Heritable genetic transformation of Strongyloides stercoralis by microinjection of plasmid DNA constructs into the male germline.

Heretofore, transgenesis in the parasitic nematode genus Strongyloides has relied on microinjecting transgene constructs into gonadal syncytia of free-living females. We now report transgenesis in Strongyloides stercoralis by microinjecting constructs into the syncytial testes of free-living males. Crosses of individual males microinjected with a construct encoding GFP with cohorts of 12 non-injected females produced a mean of 7.28±2.09 transgenic progeny. Progeny of males and females microinjected with distinct reporter constructs comprised 2.6%±0.7% of individuals expressing both paternal and maternal transgenes. Implications of this finding for deployment of CRISPR/Cas9 mutagenesis in Strongyloides spp. are discussed.