Articles — Borneo Rhino Alliance
The seemingly “disastrous” story of the world’s most endangered mammal – the northern white rhino – could be rewritten by IVF, scientists claim.
They used the method to produce rhino embryos with sperm from two dead males.
The embryos were made using eggs from a closely related sub-species, but the scientists say the method could save the northern white rhino.
One of the team said he hoped a baby that’s fully northern white rhino would be born “within three years”.
This could provide a way of “rescuing valuable genes” from a sub-species that is already functionally extinct; the last male northern white rhino, named Sudan, died earlier this year at the age of 45.
Only two females now remain, but the researchers who carried out this project say their carefully-developed method of assisted reproduction could work with eggs harvested from those two precious animals.
How do you carry out rhino IVF?
In the journal Nature Communications, Prof Thomas Hildebrandt, from the Leibniz Institute for Zoo and Wildlife Research in Berlin, and his international team of colleagues, described the complexities of safely extracting an egg, or oocyte, from a two-tonne female rhino.
“You can’t reach the ovaries by hand, so we developed a special device,” Prof Hildebrandt explained to BBC News. “We used ultrasound to very precisely inject a needle into [the area of the ovary that releases] eggs.”
This was done while the female southern white rhino was under general anaesthetic, but the process is still very risky. Very close to the ovaries, Prof Hildebrandt explained, is a “huge artery” that if punctured would probably cause the rhino to bleed to death.
But once viable eggs were safely preserved, the team then had the challenge of fertilising them with sperm from male northern white rhinos – animals that died several years ago. They injected each egg with the sperm and used pulses of electrical current to stimulate the egg and sperm to fuse.
The result – viable embryos containing genetic material from a sub-species that is already functionally extinct.
“Everyone believed there was no hope for this sub-species,” said Prof Hildebrandt. “But with our knowledge now, we are very confident that this will work with northern white rhino eggs and that we will be able to produce a viable population.”
Could this bring back the northern white rhino?
These researchers think so, and others around the world who have been involved in efforts to save the northern white rhino say it is an important step.
But Dr Terri Roth, from Cincinnati Zoo, said the team’s suggestion that they would have a “new baby on the ground” within three years was “optimistic”.
“Embryo transfer [into a surrogate mother] in rhinos is in its infancy and has not yet been successful in any rhino species,” Dr Roth told BBC News.
“And there are just two female northern white rhinos alive today, so acquiring white rhino [eggs] will be challenging and their number will be limited. Any embryos produced would likely need to be cryopreserved (or frozen) until a surrogate could be set up.”
Why are there so few northern white rhinos left?
As Dr Roth explained, poaching is the primary threat facing all rhino species.
“The most effective way to save rhinos from extinction is to stop the poaching, however, that has proven difficult,” she told BBC News.
“In the late 1990s, even the wild northern white rhino had a chance to recover from low numbers until civil unrest broke out in the DRC and the rhinos were all killed.”
Loss of habitat is the other primary threat to rhinos, and conservationists say that governmental protection of parks and reserves is now essential.
“The proper legislation must be passed, the resources to enforce the regulations must be provided and the law must be upheld,” said Dr Roth, who has worked in rhino conservation for more than two decades.
“It is important that we learn from the plight of the northern white rhino and we make sure what happened to it does not happen to other endangered species.
“As impressive as science can be, we should not reach a point where these hi-tech approaches are the only source of hope for rescuing genes of valuable individuals, sub-species or entire species.”
Read the full BBC News article by Victoria Gill, Science reporter
DNA of northern white rhino — of which only two remain — mixed with that of close subspecies in a bid towards growing population using surrogates.
Fatu, one of the last two northern white rhinos, lives in Ol Pejeta Conservancy in Kenya.Credit: Nichole Sobecki/The Washington Post/Getty
Researchers have created hybrid rhino embryos as part of a ‘Hail-Mary’ attempt to rescue the northern white rhinoceros from all but certain extinction.
The embryos — which have now been frozen — contain DNA from northern white rhinos (Ceratotherium simum cottoni) and a close relative subspecies and could be implanted into surrogates to yield animals that are a mix of both. The work is reported in a Nature Communications paper published on 4 July1.
The research “is an impressive step forward for the whole field”, says stem-cell biologist Jeanne Loring, at the Scripps Research Institute in La Jolla, California. Her team hopes to use stem-cell technology to repopulate the rhinos.
A victim to poaching, the northern white rhino population is now down to only two females, making it the planet’s most endangered mammal. Earlier this year, Sudan, the last male of the subspecies, died of age-related disease (although his sperm has been preserved). His daughter Najin and her daughter, Fatu, live in Ol Pejeta Conservancy in Kenya. Najin has leg injuries that prevent her from becoming pregnant, and Fatu has fertility problems that prevent embryos from implanting into the womb.
