Tuesday, August 16, 2011

Harvesting ovaries, testes from dead wild animals: CCMB develops embryos from ovaries of dead endangered animal

Syed Akbar
Hyderabad, Aug 12: Ever wondered that a dead animal could give life to young ones. Scientists at the city-based Centre for Cellular and Molecular Biology have developed a major technique that could help generate young animals using the eggs and sperm of dead endangered or wild animals.
The CCMB’s technique will also help protect endangered or wild animals from possible extinction by perpetuating their generation. It involves harvesting of eggs and sperm from dead wild animals and cryopreservation for use in future to generate stem cells and propagate endangered species through cloning.
As endangered animals face the threat of extinction, harvesting of eggs and sperm from the dead ones is a major step forward in conserving scores of rare wildlife species for future generations. The CCMB team has not only obtained the egg cells (oocytes) from the ovaries of the dead animals, but also successfully fertilised them in laboratory to produce embryos.
"Our research is quite unique as we are utilising testes and ovaries of dead endangered animals, which otherwise would have gone waste. Using them we have produced embryos. But we could not move to the next step of transferring the embryos from the laboratory to the animal womb for want of permission. We have successfully demonstrated that ovaries and testes of even the dead animals can be used to produce their offspring at a later date," Dr S Shivaji, CCMB scientist incharge of Laboratory for Conservation of Endangered Species (LaCONES).
The oocytes would have implications in conservation of endangered animals since they can be cryopreserved. These oocytes could be used to generate embryos, which in turn could be useful to make young ones by embryo transfer. The embryos could also serve as a source for stem cells, while embryonic cells could also be used for nuclear transfer to generate young ones by cloning, Dr Shivaji said.
The CCMB scientists involved in the research project were Dr Brahmasani Sambasiva Rao, Dr Yelisetti Uma Mahesh, Uthanda Raman Lakshmikantan, Komjeti Suman and Katari Venu Charan, besides Dr Shivaji. Oocytes rescued from spotted deer and black buck have been cryopreserved at LaCONES. An ovary may yield as many as 30 eggs depending on the age of the dead animal.
"The ability to rescue gametes from endangered or wildlife species and to subsequently produce viable embryos holds tremendous potential as a means to increase the population size of endangered or wildlife species," Dr Shivaji said adding that its difficult to obtain oocytes from live animals as it is an invasive process for which the government may not give permission.
Application of reproductive biotechnologies for the preservation of endangered mammalian species is limited by several factors such as the lack of availability of species-specific biological material required for a better understanding of the fundamental biology of the male and female gametes.
"It is in this context that rescue of gametes from wild or endangered animals that have died unexpectedly is a worthwhile research tool for understanding the fundamental physiology of the species concerned and also for development of species-specific protocols for application of new emerging assisted reproductive technologies in endangered species," Dr Shivaji pointed out.

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