Unless humans intervene, the northern white rhinos will soon vanish.
Fortunately for this dwindling subspecies, a group of scientists performing research at a renowned animal reproduction lab in Italy are attempting to stave off the subspecies’ extinction. As there are no males left to mate with the two remaining females, an embryo must be created in a laboratory.
The scientists had the foresight to acquire 300 milliliters of northern white rhino sperm from three males before they died, and they recently used the valuable sperm to create the first-ever rhino embryo in a lab. Their research was published Wednesday in the journal Nature Communications.
But, this embryo is not made of pure northern white rhino genes. It’s a hybrid.
The researchers didn’t have any northern white rhino eggs, so they instead used eggs from the rhino’s closely related subspecies, the southern white rhino.
While this hybrid embryo doesn’t fulfill the goal of creating pure northern white offspring, it does prove that scientists can successfully combine rhino sperm and eggs in vitro — or outside of the body — in a lab environment.
“The main goal is to have pure northern white rhinos,” Thomas Hildebrandt, the scientist who headed the research, said in a call with reporters.
Creating the initial seed of a rhino, or any animal, in the confines of test tubes or cultured dishes doesn’t reduce its natural authenticity. If rhinos are ever produced, they’ll be the real thing.
“The fact that it’s made in a laboratory doesn’t mean it’s a fake embryo, Cesare Galli, a study coauthor and director at the Italian Avantea lab where the embryo was created, added.
And it appears their hybrid embryo turned out quite well.
“You never can say it’s 100 percent viable until you get offspring, but they did good work,” Carol Keefer, who researches embryonic development and stem cells at the University of Maryland and had no involvement in the study, said in an interview.
“The pictures of the embryos are gorgeous,” she added, referring to the images of the well-formed embryos the researchers included in their paper.
But that doesn’t mean there aren’t challenges ahead for this research.
First, the researchers need eggs from the two female northern white rhino’s remaining.
These eggs live deep inside the rhinos, but the researchers have a “patented nearly two-meter long technical device” they use to safely extract eggs from the sedated animals. They also need permission from the Kenyan government to take the eggs, Hildebrandt added.
But just having the eggs won’t be enough. To produce a healthy, viable population, the researchers will also need to employ sophisticated methods to diversify the rhino genes, so they’re not sickly, inbred creatures.
“They really need a bigger pool of females,” said Keefer.”
This can be accomplished by using embryonic stem cells, which are “master cells” capable of being differentiated into other cells with diverse genes. Keefer notes this is a more “futuristic process,” but one that the right scientists can perform.
The researchers said that they intended to use related stem cell technologies to take other frozen northern white rhino cells, such as skin cells, and turn them into stem cells that can be manipulated into both sperm and eggs.
There’s also the matter of taking these embryos and actually creating a viable rhino from them, which is no easy task.
Once a pure northern white rhino embryo has been created, it then has to be implanted into a southern white rhino surrogate mother, and she has to successfully give birth.
However, the two remaining northern females aren’t able to properly reproduce, said Hildebrandt.
“I would say they’ve got a good chance of embryo transfer [implanting the embryo],” said Keefer, citing the group’s past experience with implanting embryos into southern white rhinos.
Many rhino embryos will need to be implanted in surrogate mothers to produce a large, viable population.
“If they bring back two or four, that’s not a genetically viable population,” Kenneth Lacovara, the dean of the School of Earth and Environment at Rowan University who had no role in the study, said in an interview. “The whole Noah’s Ark story doesn’t really pan out.”
And once the animals are born, they’ll need protected refuges to live in, as they’ll grow much sought-after horns.
“There’s still lots of challenges,” said Keefer.
Even so, Hildebrandt and company hope to accomplish a complete northern white rhino embryo transplant in about a year, he said.
Is it worth the money and effort?
The northern white rhino’s counterparts, the southern whites, are doing quite well — for rhinos — with a population of some 20,000 individuals.
This, some leading conservationists argue, is where conservation efforts should be focused — on existing viable populations — not those with two inbred females.
Protecting rhinos from poaching and providing for safe habitat is already trying and expensive.
But it appears many scientists and conservationists say this laboratory method is still worth a shot — regardless of the hurdles.
The northern white rhino’s demise wasn’t precipitated by their evolutionary undoing. Rather, we’ve killed them for their horns, which today are associated with mythical health benefits derived from drinking the ground-up horn powder.
“They didn’t fail on their own — they got slaughtered wholesale,” said Lacovara. “I think we have a moral obligation to try [these lab methods].”
“The northern white rhino didn’t fail because of evolution,” said Hildebrandt. “It failed because it’s not bullet-proof.”