Innovation versus extinction
Extinction of the northern white rhino would seem inevitable. However, a team led by Cesare Galli, a veterinarian and embryologist at Avantea, a biotechnology laboratory in Cremona, Italy, may have given the animal a second chance. Galli and his colleagues have developed a technique to extract eggs from female rhinos and fertilize them to generate viable embryos potentially capable of becoming animals.
Rather than test the procedure — which involves a risky anaesthetic — on Najin and Fatu, the researchers collected eggs from 12 southern white rhinos (Ceratotherium simum simum), a closely related subspecies whose numbers stand at around 20,000 across southern Africa.
The hybrid embryos were created with eggs collected from southern white rhinos and northern white rhino sperm.Credit: T. B. Hildebrandt et al./Nat. Commun.
Of 13 eggs injected with sperm from a now-deceased northern white rhino, four developed into blastocysts, or early embryos. These ‘hybrid’ blastocysts, which contain genes from both subspecies, can be frozen and later implantated into a surrogate to produce hybrid offspring. These hybrids could ensure that some of the northern white rhino DNA would be preserved.
The researchers injected 17 other eggs with sperm from a southern white rhino, to produce three ‘pure’ southern white rhino blastocysts.
To test the health of the blastocysts, the team generated stem-cell lines from two of the pure embryos. These showed all the signs of healthy embryonic stem cells, suggesting that the embryos from which they were generated would be viable once implanted.
Expand and diversify
The next step will be to harvest eggs from Najin and Fatu, fertilize them with northern white rhino sperm and implant the resulting embryos in a southern white surrogate — with an ultimate goal of having the first northern white rhino born within three years.
However, the offspring of this effort would lack the genetic diversity to sustain a healthy wild population of northern white rhinos, says Galli. A better, but more challenging, avenue is to use frozen tissue from a wider pool of northern white rhinos to generate stem cells that have the capacity to develop into eggs and sperm (see ‘Saving the Northern White Rhino’).
In 2011, Loring and her colleagues produced such cells, called induced pluripotent stem (iPS) cells, from Fatu’s skin2. Since then, Loring and her team have created 4 more iPS cell lines from northern white rhino tissue stored at San Diego Zoo Institute for Conservation Research in California.
In May, the researchers showed that this tissue — which comes from 12 male and female rhinos — contains enough genetic diversity to help save these giant animals3. “We expect to have cells that look like sperm and eggs in a year,” says Loring, “but there are still many challenges ahead.”
Humans versus nature
“It would be fantastic to see the northern white rhino back in its natural habitat,” says Stuart Pimm, a conservation biologist at Duke University in Durham, North Carolina. However, he is concerned that the underlying cause of the rhinos’ near-extinction has not been dealt with.
“Let’s celebrate this endeavour, but keep it in perspective,” Pimm says. “We still live in a world in which we have lost an enormous number of rhinos to poaching, and if we have any chance of putting their descendants back into the wild, we’ll have to prevent them from being killed the moment they’re released.”
SAN DIEGO – Victoria, a southern white rhino at the San Diego Zoo Safari Park, is pregnant. It’s an event of vital importance for a program to bring back her nearly extinct kin, the northern white rhino.
The developing baby is also a southern white rhino, conceived on March 22 through artificial insemination. The pregnancy is a dress rehearsal for the ultimate goal of creating more northern white rhinos, grown from embryos made from stem cells.
The lengthy rhino gestation period means the baby isn’t due until the summer of 2019. A failure would mean more work needs to be done, or that the female is infertile.
Only two northern white rhinos are alive today, both females. The last male, Sudan, died in March in a Kenya preserve. Another white rhino, Nola, died in November 2015 at the Safari Park. She was one of four alive at that time.
Credit: AP PHOTO
Victoria and five other female southern white rhinos at the Safari Park’s Nikita Khan Rhino Rescue Center have been conditioned for years to willingly accept the most intimate handling, such as ultrasound examination of their reproductive tracts.
Jeanne Loring, a stem cell scientist at The Scripps Research Institute, has worked on this project with the zoo for years. She expressed delight in the news.
“That’s awesome,” Loring said from Germany. “It’s an amazing feat. This is a milestone.”
Much of the rhino reproductive system hasn’t been studied before, she said. So the zoo and allied researchers like Loring have had to invent the technology as they go along.
View the related video here.
The project’s roots go back decades to a dream inspired by Oliver Ryder, a geneticist at San Diego Zoo Global, the zoo’s conservation arm.
