Genome-engineered C. elegans strains with sex-transformed neurons and gut

Abstract

The sexual identity of specific tissues can be altered through cell-autonomous manipulation of the sex determination pathway in the nematode Caenorhabditis elegans. Previously described sexually mosaic strains carried multicopy transgenic arrays that are potentially subject to transgene silencing or misexpression artefacts. We used here the CRISPR/Cas9 system to engineer strains in which coding sequences for either a masculinizing agent (FEM-3) or a feminizing agent (intracellular domain of TRA-2) are inserted with a trans-splicing system at the 3 end of endogenous genetic loci that are known to be expressed in either a neuron-specific (rab-3) or gut-specific (elt-2) manner. We validate the tissue-specific sex-transformations induced by these genomic manipulations through expression analysis of known sex-specific genes and through assaying behavioral readouts. These strains may serve the worm community as standard reference tools to study the consequences of tissue-specific sex transformations.