Mini-brain of Sumatrans

The researchers obtained induced pluripotent stem cells (iPSCs) from the last male Sumatran rhinoceros and grew brain organoids from them. As the authors note, organoids will help to replenish knowledge about the evolutionary development of mammals.

The sixth mass extinction is progressing at an unprecedented rate. The five extant rhino species are particularly affected by poaching, as well as habitat destruction and fragmentation.

The Sumatran rhinoceros, also known as the Asian two-horned rhinoceros, is the smallest and oldest extant species of rhinoceros. There are less than 80 individuals of this species left. They once inhabited a vast territory in East and Southeast Asia, but now only small scattered populations are scattered across Sumatra and Indonesian Borneo. Habitat loss and limited breeding in captivity are the biggest threats to the species and lead to a reduction in numbers.

Since the rate of reproduction of rhinos during captive breeding is too low, an innovative tool is needed to combat extinction. In a new study, Sebastian Dicke and his colleagues from the Max Delbruck Center for Molecular Medicine at the Helmholtz Association obtained iPSCs from fibroblasts of the last male Sumatran rhinoceros, who died in 2019, and comprehensively studied them.

The ultimate goal of the researchers is to grow viable sperm cells to preserve the species in the future. Obtaining fertile and viable offspring from iPSCs has been successfully demonstrated in mice, and this process is increasingly being applied to many other mammalian species.

iPSCs from endangered species allow us to study species-specific development processes. Since the embryonic material of exotic large mammals is very limited or practically inaccessible, iPSCs are an unprecedented tool for obtaining information about embryogenesis and organogenesis.

The researchers carefully characterized both the initial fibroblasts and iPSCs from the Sumatran rhinoceros and demonstrated the potential of differentiation of the latter into three germ layers. Growing brain organoids from iPSCs proves their ability to generate complex three-dimensional structures. Organoids developed in a self-organizing manner and expressed all the tested neural markers. 

Thus, this work represents the first step in the fight against the extinction of Sumatran rhinos using bioengineering technologies.

Article V.Zywitza et al. Induced pluripotent stem cells and cerebral organoids from the critically endangered Sumatran rhinoceros is published in the journal iScience.

Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru .