Figures 1a, b. a). Typical umbellately arranged fertile head showing the asexual reproductive structures arranged in a coemansioid pattern and vegetative mycelium coiled around hyphae in the colony. b). Typical coemansioid arrangement of the sporocladial stipe (ss), septate sporocladium (sc), pseudophialides (p) and merosporangiospores (s). Fig. 1a = 20 x, Fig. 1b = 100 x. Credit: Gerald Benny, Matthew Smith.

Martensiomyces pterosporus J.A. Mey., strain CBS 209.56

Martensiomyces pterosporus is a saprotrophic member of the Kickxellaceae. This rare fungus has only been isolated one time from soil collected in Yangambi, Congo, now the Democratic Republic of the Congo.  In culture M. pterosporus produces a bright yellow, low, up to 2 mm high, colony.

Martensiomyces represents one of twelve genera currently included in the Kickxellaceae and its ecological role in soil ecosystems is still unknown.

The systematics of the family Kickxellaceae is based largely on the morphological characteristics of the mycelium. The vegetative mycelium of all representatives of Kickxellaceae form characteristic 1-spored or 2-spored merosporangia, which serve as organs of asexual reproduction.  Zygospores (sexual spores) have never been seen in Martensiomyces pterosporus. The arrangement of the fertile head (umbellate  origin of the sporocladial branches) in Martensiomyces is unique and distinct from species in other genera of Kickxellaceae. The hyphae of Martensiomyces also have a septal pore with a plug in a lenticular cavity.

In addition to providing new information about the evolutionary relationships within the Kickxellomycotina, sequencing the genomes of members of the Kickxellaceae will also help to elucidate the ecological roles that these fungi play in nature. The acquisition of a septal plug apparatus that helps to control cytoplasmic movements between cells has been a key innovation within some groups of fungi. Accordingly, the genome of Martensiomyces pterosporus will likely provide important clues for understanding more about the evolution and function of this cellular apparatus.