Monday, 10 December, 2018

Scientists create embryos to save near-extinct rhino

A northern white female rhinoceros named Najin at Ol Pejeta Conservancy in Kenya in 2015 A northern white female rhinoceros named Najin at Ol Pejeta Conservancy in Kenya in 2015
Sandy Nunez | 06 July, 2018, 21:16

But now they have used frozen northern white rhino sperm to create embryos to implant into a female rhinoceros.

Keeper Zachariah Mutai attends to Fatu in the pen where she is kept for observation, at the Ol Pejeta Conservancy in Laikipia county in Kenya.

The worldwide team of researchers successfully managed to adapt reproduction techniques used in horses to the special circumstances of rhino species, opening up the potential to bring back the northern white from the brink of extinction.

They plan to harvest the females' egg cells soon and produce "pure" northern white rhinos to be borne by a southern white surrogate in three years.

The European team of researchers created a few early-stage rhino embryos using a technique called intracytoplasmic sperm injection or ICSI. First, that rhino eggs can be captured from live females.

The team was able to extract 13 eggs from 12 female southern white rhinos.

Step three is the in vitro fertilisation of the egg with the sperm.

However, even if the implantation of clean embryos in future will result in the appearance of healthy offspring, the Northern white Rhino is facing another big problem: lack of genetic diversity required for healthy populations.

Efforts have been made in the past to create a sustainable northern white rhino population, through both natural breeding programmes and artificial insemination, but were unsuccessful.

It will then be planted into surrogate mothers (Southern White rhino), who are under heavy guard at the conservancy, the researchers said.

Using in vitro fertilization (IVF), the researchers extracted sperm that had previously been frozen from NWR males and implanted it into eggs from the SWR to create the hybrid embryos.

Anthony Bourdain's Will Reveals Fortune Goes Mostly to Daughter
He began dating actress Asia Argento in early 2017 and publicly supported Argento after she accused Harvey Weinstein of rape . The pair married in 2007 and separated in 2016, but their divorce was never finalized - legally, she's still his next of kin.

The short timeline is necessary, he said, so that a baby northern white rhino could be socialized by members of its own subspecies.

An global team of zoologists, veterinarians and other researchers plucked unfertilized eggs from southern white rhinoceroses, a closely related subspecies with a population of about 20,000. And if the method works for the rhino, it should be possible to extend it to other endangered large mammals.

In 1960, roughly 2,000 northern white rhinos roamed central Africa.

To my mind, the time to save the northern white rhino has passed.

This was done while the female southern white rhino was under general anaesthetic, but the process is still very risky. The objective of simply preserving the subspecies' genes in a new hybrid rhino (in captivity), and whether it would be worth all the effort, is unclear.

There's a second way to make them, also.

Supporters believe the work could be used to help other endangered species, while some conservationists believe the focus should be on other critically endangered species, including the Javan and Sumatran rhinos, that have suffered because of poaching and human encroachment on habitats.

The rhino's disappearance has left a void in the region's ecosystem that could have significant impacts in the future, Hildebrandt said.

There are already southern white rhino now living and breeding in Uganda at the Ziwa Sanctuary.

The result - viable embryos containing genetic material from a sub-species that is already functionally extinct. Taxon substitution using the southern white rhino would be simpler and more cost-effective than manipulating genes and introducing manufactured hybrids, and would likely have a higher probability of success. "We ... were highly afraid that something unexpected would happen during this procedure", Hildebrandt told a telephone briefing. They also envisioned to bringing already extinct species back from the dead. We need action now. Otherwise, I fear that we will still be loading samples onto the frozen ark as the lights go off on an otherwise empty Planet Earth.