Table 2.

Transposon strategies in fungi.

Transposase (TPase)	Pro	Con	References
TPase driven by an inducible promoter, integrated into the genome	•Usable in most fungi	•Inducible promoters are often leaky and transposon mutants are unstable (the transposase can work on inserted transposons and excise them again)	Li et al., 2011; Gao et al., 2018; Mielich et al., 2018; Segal et al., 2018; Zhu et al., 2018a
TPase driven by an inducible promoter, on a plasmid	•Stable transposition upon removal of the plasmid	•Some fungi do not support plasmids	Gangadharan et al., 2010; Guo et al., 2013; Michel et al., 2017; Edskes et al., 2018; Mutumwinka et al., 2018; Zhu et al., 2018b; Gale et al., 2020
TPase driven by an overexpression promoter, on a plasmid	•Stable transposition upon removal of the plasmid	•Some fungi do not support plasmids •Transposition can only be controlled by removal of the plasmid	Patterson et al., 2018
Transposon (TP)	Pro	Con
Inside a selectable feature (on a plasmid or in the genome)	•Transposition from the genome is possible in most fungi	•Some transposons leave excision scars, making selection less efficient	Michel et al., 2017
With a selection marker as cargo, on a plasmid	•Clear insertion selection upon removal of the plasmid	•Some fungi do not support plasmids	Gangadharan et al., 2010; Guo et al., 2013; Edskes et al., 2018; Gao et al., 2018; Mutumwinka et al., 2018; Patterson et al., 2018; Zhu et al., 2018a; Gale et al., 2020
Inside a gene or promoter of a selection marker with another selection marker as cargo, integrated in the genome or on a plasmid	•Transposition from the genome is possible in most fungi •Clear insertion selection	•Some transposons leave excision scars, making excision selection less efficient	Li et al., 2011; Mielich et al., 2018; Segal et al., 2018; Zhu et al., 2018b