Life Cycles of Myxogastria Stemonitopsis typhina and Stemonitis fusca on Agar Culture

Abstract

Myxogastria is a group of protozoa characterized by cellular uninucleate amoeboflagellates (myxamoebae and flagellated swarm cell), acellular multinucleate plasmodia, and stationary spore‐bearing sporocarps. The Stemonitales is a large order in the Myxogastria and contains approximately 230 species, but only 13 species have their completed life cycles observed so far. Here, we described the life cycles of two species in Stemonitales, Stemonitopsis typhina and Stemonitis fusca by culturing in water agar medium and observing the morphogenesis of their spore germination, plasmodium, and sporocarp development. The spore‐to‐spore life cycles of Ste. typhina and S. fusca were completed in approximately 67 and 12 d, respectively. Both species possessed an aphanoplasmodium. However, the spores of Ste. typhina and S. fusca germinated by the V‐shape split and pore methods, respectively. Unlike S. fusca with an evanescent peridium, Ste. typhina produced a shiny persistent peridium which was continuous with the membrane surrounding its stalk. The information will contribute to a better understanding of their taxonomy and phylogeny.

Isolation and Genome Analysis of an Amoeba-Associated Bacterium Dyella terrae Strain Ely Copper Mine From Acid Rock Drainage in Vermont, United States

“…The latter had one or two flagella from one pole of the cell, which were roughly 7 μm in diameter. Similar to Stemonitis fusca , we observed transparent, rounded, and irregular shaped flagellated protoplasts 7.5–10 μm in length ( Dai et al, 2020 ). The 18S rRNA gene sequence had a best hit (e-value = 2E-120) corresponding to a member of the Amoebozoa supergroup, Stemonitis sp., with 99.79% identity (see phylogeny in Supplementary Figure 1 ).…”

“…While we only observed unicellular and flagellated states, the composition of our media could explain the absence of plasmodia and sporocarps, as the formation of plasmodia and sporulation commonly occur on water- or oat-agar surfaces ( Dai et al, 2020 ). Temperature, pH, numbers of cells, and the duration of photoperiods are also important variables that affect how plasmodial slime molds complete their life cycles ( Gao et al, 2017 ; Zhu et al, 2019 ; Dai et al, 2020 ). Determining the Stemonitis life cycle will be important for further characterization, as species in Myxogastria are classically identified by the structural characteristics of their sporocarps and plasmodia ( Clark and Haskins, 2014 ).…”

“…are slime molds with unique characteristics, such as a spore-to-spore life cycle, and commonly found on decaying plant matter in terrestrial ecosystems ( Stephenson and Stempen, 1994 ). Depending on growth conditions, they can be found as cellular uninucleate amoeboflagellates, acellular multinucleate plasmodia, and stationary spore-bearing sporocarps ( Dai et al, 2020 ). While we only observed unicellular and flagellated states, the composition of our media could explain the absence of plasmodia and sporocarps, as the formation of plasmodia and sporulation commonly occur on water- or oat-agar surfaces ( Dai et al, 2020 ).…”

“…Depending on growth conditions, they can be found as cellular uninucleate amoeboflagellates, acellular multinucleate plasmodia, and stationary spore-bearing sporocarps ( Dai et al, 2020 ). While we only observed unicellular and flagellated states, the composition of our media could explain the absence of plasmodia and sporocarps, as the formation of plasmodia and sporulation commonly occur on water- or oat-agar surfaces ( Dai et al, 2020 ). Temperature, pH, numbers of cells, and the duration of photoperiods are also important variables that affect how plasmodial slime molds complete their life cycles ( Gao et al, 2017 ; Zhu et al, 2019 ; Dai et al, 2020 ).…”

Life cycle and plasmodial axenic culture of Physarum galbeum

“…Until now, 102 Myxogastrea species have been grown from spore-to-spore in laboratory culture, not including species with life cycle finished but not recorded in literature [7,8]. Only 20 species have been grown axenically [9][10][11].…”