Single-nucleus transcriptomic atlas of postnatal camel liver development identifies candidate adaptive features

Camels possess distinctive physiological traits related to metabolism and environmental resilience, highlighting the need to characterize liver cellular composition in this species. We used single-nucleus RNA sequencing to generate a developmental atlas of the Bactrian camel ( Camelus bactrianus ) liver using one individual from each of the newborn, weaning, and adult stages, analyzing 57,036 cells and identifying 19 cell types, including hepatocytes, liver sinusoidal endothelial cells (LSECs), and immune cells. We identified a unique subtype of HGFAC+ LSECs that was not observed in the available cattle or human datasets, characterized by high expression of hepatocyte growth factor activator ( HGFAC ), which is known to activate hepatocyte growth factor ( HGF ). Hepatocyte pseudotime ordering was consistent with a putative transition from proliferation-associated states toward metabolically annotated states. In the samples collected in this study, Kupffer cells were more represented in the newborn sample, whereas T-cell subsets were more represented in the adult sample. Exploratory cross-species mapping indicated shared transcriptional features between several adult camel and cattle immune cells. These results suggest liver biochemical features that may contribute to camel resilience to arid conditions, providing a resource for further studies of camel liver biology and livestock adaptation to harsh environments.