Research Group 4: Reproduction Biology
Research Group 4: Reproduction Biology |
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Immunocontraception is a birth control method that uses the body's
immune response to block an indispensable step in the reproductive
process. It offers a humane means of controlling animal populations,
if traditional methods like hunting or poisoning are impossible
to apply.
The most studied immunocontraceptive method is the
use of zona pellucida proteins (ZP), which has been propagated since
its efficiency was demonstrated in feral mares. The application
of porcine ZP, however, failed in felid species because of an insufficient
immune response (Jewgenow et al., 2001). To increase the antigenicity
of ZP proteins, the use of synthetic peptides representing B-cell
epitopes are suggested. Furthermore, identifying unique epitopes
of the target species ensures a species-specifity, which is demanded
for contraceptive vaccine of feral or wildlife species.
Results/Publications:
Current research topics:
Interaction of the zona pellucida
trefoil domain with oviductin during passage of early embryos through
the oviduct. See also oviductin-project
If you are interested in our wild pig contraception draft please load down the pdf (in German)
Cooperation
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The Iberian Lynx (Lynx pardinus) is the only cat species worldwide listed Critically Endangered in the IUCN/SSC Red List (http://www.redlist.org/). Today the Iberian lynx remains in only two isolated populations located in the region of Andalusia and Castilla-La Mancha, Spain. The actual population size comprises approximately 200 animals in the wild. At the beginning of this century the establishment of an Ex situ conservation breeding program (http://lynxexsitu.es) was recognized as an essential part of the coordinated action plan to conserve this highly endangered species. In-situ efforts are mainly directed towards habitat preservation and restoration, decreasing non-natural causes of mortality and to raise social awareness for the plight of the Iberian lynx. In addition, the captive breeding program plans to maintain a breeding stock of 60 lynxes – a number which will allow for the maintenance of 85% of the lynxes´ genetic diversity during a 30 year period with reintroductions commencing in 2010.
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Figure: First litter of Iberian lynx born at the breeding Center 2005 in the Donana National Park, Spain (Photo ILCBC) |
The Eurasian lynx is considered to be a “model” species for study of reproductive traits and for developing techniques in assisted reproduction for the Iberian species, although its numbers in Europe are not high (about 8000 individuals; von Arx, 2004) and numbers in Russia have declined constantly over the last 20 years (25.000 animals in 2003). Thus, that the Eurasian lynx will be faced with the same problems as the Iberian might be a matter of time. In some parts of Eastern Europe (Poland) the genetic diversity of remained population is supposed to very low, whereas in Middle Europe including Germany reintroduction programs were started in protected areas.
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Figure: Sergey Naidenko at the field research station of the Institute of Ecology and Evolution, Moscow with an immobilized Eurasian lynx (photo: Jewgenow, IZW). The IZW performed reproductive health assessment on male and female captive Eurasian lynx in Moscow.
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This project combines efforts and knowledge of European teams with a broad experience in various fields of cats’ biology: Institute of Ecology and Evolution (IEE), Moscow (http://www.sevin.ru) unique colony of Eurasian lynx and other cat species; study on reproductive strategies and ontogenesis), Iberian Lynx Captive Breeding Center (http://lynxexsitu.es), and Institute for Zoo and Wildlife Research (IZW, Berlin, study of non-invasive hormones monitoring and reproduction management in wild animals).
Cooperation
Research group 1
Research group
2
Research group 5
Results/Publications
Current research topic
Pregnancy diagnosis based on specific placental signals in urine and feces. See also feto-maternal interactions
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Figure: The IZW (Katarina Jewgenow and Beate Braun) team is discussing the outcome of pregnancy test with Astrid Vargas (head of ILCBC, in the middle) during their stay in March 2009 at the El Acebuche breeding center, Donana NP.
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Figure: Witness® Relaxin tests were performed with bug ingested Iberian lynx blood plasma or highly concentrated urine samples (x 50). The positive lanes (arrows) are an indication for relaxin in the sample. |
Although the potential use of reproductive biotechnologies for
safeguarding endangered wildlife species is undoubted, practical
efforts have met with limited success. The most limiting factor
is the lack of abundant numbers of fertilizable oocytes. This problem
could be addressed by using the large source of oocytes available
from preantral and primordial follicles which comprise more
than 99% of ovarian oocytes. It has been estimated that there can
be 1000 - 75,000 follicles per ovary. If these gametes could be
collected and grown to maturity this would give a rich source of
genetic material.
The ability to use fresh and cryopreserved
ovaries, ovarian tissue, follicles and/or oocytes for reproductive
technologies is particularly important as it will allow the female
germ line of any animal, including those which suddenly die or undergo
spaying for medial reasons, to be utilized independent of time and
space. In this respect, ovaries of domestic cats which can be obtained
regularly from animal clinics can serve as a research tool to investigate
oocyte preservation and folliculogenesis.
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Results/Publications
Recent research topics:
Cryopreservation of cat ovarian tissue by slow and ultrafast freezing and investigation of viability of intraovarian primordial follicles by cytological, ultrastructural (link zur ELMI) and molecular methods.
Cooperation
Claus Yding Andersen,
Laboratory of Reproductive Biology, University Hospital of Copenhagen,
Rigshospitalet, Copenhagen, Denmark
research group 3
reseach group
5
All 37 species of the cat family (Felidae) except the domestic cat are endangered or threatened by extinction due to habitat destruction or poaching. The European Association of Zoos and Aquaria (EAZA) and the Institute for Zoo and Wildlife Research (IZW) conjointly evoke the European zoos to support a unique project to establish Assisted Reproductive Technologies (ART) for the felid family. ART comprise in vitro fertilisation, artificial insemination, embryo transfer, and cryopreservation of gametes. The long-term objective of this project is to establish a gamete bank including feline sperm, oocytes, embryos and gonadal tissue of diverse species for special breeding and research projects.
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In vitro fertilization techniques for endangered animals in captivity are associated with time-consuming transportation of gametes from the animal holder institutions to the lab. Cooperating zoos in our gametes rescue project for felids are spread all over Europe and shipping time of felid gametes to the IZW in case of castration or euthanasia ranges between 24 and 48h. Storage conditions for sperm cells that simulate transportation must be evaluated for their potential to preserve fertilization capacity and new ways of storage like freeze-drying should be traced.
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Most wild felids are endangered by habitat loss and poaching and often more individuals live in captivity than in the wild. For preserving genetic diversity their reproduction needs to be supported by artificial reproduction technology (ART). In vitro maturation (IVM) and in vitro fertilization (IVF) of oocytes as well as in vitro culturing (IVC) conditions for felid embryos have to be established and advanced. In order to improve in vitro techniques, embryonic quality and potency are evaluated by morphology, habitus as well as cleavage timing criteria. Besides, molecular characteristics as the relative mRNA abundance of specific selected genes important for preimplantative development are examined for their potency to serve as further markers. The findings may serve to design in vitro approaches as close as possible to the in vivo conditions to ensure embryo survival and healthy development.
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