Xian Hui Chang (INRAE, Toulouse)
02/04/2026 10:30 - 12:00
Emplacement: Aurigny Room
Pangenomes are an emerging alternative to standard linear reference genomes that are capable of representing the genetic diversity present in a population. Pangenomes are often represented using variation graphs where common sequences are collapsed into single nodes. Although variation graphs are a relatively efficient method of representing pangenomes, they become increasingly large and complex as more diverse samples are added. One method to find structure in the graph is to decompose it into common topological motifs called snarls. In this talk I will present two projects that use the snarl decomposition to simplify the graph and identify sites of genetic variation. The first uses the topological definition of snarls to calculate distances for the chaining step of long read mapping. The second uses snarls as the definition of genetic variants for performing genome-wide association studies (GWAS).