Slime Molds

Slime Molds…WhateverDarrin Rubino

Hanover College Biology Department

Overview• What they are• What makes them unique• Life History and Ecology• Research• Conclusions

Slime Molds• Unfortunate name• Four different types of organisms• