Analyses of the A and B mating-type locus structure from Naematelia aurantialba based on genomic data
Naematelia aurantialba,a rare jelly edible fungus of the Tremellales order,is endemic to China and is often used as traditional medicine and food due to its exceptional nutritional value and biological activity.It is a heterothallic basidiomycete with a tetrapolar mating system.However,the structures of mating loci have not been characterized.In this study,the genome of four different mating types of monokaryotic strains of N.aurantialba was sequenced by second generation sequencing technology,and mating type A and B loci were searched and compared with those of other macrofungi by bioinformatics method based on genomic data.The results showed that there were two A mating-type loci and two B mating-type loci in these monokaryons.All two A mating-type loci contain a pair of HD1 and HD2 genes arranged in a typical'head-to-head'manner and the synteny of several genes'upstream and downstream of A loci was higher as compared with that of other fungi,including conserved Oxidoreductase and PRL22 genes.However,the mip and β-fg genes are not closely linked to the HD gene and are not located on both sides of it.All two B mating-type loci contain a pheromone receptor and a pheromone precursor gene.Upon comparison of the B1 and B2 loci,it was discovered that the STE3 and phB genes at the B1 locus were situated in close proximity with one RVT_1 gene located upstream of phB.In contrast,at the B2 locus,three genes were inserted between the STE3 and phB genes,and the STE12 gene was absent from the B1 locus.Compared with B loci in other fungi,the synteny of B loci was poor,indicating that B loci were highly variable in different fungi.The gene for the pheromone receptor NaSTE3-3 is present in all four monokaryons,however,the gene for the pheromone precursor is not located in upstream or downstream,and the B mating type site is not present on the same contig.These results obtained would help us to understand the mating locus structures of N.aurantialba,being helpful to genetic breeding of this mushroom.
Naematelia aurantialbamonokaryotic straingenomeA mating type locusB mating type locussequence analysis
万方数据
维普
