The evolution of morphology at a single-cell resolution
Authors: Ella Preger-Ben Noon; Yifat Yanku; Anna Urum; Stav Naky
Affiliation: Technion - Israel Institute of Technology, Haifa, Israel
Keywords: d. evolution of gene expression; f. pattern formation
The evolution of animal body form results from genome divergence. How genome divergence is translated into the morphogenetic events that generate new phenotypes is one of the most challenging questions in modern evolutionary biology. We address this question by studying the evolution of male genitalia in Drosophilids. Many anatomical features of the genitalia of D. melanogaster and its close relatives exhibit striking differences in shape and size, providing an excellent system to study the genetic, molecular and developmental basis of phenotypic evolution. Genetic mapping studies revealed that these differences are affected by multiple loci, but the evolved genes and how they coordinately function to generate diverse structures remains unknown.
The emergence of single-cell genomics provides an unprecedented opportunity to resolve these problems. Here, we use single-cell RNA-seq to generate gene expression atlases of genital discs of D. melanogaster and its sibling species D. simulans. This approach allows us to unbiasedly identify genes that are differentially expressed in evolved genital substructures between the two species. By combining unsupervised cell-clustering with published gene expression pattern data we obtained transcriptomes for each of the anatomical substructures of the genital disc and identified all the evolved genes within these substructures. Functional analyses using the powerful genetic toolkit of Drosophila will determine the relevance of these genes to male genitalia development and evolution.