future."

========================================================================== Story Source: Materials provided by Forschungsverbund_Berlin. Note:
Content may be edited for style and length.


==========================================================================


Link to news story: https://www.sciencedaily.com/releases/2020/06/200617091018.htm

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