The public zoo in San Diego, California and two private U.S. companies have successfully cloned a wild cow that's endangered in its native Java, Indonesia.
Two banteng clones were born recently to domestic cows in the midwestern state of Iowa. Zoo officials hope they'll be able to use this developing technology to help other endangered species. The two cloned bantengs were born at the Trans-Ova Corporation's research farm in Iowa on April first and third. The first clone had a birth weight of about 22 kilograms and is reportedly doing well. The second animal, which was born nine kilograms heavier, was euthanized a few days after its birth. Trans-ova spokesman Eric Woolson says officials are limiting human contact with the surviving calf in an effort to protect him from infection.
"For many endangered species, the first month is really a critical time period," he explained. "So basically we're giving these animals the best possible care that we can." The San Diego Zoo initially provided frozen cells from a banteng bull who had died 23 years ago, and worked with Trans-Ova and another firm, Advanced Cell Technologies of Massachusetts, to produce the genetic copies of the Asian ruminant. The wild cows are endangered in their native Java.
Zoo geneticist Oliver Ryder says researchers took fertilized eggs from a domestic cow and removed the nucleus.
"And then the nucleus that contained both parental and maternal genetic contributions from the banteng individual was inserted into the egg," said Mr. Ryder.
This was only the second time that cross-species cloning has been attempted. The first resulted in a birth three years ago, but the calf survived for only two days. Mr. Ryder points out that the genetic material for the Banteng clones came from a unique collection of animal tissue in San Diego. "We're in the room that holds the frozen zoo," he said.
Several oil-drum-size freezers line the walls of this tiny room.
"Its cold because even though these are great big thermos flasks, its 200 degrees below zero, centigrade in there," explains Mr. Ryder.
The freezers contain samples of a menagerie of ordinary and rare animals, from monkeys to Gray whales. Mr. Ryder lifts the lid on one flask to expose a thick fog of super cooled air.
A fan lifts the vapor away, exposing tall metal racks. Mr. Ryder puts on a thick insulated glove, grabs a handle and lifts one up.
The thousands of tiny vials inside the freezer contain tissue from about 6,000 animals, representing 400 distinct species. The samples were collected at the zoo and represent animals from countries all over the world. The zoo says future cloning efforts could help revitalize a number of endangered species, but Mr. Ryder notes that doesn't mean the zoo will begin bringing back extinct animals.
"Cloning technology that is available right now requires access to living celles and their nuclei and there aren't any of those from any extinct organism that I'm aware of," he said.
Zoo officials say they're pursuing the cloning of animals like the banteng in an effort to boost the fragile gene pools of threatened species. Even so, Mr. Ryder says the zoo's primary mission remains the protection of rare species in the wild, not populating their exhibits. University of California San Diego researcher Ted Friedman worries that cloning successes could breed complacency about threats to wildlife habitats around the world.
"If we sort of justify much of that continued habitat destruction by saying it doesn't much matter because we can bring back these species when and if we want," said Mr. Friedman. "That strikes me as a dangerous rational for not solving the real underlying problem and that is how we manage our environment." According to Mr. Freidman, scientific research also shows that cloned animals are not as hardy as their naturally born counterparts. Zoo officials say they're not sure how long the remaining clone will live, but they hope the Banteng reaches breeding age. If things go well in Iowa, the clone could be brought to San Diego in a couple of weeks.
