Mucor (= Zygorhynchus) heterogamous
Vuill. NRRL 1489 is a homothallic or self-fertile zygomycete fungus
classified in the family Mucoraceae [Order Mucorales; Hesseltine et
al. 1959]. Recent molecular phylogenetic analyses of the
nuclear ribosomal internal transcribed spacer region (ITS rDNA) and
partial nuclear ribosomal large subunit (LSU rDNA) sequences
revealed that Zygorhynchus is polyphyletic and not
phylogenetically distinct from Mucor (Walther et al.
2013). Consequently, the genus Zygorhynchus was
abandoned and all of the species were reclassified in
Mucor. The eight homothallic species within this
group are most commonly found in diverse soils in both hemispheres
(Domsch et al. 1980). The now abandoned genus
Zygorhynchus was distinguished originally from
Mucor by the following combination of characters:
formation of spherical multispored sporangia (Fig.
1A), a sporangial wall that deliquesces at maturity,
revealing a columella (Fig. 1B), and brown to
black, ornamented zygospores formed between suspensors that differ
greatly in size (Figs. 1C-D). Whole genome
sequencing of M. heterogamous will advance the 1000 Fungal Genome
Project by providing a representative of the Mucoraceae, and
additional insight into the evolution of the mating type locus in
early diverging fungi.
References:
1) Domsch KH, Gams W, Anderson T-H. 1980. Compendium of Soil
Fungi. Academic Press, New York.
2) Hesseltine, C.W., C.R. Benjamin, and B. S. Mehrotra. 1959. The
genus Zygorhynchus. Mycologia 51:173‒194.
3) Walther G, Pawlowska J, Alastruey-Izquierdo A, Wrzosek M,
Rodriguez-Tudela JL, Dolatabadi S, Chakrabarti A, and de Hoog GS.
2013. DNA barcoding in Mucorales: an inventory of biodiversity.
Persoonia 30:11‒47.