Ryder suggested deep-freezing tissue from endangered animals, in the hope that future technology could recreate whole animals from these cells. He established a cryobanked collection of tissue from these animals, known as the “Frozen Zoo.”
The technology to put these cells to use finally arrived in 2007. Japanese scientist Shinya Yamanaka demonstrated that adult mammalian cells can be turned into artificial embryonic stem cells. He shared a Nobel Prize in 2012 for his discovery.
Loring is leading a separate project to use the cells to treat Parkinson’s disease. These induced pluripotent stem cells, as they are called, are to be created from the patients themselves. They will be matured into brain cells of the type destroyed in Parkinson’s, then implanted into the patient’s brains.
The rhino project is even more complicated. Thawed cryopreserved tissue will be converted into the artificial embryonic stem cells, then matured into egg and sperm cells. These will be united by in vitro fertilization to create an embryo. This is what will be implanted into the southern white rhino surrogate mothers.
Loring and Ryder are co-authors of a recent study describing how stem cells were produced from four northern white rhinos with a method they say is superior. Unlike earlier methods, it doesn’t use viruses to deliver genes that help convert the cells. So the cells created have a healthier genetic profile.
The study, which has yet to be published, can be found at j.mp/rhinostem.
The Safari Park says the work may be applicable for other rhino species, including the critically endangered Sumatran and Javan rhinos.
Distributed by Tribune Content Agency
This article appeared in VC Star on 18 May 2018. Read the original online article here.
The little-known and smallest member of the rhinoceros family, the Sumatran rhinoceros, is critically endangered. Today between 30 and 100 are isolated on the islands of Sumatra and Borneo in Southeast Asia. In a new study, researchers urge conservationists to translocate the two island groups–representing two subspecies of the Sumatran rhino–and to create a cell bank to preserve the genetic diversity uncovered by this work.
“It is heartbreaking as a geneticist to recommend that two subspecies, which are probably as different as humans were from the Neanderthals, should be combined into a single conservation unit,” said Al Roca, a professor of animal sciences in the College of Agricultural, Consumer and Environmental Sciences and the Carl R. Woese Institute for Genomic Biology at the University of Illinois.
The Sumatran rhino is the smallest of the remaining rhino species, but it is critically endangered — with 100 or fewer left in the wild today. Photo credit: Terri Roth
Published in the Journal of Heredity, the study analyzed 13 samples taken from zoos and the wild as well as 26 museum specimens to reveal differences in the species’ mitochondrial DNA, the small proportion of the genome that is passed down only from mothers to their offspring.
The study exposed 17 distinct mitochondrial haplotypes, a group of genes inherited from one parent, that can be used to trace a species’ migrations and distribution across thousands of years. The mitochondrial DNA also confirmed the classification of three subspecies of Sumatran rhinos: D. s. lasiotis (likely extinct), D. s. harrissoni, and D. s. sumatrensis.
In the wild, Sumatran Rhinos are solitary creatures, only coming together to breed. In such few numbers, it is increasingly difficult for them to find each other in their mountainous habitat. What’s more, if they are not able to mate, females develop reproductive diseases that prevent them from successfully breeding.
“My strongest recommendation is that they are brought into breeding centers as soon as possible because they aren’t going to survive in the wild in such low numbers,” Roca said. “A population of 10 individuals loses 5 percent of their genetic diversity each generation, which they cannot spare.”
“Unfortunately, at this point, we have to act quickly and risk losing unique genetic lineages in order to save a whole species,” said first author Jessica Brandt, now a professor of biology at Marian University.
This genetic erosion can be prevented, or slowed, by combining the remaining rhinos to create a larger population. A century of captive breeding efforts have yielded few babies, but recent successes suggest ex situ breeding facilities could help save this species from the brink of extinction–the result of poaching and habitat loss due to legal and illegal logging for desirable hardwoods.
To ensure the long-term genetic health of the species, the authors implore conservationists to preserve the genomes of every living Sumatran rhino. In the future, preserved cell lines could be used to create artificial gametes, to reverse the effects of inbreeding and harmful mutations.
“We may one day be able to use stored cells to bring back what was once lost, reversing the effects of inbreeding, drift, and our own folly,” Roca said. “Because they are at such low numbers, every single living Sumatran rhino is genetically very valuable, and preserving cells with genetic material from each surviving individual is of paramount importance.”
Read the original article here.
This work was made possible by the United State Fish and Wildlife Service Rhinoceros and Tiger Conservation Fund, the International Rhino Foundation, the World Wildlife Fund, the National Science and Engineering Research Council (Canada), and ACES Office of International Program.
