stem cells

Saving The Sumatran Rhino | Earth Wise

January 2, 2023 By EarthWise Leave a Comment

The Sumatran rhinoceros is the smallest and most ancient rhino species and is the only surviving species with hair. It is critically endangered. Because of poaching and habitat destruction, there are fewer than 50 of them left in the wild and those are scattered in the rainforests of Sumatra and the Indonesian part of Borneo. Mating encounters between surviving males and females are increasingly rare.

The last male Sumatran rhino in Malaysia died in 2019 but cell samples from that individual are the basis of an ambitious effort in bioengineering.

Researchers from the Max Delbruck Center in Germany are taking skin cells from the deceased rhino and turning them into stem cells. The hope is to use these stem cells to derive egg and sperm cells to be the basis of assisted reproduction. Fertilization would take place in a petri dish. The resultant embryos would then be carried to term by surrogate rhino mothers.

The researchers have reported success generating induced pluripotent stem cells or IPS cells from the rhino skin samples. IPS cells are able to divide indefinitely and can transform into any cell type in the body.

The next step is to try to cultivate primordial germ cells – the precursors of eggs and sperm.

This work is going on because it is increasingly difficult to preserve the Sumatran rhino population by gathering together remaining individuals in wildlife Reserves. Females that have not been pregnant for a long time often become infertile because of cyst growth on their reproductive organs, and some are just too old to bear young.

It may take extraordinary efforts like these to save these animals from extinction.

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A second chance for the Sumatran rhino

Photo, posted April 30, 2008, courtesy of Willem V. Strien via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Resurrecting The Tasmanian Tiger | Earth Wise

September 16, 2022 By EarthWise Leave a Comment

Tasmanian tigers earned their nickname because of the stripes along their back, but they were not felines. In fact, they were carnivorous marsupials, the type of Australian mammal that raises its young in a pouch.

Tasmanian tigers, also known as thylacines, were once native to the Australian mainland, as well as the islands of Tasmania and New Guinea. Dog-like in appearance, Tasmanian tigers were extensively hunted after European colonization. The last known Tasmanian tiger died in captivity in 1936.

Nearly 100 years after its extinction, the Tasmanian tiger may live once again. Scientists in Australia and the United States have launched an ambitious multimillion dollar de-extinction project to genetically resurrect the Tasmanian tiger.

In order to bring back the animal, researchers will have to take stem cells from a living species with similar DNA – like the fat-tailed dunnart – and use gene editing techniques to turn them into “Tasmanian tiger” cells – or the closest approximation possible. The team will need new assisted reproductive technologies to use the stem cells to make an embryo, which will then have to be transferred into an artificial womb or a dunnart surrogate to gestate. The research team is optimistic that there could be a hybrid baby Tasmanian tiger in 10 years.

The ambitious project is a partnership between scientists at the University of Melbourne and the Texas-based company Colossal Biosciences. This is the second de-extinction undertaking by Colossal Biosciences, which announced last year it planned to use its technology to recreate the woolly mammoth, and return it to the Arctic tundra.

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Scientists want to resurrect the extinct Tasmanian tiger

Tasmanian tiger: Scientists hope to revive marsupial from extinction

Photo credit: E.J. Keller, from the Smithsonian Institution archives, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cell-Based Meat And Seafood | Earth Wise

February 8, 2021 By EarthWise Leave a Comment

We have heard about laboratory meat for a number of years, generally in terms of something that may happen at some point in the indeterminate future. But at least for a couple of California companies, that future is now.

These high-tech companies are producing products – real meat and seafood – that are originally cultured from animal cells but are made without the actual animal.

San Francisco-based Eat Just makes chicken nuggets that have recently gained regulatory approval in Singapore and are now available to order at a downtown restaurant. San Diego’s BlueNalu creates cell-based seafood fillets including yellowtail, mahi-mahi, red snapper, and tuna.

The companies use stem cells obtained from actual animals and cultivate them in steel tanks with the same nutrients that living animals consume. The original cell donor is not sacrificed. The harvested cells multiply and are eventually shaped to form meat or fish that cooks, looks, and tastes just like its natural counterpart.

The “mouth feel” of conventional meat or fish can be mimicked by recreating the same proportions of muscle, fat, and connective tissue in the cell-based product. Eat Just says their product cooks, looks, and tastes like chicken because it is chicken. BlueNalu says their product has all the same characteristics as fish because it is fish.

These products have major environmental, safety, and ethical advantages. The big question is whether people will eat them. Is there an “ick factor” to overcome? Ultimately, the key thing is how they taste. If they pass muster on that score and cell-based meats and seafood are scaled up and accepted, we can have the nutritional and sensory advantages of meat proteins without the environmental, ethical and safety disadvantages.

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Can We Enjoy Meat and Seafood and Save the Planet?

Photo, posted February 1, 2012, courtesy of Andrea Parrish-Geyer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.