Adaptive cellular evolution in the intestinal tracts of hyperdiverse African cichlid fishes [scRNA-Seq]

While the evolution of feeding structures has been studied extensively in this context, the nature of dietary adaptations in the digestive tract remains largely unexplored. Here, we investigate the cellular and molecular basis of dietary adaptations in the massive radiation of cichlid fishes in Lake Tanganyika using comprehensive single-cell transcriptomic data derived from the intestines of 25 African cichlid species with distinct habitats and diets.

We show that, at the cellular level, dietary adaptations are primarily driven by anterior enterocytes, and that both the abundance and gene expression profiles of these cells have evolved in response to dietary specializations. These dietary adaptations in enterocytes are driven by rapidly evolving cell population-specific genes, suggesting that alterations in gene regulatory programmes and cell-state specification promote ecological diversification.