Biotechnicians want to use cloning to save endangered species, but they are having only limited success. Critics say that the push toward a new era of wildlife conservation trivializes extinction and funding would be better spent on preserving animal habitats.
A number of times each week, Martha Gómez creates new life. Today, she has set out to produce a South African black-footed cat. Using a razor-thin hollow needle under a microscope, the veterinarian injects a body cell from the endangered species into an enucleated egg cell taken from a house cat. Then she applies an electric current.
“Nine volts of alternating current for five microseconds, then 21 volts of direct current for 35 microseconds,” says Gómez. Zap! The egg cell rapidly flexes from the electric surges. It bubbles inside the cell. Then everything is calm.
“I will check in half an hour if the cells have fused properly,” says the researcher from the Audubon Center for Research of Endangered Species in New Orleans. The very next day, the cloned embryos will be implanted into the uterus of a common domestic house cat, which will serve as a surrogate mother for a foreign species.
Biotechnicians like Gómez are hoping for a new era of wildlife conservation. In a bid to save endangered species, they tear down biological barriers and create embryos that contain cell material from two different species of mammals. Iberian lynxes, tigers, Ethiopian wolves and panda bears could all soon be carried to term by related surrogate mothers, and thus saved for future generations.
“Interspecies cloning is an amazing tool to ensure that an endangered species carries on,” says Gómez. “We can’t wait until those species have disappeared.”
No Limits
But the researcher remains optimistic. She hopes that she will soon be able to transform body cells from her wildcats into pluripotent stem cells. Cells of this type could considerably simplify the cloning process because they can be used to create any type of body cell and can be easily multiplied. Other researchers have already succeeded in producing such stem cells from snow leopards and northern white rhinoceroses, which are both endangered species.
There are in fact virtually no limits to the creative experimentation of today’s biotechnicians. Chinese researchers have fused body cells from panda bears with eggs cells taken from rabbits. But the resulting embryos died shortly thereafter — in the uteruses of house cats. Meanwhile, Japanese researchers have implanted skin cells from an unborn baby sei whale in enucleated egg cells taken from cattle and pigs.
Other Japanese scientists are even trying to clone the woolly mammoth. Three years ago, cell nuclei from these hairy, tusked ice-age beasts were discovered in mammoth legs that have been frozen in the permafrost of Northeast Siberia for the past 15,000 years.
In the laboratory, a team led by geneticist Akira Iritani injected cell nuclei from the prehistoric animal into enucleated egg cells from mice. The cell constructs only survived for a few hours, but Iritani remains optimistic that an elephant surrogate mother will soon bring to term the first mammoth clone.
Spiegel has the full article
