Reconstruction of the Prox gene family evolution in vertebrates reveals multiple lineage-specific gene losses

Abstract

Prospero-related homeobox (Prox) genes encode a family of transcription factors that play essential roles in the development of several organs and systems, including the central nervous system, lymphatic endothelium, musculature, and liver. Despite their developmental importance, the evolutionary history of the vertebrate Prox gene family remains poorly understood. In this study we combined phylogenetic and synteny analysis to characterise the evolution of the Prox family in vertebrates. Our results reveal that two to three Prox subfamilies were already present in the last common ancestor of jawed vertebrates. We clarify the identity and evolutionary relationships of well-studied members of this family and identify multiple independent losses of Prox2 and Prox3 genes in specific vertebrate lineages. Furthermore, we uncover evidence for the existence of a fourth Prox gene in the ancestral vertebrate genome, which was subsequently lost. Overall, this study provides the first comprehensive analysis of the evolutionary history of the vertebrate Prox gene family and establishes a foundations for future studies on the functional roles of these genes.