Development of a Molecular Marker Linked to the A4 Locus and the Structure of HD Genes in Pleurotus eryngii

Allelic differences in A and B mating-type loci are a prerequisite for the progression of mating in the genus Pleurotus eryngii; thus, the crossing is hampered by this biological barrier in inbreeding. Molecular markers linked to mating types of P. eryngii KNR2312 were investigated with randomly amplified polymorphic DNA to enhance crossing efficiency. An A4-linked sequence was identified and used to find the adjacent genomic region with the entire motif of the A locus from a contig sequenced by PacBio. The sequence-characterized amplified region marker 7-2299 distinguished A4 mating-type monokaryons from KNR2312 and other strains. A BLAST search of flanked sequences revealed that the A4 locus had a general feature consisting of the putative HD1 and HD2 genes. Both putative HD transcription factors contain a homeodomain sequence and a nuclear localization sequence; however, valid dimerization motifs were found only in the HD1 protein. The ACAAT motif, which was reported to have relevance to sex determination, was found in the intergenic region. The SCAR marker could be applicable in the classification of mating types in the P. eryngii breeding program, and the A4 locus could be the basis for a multi-allele detection marker.

Mating Type Analysis of Dermatophytes using Mating Type Gene / 대한의진균학회지

BACKGROUND: Traditionally, mating types of dermatophytes had been identified by mating experiments. It took a long time and there were many limitations. Recently, we can figure out the fungal mating types using molecular mating type analysis by detecting mating type (MAT) genes. The mating type (+) specific gene of the high-mobility-group (HMG) DNA binding domain and the mating type (-) specific gene of alpha-box were found in Arthroderma simii and A. vanbreuseghemii. OBJECTIVE: We applied this molecular mating type analysis to strains of Trichophyton interdigitale, T. rubrum, Microsporum canis in Korea and compared these results with previous reports. METHODS: Thirty-four strains of T. interdigitale (12 granular types, 9 powdery types, 8 purple-red types, 5 cottony types), 5 strains of T. rubrum, and 5 strains of M. canis were examined. We analyzed ribosomal RNA internal transcribed space 1, 4 sequencing of T. interdigitale subtypes and investigated the mating type of dermatophytes using alpha-box gene and HMG gene primers. RESULTS: Among 12 strains of granular type of T. interdigitale, 9 strains were type (-) and other 3 strains were type (+). All of them were zoophilic. All strains of powdery, purple-red and cottony types of T. interdigitale were type (+) and anthropophilic. In T. rubrum and M. canis, all strains were type (-). These results were matched with previously reported studies. CONCLUSION: The molecular mating type analysis of dermatophytes was quicker method than conventional mating experiments. Moreover, MAT genes are highly conserved even in apparently asexual fungi. The results were well matched with previous reports with traditional mating tests.