The Genetic Linkage Map of the Medicinal Mushroom Agaricus subrufescens Reveals Highly Conserved Macrosynteny with the Congeneric Species Agaricus bisporus

Abstract

Comparative linkage mapping can rapidly facilitate the transfer of genetic information from model species to orphan species. This macrosynteny analysis approach has been extensively used in plant species, but few example are available in fungi, and even fewer in mushroom crop species. Among the latter, the Agaricus genus comprises the most cultivable or potentially cultivable species. Agaricus bisporus, the button mushroom, is the model for edible and cultivable mushrooms. We have developed the first genetic linkage map for the basidiomycete A. subrufescens, an emerging mushroom crop known for its therapeutic properties and potential medicinal applications. The map includes 202 markers distributed over 16 linkage groups (LG), and covers a total length of 1701 cM, with an average marker spacing of 8.2 cM. Using 96 homologous loci, we also demonstrated the high level of macrosynteny with the genome of A. bisporus. The 13 main LG of A. subrufescens were syntenic to the 13 A. bisporus chromosomes. A disrupted synteny was observed for the three remaining A. subrufescens LG. Electronic mapping of a collection of A. subrufescens expressed sequence tags on A. bisporus genome showed that the homologous loci were evenly spread, with the exception of a few local hot or cold spots of homology. Our results were discussed in the light of Agaricus species evolution process. The map provides a framework for future genetic or genomic studies of the medicinal mushroom A. subrufescens.

Genetic Analyses of the Internal Transcribed Spacer Sequences Suggest Introgression and Duplication in the Medicinal Mushroom Agaricus subrufescens

“…bisporus . This result indicated that the position of PR160 and/or of the ITS locus likely differed between these two species, despite their high level of macro-synteny [ 28 ]. In strain CA487, ITSI is most likely functional because offspring having only the ITSI-a or the ITSI-b alleles are viable.…”

“…bisporus homolog was close to MAT and the centromere (PRS088 marker), and its tight linkage with the centromere was recently confirmed in A . subrufescens [ 26 ] and more generally a highly conserved macro-synteny between the two species [ 28 ]. Then, two other A .…”

Comparative and population genomic landscape of Phellinus noxius: A hypervariable fungus causing root rot in trees

“…Here, we report four high‐quality genome sequences of Hymenochaetales species that are global tree pathogens of particular importance. To date, chromosome‐level assemblies are available only for a few basidiomycetous species (Alfaro et al., ; Foulongne‐Oriol et al., ; Stajich et al., ) including P. noxius (Table ). Orthologous relationships with other complete genomes of basidiomycetes have confirmed conservation of karyotypes with few fusion or breaks in Agaricomycetes.…”

Recombination suppression and evolutionary strata around mating‐type loci in fungi: documenting patterns and understanding evolutionary and mechanistic causes

“…Another factor that may be relevant to the recombination landscape is that the BSN locus (basidial spore* number), determining the number of nuclei per dispersing spore* and thus the automictic* versus outcrossing behaviors, is linked to the mating‐type locus (Imbernon et al ., 1996). Within the Agaricus genus, the recombination suppression around the mating‐type locus also has been reported in the distant species A. subrufescens (Thongklang et al ., 2014; Foulongne‐Oriol et al ., 2016) and A. sinodeliciousus (Ling et al ., 2019). In A. subrufescens , a genetic linkage map suggested a normal recombination behavior on the rest of the genome (Foulongne‐Oriol et al ., 2016).…”