Project description:Bornean orangutans (Pongo pygmaeus) are an endangered non-human primate species. Induced pluripotent stem cells (iPSCs) offer a promising avenue for preserving genetic resources and studying evolutionary processes. In this study, we successfully generate Bornean orangutan iPSCs (o-iPSCs) from peripheral blood mononuclear cells using Sendai virus-mediated reprogramming. Furthermore, we transform primed o-iPSCs into a naïve pluripotent state using a novel 4i/L/A culture system. The resulting naïve o-iPSCs exhibit key features similar to human naïve stem cells, including upregulation of KLF17, DNMT3L, and DPPA3/5. We also observe significant activation of the WNT signaling pathway and X chromosome reactivation in the 4i/L/A o-iPSCs. Transcriptome analysis confirmed their resemblance to human naïve embryonic stem cells. Our findings contribute to the molecular understanding of naïve o-iPSCs and provide a foundation for orangutan conservation using advanced technologies.
Project description:Yawning is highly contagious, yet both its proximate mechanism(s) and its ultimate causation remain poorly understood. Scholars have suggested a link between contagious yawning (CY) and sociality due to its appearance in mostly social species. Nevertheless, as findings are inconsistent, CY's function and evolution remains heavily debated. One way to understand the evolution of CY is by studying it in hominids. Although CY has been found in chimpanzees and bonobos, but is absent in gorillas, data on orangutans are missing despite them being the least social hominid. Orangutans are thus interesting for understanding CY's phylogeny. Here, we experimentally tested whether orangutans yawn contagiously in response to videos of conspecifics yawning. Furthermore, we investigated whether CY was affected by familiarity with the yawning individual (i.e. a familiar or unfamiliar conspecific and a 3D orangutan avatar). In 700 trials across 8 individuals, we found that orangutans are more likely to yawn in response to yawn videos compared to control videos of conspecifics, but not to yawn videos of the avatar. Interestingly, CY occurred regardless of whether a conspecific was familiar or unfamiliar. We conclude that CY was likely already present in the last common ancestor of humans and great apes, though more converging evidence is needed.