Heterothallism and potential hybridization events inferred for twenty-two yellow morel species

Abstract

Mating-type genes are central to sexual reproduction in ascomycete fungi and result in the establishment of reproductive barriers. Together with hybridization, they both play important roles in the evolution of fungi. Recently, potential hybridization events and MAT genes were separately found in the Elata Clade of Morchella. Herein, we characterized the MAT1-1-1 and MAT1-2-1 genes of twenty-two species in the Esculenta Clade, another main group in the genus Morchella, and proved heterothallism to be the predominant mating strategy among the twenty-two species tested. Ascospores of these species were multi-nuclear and had many mitochondrial nucleoids. The number of ascospore nuclei might be positively related with the species distribution range. Phylogenetic analyses of MAT1-1-1, MAT1-2-1, intergenic spacer (IGS), and partial histone acetyltransferase ELP3 (F1) were performed and compared with the species phylogeny framework derived from the ribosomal internal transcribed spacer region (ITS) and translation elongation factor 1-alpha (EF1-a) to evaluate their species delimitation ability and investigate potential hybridization events. Conflicting topologies among these genes genealogies and the species phylogeny were revealed and hybridization events were detected between several species. Different evolutionary patterns were suggested for MAT genes between the Esculenta and the Elata Clades. Complex evolutionary trajectories of MAT1-1-1, MAT1-2-1, F1 and IGS in the Esculenta Clade were highlighted. These findings contribute to a better understanding of the importance of hybridization and gene transfer in Morchella and especially for the appearance of reproductive modes during its evolutionary process.

Mating-Type Genes Play an Important Role in Fruiting Body Development in Morchella sextelata

“…The measurement of the length and width of the ascospores indicated that the size of the M1 type (n = 70) was significantly smaller than that of the M2 type (n = 70), and the size of the Mix type (n = 70) was the largest ( Figure 5 b). Nuclear staining by DAPI showed that there were multiple nuclei, consistent with the results of Du et al [ 20 ], and there was no difference in the number of nuclei between the three types of ascospores ( Figure 5 c).…”

“…To visualize the nuclei, ascospores were stained with 4′-6-diamidino-2-phenilindole (DAPI). The ascospores were incubated directly in the staining reagent on the microscope slide for 15 min [ 20 ]. The thickness of each layer of pileus in the fruiting bodies and the size of ascus and ascospore were measured using ImageJ software ( , accessed on 10 May 2020).…”

Multilocus phylogenies reveal three new truffle-like taxa and the traces of interspecific hybridization in Octaviania (Boletaceae, Boletales)

“…Brasier et al 1999 ; Depotter et al 2016 ; Feurtey et al 2019 ; Newcombe et al 2000 ; Schardl and Craven 2003 ; Stukenbrock 2016 ), yeasts (e.g., Gostinčar et al 2018 ; Kuehne et al 2007 ; Leducq et al 2016 ; Marcet-Houben and Gabaldón 2015 ) and morels ( Morchella spp.) (Du et al 2016 , 2019 , 2020 ) but has been rarely reported in mushroom-forming basidiomycetes (Anderson et al 1980 ; Stenlid and Karlsson 1991 ). Orihara et al ( 2016a ) illustrated that the frequent topological incongruences among gene trees of the sequestrate bolete genus, Rossbeevera , which is closely related to Octaviania , were likely to be derived from intraspecific gene introgression as well as incomplete lineage sorting (ILS).…”

Correction to: Heterothallism and potential hybridization events inferred for twenty-two yellow morel species

“…Following the publication of the original article (Du et al 2020 ), we were notified of two mistaken pairs of primer sequences in Table 2, as shown below.…”