On the cover of this week’s Nature is a picture of Phycomyces blakesleeanus highlighting the discovery of the MAT locus in this Zygomycete fungus from Alex Idnurm and Joe Heitman and colleagues. While it was previously known that Zygomycetes (the Orange lineage represented by R. oryzae in the tree below) mate, the specific locus has until now, never been discovered. The authors in this study identified the MAT locus through a sequence search looking for HMG-box genes knowing that these are found the Mating Type locus in Basidiomycetes and Ascomycetes. They confirmed the identity through a through set of experiments that included PCR, sequencing and crosses of (+) and (-) strains of P. blakesleeanus, and Southern blots.
I recently heard through the grapevine that the Mucor ircinelloides genome 4X assembly was completed by JGI and a BLAST server is available if you contact the authors. Mucorales (previously Zygomycota which is not monophyletic) includes previously sequenced Rhizopus oryzae and Phycomyces blakesleeanus which we’ve blogged about before.