The first nonclassical Tc1 transposon discovered in yeast

Abstract Background Identification of transposons or retrotransposons is still a difficult task and can not be accomplished without specialist knowledge. Tc1/mariner is a superfamily of DNA transposons that have been discovered in animals, plants, and fungi. Tc1/mariner transposons are probably the most widespread DNA transposons in nature. However, Tc1 transposons have not been identified and characterized in yeast and their nucleotide sequences are not available in public databases. Results In the present study, we reported the discovery of two intact Tc1 transposons in yeast and. filamentous fungi, respectively. The first one, named Tc1-OP1, can be used as a signature of Ogataea parapolymorpha. The second one, named Tc1-MP1, represents a subfamlily of Tc1 transposons in Rhizopus, Mucor, Circinella, etc. Notablely, Tc1-OP1 may encode a protease and a transposase, challenging the classical model of DNA transposons. Conclusions Tc1-OP1 is the first reported Tc1 transposon in yeast. Tc1-OP1 and Tc1-MP1 can be used for the identification and characterization of Tc1 transposons in future studies. The discovery of Tc1-OP1 revealed a nonclassical model of DNA transposons, which could challenge and enrich fundamental concepts of DNA transposons.