Structural organization of the mating-type locus in Clade 3 of Fusarium solani species complex and development of PCR protocol for identification of MAT idiomorphs

Mating compatibility in ascomycetes is regulated by the mating-type locus. In this study, whole-genome sequence data were used to characterize the structural organization of the MAT loci in two heterothallic and one homothallic species of Clade 3 from Fusarium solani species complex FSSC. Based on sequence analysis, we identified MAT1-1 idiomorph in Fusarium paranaense with three genes, MAT1-2 idiomorph in F. solani f. sp. piperis with two genes, and both MAT idiomorphs in F. striatum, homothallic species. The structural organization of the MAT1-1 locus in F. paranaense, like the MAT1-2 locus in F. striatum and F. solani f. sp. piperis was different to those of other FSSC-Clade 2 and Fusarium species. Moreover, the mating-type genes sequences in FSSC-Clade 3 were dissimilar resulting in a distinct amino acid profile. Despite these differences in the studied species, the process of sexual reproduction is not affected. Besides, we developed primers and applied in a reliable PCR protocol to MAT idiomorph identification. This paper presents the first investigation of the structural organization of the MAT locus from FSSC-Clade 3. The availability of MAT genes sequences can give support to downstream functional studies of individual mating-type transcripts. The MAT primers will be useful to assess the reproductive mode in other strains of FSSC-Clade 3, and to facilitate the application of the biological concept through sexual crosses.