Engineering the Caenorhabditis elegans Genome by Mos1-Induced Transgene-Instructed Gene Conversion

Mos1 -induced t ransgene-i nstructed gene c onversion (Mos TIC) is a technique of choice to engineer the genome of the nematode Caenorhabditis elegans . Mos TIC is initiated by the excision of Mos1 , a DNA transposon of the Tc1/Mariner super family that can be mobilized in the germ line of C. elegans . Mos1 excision creates a DNA double-strand break that is repaired by several cellular mechanisms, including transgene-instructed gene conversion. For Mos TIC, the transgenic repair template used by the gene conversion machinery is made of sequences that share DNA homologies with the genomic region to engineer and carries the modifications to be introduced in the genome. In this chapter, we present two Mos TIC protocols routinely used.