A Human-Evolved Gli2 Enhancer is Required for Normal Male Aggression
Human accelerated regions (HARS), which are genome sequences that have evolved at an accelerated rate in the human lineage, have previously been shown to include developmental enhancers. I have used a massively parallel enhancer reporter assay (MPRA) to test a library of human and chimp HAR orthologs in a cell model of mammalian testes, in order to find HARS which have evolved in human and may underly unique human reproductive traits. Through luciferase assay, 4C-seq, transcriptional analysis and Crispr/Cas9 deletion I have validated a candidate and shown that it is an enhancer of the hedgehog signaling pathway effector Gli2 in the testis cell model. Furthermore, I have shown that the enhancer is required for normal Gli2 expression in Leydig cells, as well as normal testis vascular development and normal inter-male social behavior.