The paper “Genetic structure and diversity among historic and modern populations of the Sumatran rhinoceros (Dicerorhinus sumatrensis)” is published by the Journal of Heredity(doi.org/10.1093/jhered/esy019).
Co-authors also include Peter J. Van Coeverden de Groot (Queen’s University in Canada), Kelsey E. Witt (University of Illinois), Paige K. Engelbrektsson (National Museum of Natural History), Kristofer M. Helgen (University of Adelaide), Ripan S. Malhi (University of Illinois), and Oliver A. Ryder (Institute of Conservation Research, San Diego Zoo).
The Carl R. Woese Institute for Genomic Biology research facility at the University of Illinois is dedicated to transformative research and technology in life sciences using team-based strategies to tackle grand societal challenges.
This Op-Ed by Jeremy Hance appeared in the Sydney Morning Herald on 17 March 2018.
There could be as few as 30 Sumatran rhinos left in the wild.
Photo: Jeremy Hance
In Rudyard Kipling’s classic story of how the rhino got his skin, the titular character is an unmannered lout. This is how the public imagines rhinos: aggressive, dumb and grumpy – charge first, ask questions never. But in 2010 when I met my first Sumatran rhino, a fellow named Tam, he whistled at me like a curious dolphin and rubbed his horn against my shirt like a cat. I’ve been in love ever since.
The Sumatran rhino is arguably the most imperiled large terrestrial mammal on the planet. Indonesia – where the last of the species survive – says there are 100 left in the wild. But the real number may be closer to 50 – and it could be as bad as 30. I’ve been told by some conservationists it’s too late for this species, but as someone who’s had the pleasure of spending a few precious hours with Sumatran rhinos I’m not ready to throw in the towel.
Sumatran rhinos are lovably weird. It’s as if Mother Nature combined a big pig, a yak, and an oversized dog. Then, as a joke, she stuck a couple horns on her creation. Unlike other rhinos, Sumatran rhinos sport a coat of hair, sometimes resplendently red. They are small – compared with other rhinos – but large compared with most everything else. And they are the most vocal of all the rhinos – they sing like whales and snort and puff in a manner that says “hello, I’m hungry”. They are nearly constantly chattering. Dumb? Hardly.
Evolutionarily, Sumatran rhino are unlike any other rhino on earth. They belong to an ancient genus – Dicerorhinus – that split off from other rhinos around 25 million years ago – long before we ever walked the earth. Researchers also believe they may be the last living relative of the famous woolly rhino.
But why should we spend effort and money on trying to save a species when we may fail in the end? There are number of practical reasons.
The multitude of species – called biodiversity – underpins every ecosystem on earth and humans won’t survive without functioning ecosystems. Every species play a role. Little ecological research has been done on the Sumatrans rhino, but we can make some guesses. When Sumatran rhinos make wallows, they likely create habitat for smaller species. When they poop, they deliver important food sources for nature’s cleaners like beetles and fungi. And when Sumatran rhinos eat – and they eat a lot – they can change the understory of the forest.
When we lose a species – any species – we are essentially taking a brick out of the foundation of life on Earth. How many bricks can we lose before the walls start coming down?
But I don’t really care about all these arguments, no matter how convincing. We should save the Sumatran rhino because we can. Humans have become the dominant species planet-wide: we are altering the climate, razing forests and acidifying the oceans. We are bending the ecology of the Earth in ways that would have been unimaginable just 50 years ago. So, we have a moral obligation to do whatever is possible to mitigate any damage and save as much life on our little planet as possible, small or large, grumpy or chill.
Despite how close Sumatran rhinos are to extinction, there is one bright spot. The Sumatran Rhino Sanctuary, located in the island’s Way Kambas National Park, has produced two hairy, big-eyed babies in the last six years – Andatu, a boy, and Delilah, a girl. Sumatran rhinos are notoriously difficult to breed – but we’ve cracked that nut.
The solution then according to numerous scientists I’ve talked to over the last year is to bring more Sumatran rhinos into sanctuaries and breed the hell out of them. Make more babies like Andatu and Delilah. There is precedent for this: aggressive captive breeding programs saved both the European bison and the Arabian oryx from oblivion during the 20th century.
The biggest obstacle to doing just this for the Sumatran rhino is the government of Indonesia. Nothing concrete can happen for the species without the government’s approval, but it has dragged its feet for years – wasting critical time. So, I am calling on President Joko Widodo, who is now visiting Australia, to take the initiative and call for a bold, new action plan for the species that goes into effect immediately. Not for ourselves, but for our children and the countless generations to come. Not even for humanity, but because there’s nothing in all the universe quite like the littlest rhino.
Jeremy Hance is a freelance journalist. He recently wrote a four part series on the species for Mongabay.
You can read the original SMH article here