Year: 2026
Type: preprint
Abstract: Single-cell RNA sequencing (scRNA-seq) can provide new insights into the regulation of developmental processes by revealing unknown or overlooked genes. We identified a novel gene called beer belly ( bebe ) as a marker of a segment addition zone (SAZ) associated cell cluster in a single-cell atlas of the spider Parasteatoda tepidariorum . Here we show that bebe is an ancient toolkit gene encoding a previously uncharacterised protein predicted to be secreted, which likely plays an important role in the development of most animal phyla. However, we could not identify a bebe ortholog in any mammal or holometabolous insect, suggesting it has been lost in these lineages and explaining why it has been overlooked to date. Knock-down of bebe expression in P. tepidariorum demonstrates that it regulates SAZ size and consequently segment size by interacting with Wnt8 . Our findings also suggest that bebe may regulate segmentation in other invertebrates and play additional developmental roles in bilaterian and non-bilaterian animals, and likely ancestrally, through modulation of Wnt signalling. This study emphasises the promise of applying single-cell sequencing across a diverse range of species to better understand the regulation of development beyond candidate genes from traditional models, allowing us to better characterise the animal developmental toolkit and its evolution.
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Awards: G1279712735, SPP 2349: Die Genomischen Grundlagen Evolutionärer Innovationen (GEvol), Investigating the genomic and phenotypic consequences of recurrent whole genome duplication in spiders, Boundary formation in sea anemone oral-aboral patterning, G3463347175, Gen und Genomduplikation und phänotypische Neuerungen – Erkenntnisse aus Spinnen und Insekten, G8526945721
OpenAlex ID: W7223801839