Stem cells (and mini brains) grown from critically endangered rhinos


The Sumatran rhino is critically endangered and difficult to breed. But now, researchers have created induced pluripotent stem cells (iPSCs) from the genetic material of a male, potentially providing new ways to help conservation efforts. They even used them to grow mini rhino brains in the lab.

Once widespread across southeast Asia, there are now fewer than 80 individual Sumatran rhinos left on Earth. Habitat loss and poaching for its horn are the main threats to its existence, and conservation efforts haven’t been as successful as hoped because the animals don’t thrive in captivity, and struggle to breed.

To give them a much needed leg up, scientists at the Max‐Delbrück‐Center for Molecular Medicine (MDC) have turned to lab-based tools. Mature cells can be reprogrammed to become iPSCs, which can in turn become almost any other cell in the body – and in this study, the team generated iPSCs out of skin cells taken from Kertam, the last male Sumatran rhino in Malaysia, who died in 2019.

These iPSCs were found to successfully produce cells from the three germ layers – the endoderm, mesoderm and ectoderm – which in turn can give rise to all of an animal’s tissues and organs. Next, the researchers used the stem cells to grow cerebral organoids – essentially, miniature rhino brains – in lab dishes. All neural markers tested for were detected, indicating the potential of these cells to produce complex organs.

But of course, the most important implication from this work is that iPSCs could be used to help improve the success of breeding Sumatran rhinos and increase their genetic diversity. Kertam’s legacy could live on long past his death.

“We conserved his genetic information and created an opportunity to produce viable spermatozoa for breeding purposes in the future,” said Vera Zywitza, first author of the study. “As the quality of semen collected from Sumatran rhinos is poor directly after retrieval and even worse after cryopreservation and thawing, in vitro-generated spermatozoa offer a great alternative for assisted breeding of Sumatran rhinos in general.”

The research was published in the journal iScience.

New Atlas, 14 November 2022