The operation is part of the standard protocol developed at the Audubon Center for Research of Endangered Species, or ACRES, which does some of the most advanced genetics work with cats in the world. ACRES has invented several cutting-edge techniques to preserve endangered cats, employing in vitro fertilization, cryopreservation, interspecies cloning, and other methods.

The small team at ACRES has made many headlines for its breakthroughs in the world of cat science. In 2008, ACRES created the first fluorescent cat: "Mr Green Genes," a cloned ginger tabby that glows green under ultraviolet light, demonstrating how a genetic "marker" such as fluorescence could be used to indicate the presence of genes for diseases, such as cystic fibrosis, which could then be targeted for gene therapy.

Most of ACRES’ feline efforts are concentrated on endangered-species cloning, however, which is why the scientists wanted Junebug’s eggs.

"Every species of non-domestic cat is under some threat."

ACRES specializes in interspecies embryo transfer, a procedure in which an endangered wildcat embryo is implanted into a common domestic cat mother. In 1999, ACRES produced an African wildcat kitten named Jazz, the first test-tube kitty born using this method. In 2003, researchers cloned Jazz to produce Ditteaux, officially the world’s first cloned African wildcat. In 2005, Ditteaux mated with another clone that gave birth to eight kittens, setting another record: the first time two cloned mammals bred naturally.

The center also produced the first cloned sand cat and caracal kittens, as well as the first black-footed wildcat kittens conceived in vitro and born to a domestic cat mother.

Although these lesser-known wildcats may be more common than the dangerously rare Bengal tiger, these feline species all fall on the endangered spectrum according to the global nonprofit International Union for Conservation of Nature and Natural Resources.

Habitat loss, poaching, and interbreeding with domestic cats has thinned their numbers. "Not all of them are classified as endangered," Dr. Pope says. "But they’re all considered threatened, or at least vulnerable. As far as I know, every species of non-domestic cat is under some threat."

The African wildcat is the grandfather of the household tabby and looks much the same. The rusty-spotted cat is tiny, sandy-colored, with spots like a leopard. The black-footed cat is also small, spotted, and ferocious. ACRES is working with these small cats because their embryos can be implanted into the uterus of a domestic cat, although the center has produced big-cat embryos as well.

The argument for preserving these relatively obscure species is obvious, although there is some disagreement as to whether it is worth the expense. ACRES says it has not calculated the cost of producing a cloned wildcat, but the price tag for cloning a pet cat — a much less complicated procedure — is in the mid-six figures.

"We human beings are colonizing the space of the animals, and we are destroying them because we are destroying the environment, and we are destroying the animals directly," says Dr. Martha Gomez, another senior scientist who handles most of the cloning and stem cell work. "We want the children and the future generations to be able to enjoy what we enjoy."

However, cloning as a method of conservation has its critics. The procedure has around a 5 percent success rate even for familiar animals that don’t involve an interspecies transfer; it’s even harder when transplanting wild embryos into domestic cats. The process for interspecies cloning is extremely inefficient, and the reasons are still not well understood. ACRES researchers feel lucky if they implant 42 embryos and get one kitten. Dr. Gomez and her colleagues have been trying to clone a black-footed cat for two years, producing pregnancies but no births. They’re still not sure why.

"The story of cloning endangered animals is one of a few high-profile successes and many, many failures."

ACRES has also been slogging away at this for more than 10 years, and is still nowhere near producing enough cats to jump-start the wild population — most cats stay at the center or are transferred to zoos. Cloning, as the technology stands today, is "unlikely" to help threatened species, according to a recent article in Scientific American. "To date, the story of cloning endangered animals is one of a few high-profile successes and many, many failures," writes Ferris Jabr.

In her two previous donations, Junebug had produced 72 eggs and 42 eggs. This time, though, the eggs were all immature and unusable. Dr. Pope wasn’t sure why, but the operation had been a bust. He managed to get 19 eggs from a second donor, which were shuffled over to Dr. Gomez; she injected them with rusty-spotted cat DNA and pulsed them with an electric current in order to fuse the genetic ingredients, which will be plugged into a donor cat.

Dr. Gomez, Dr. Pope, and their colleagues are now working on refining the cloning process, cloning rarer cats, and producing stem cells that will improve the cloning process. Cloning is just one "tool" in the conservation kit, they say. But it’s a valuable one, considering no other technique can bring an animal back from the dead.

"We are so inefficient at what we do, and there is so much more work to be done," Dr. Pope says. "But it does make you realize the potential is there, and it can and it will be done in the future, more and more of it. I firmly believe that."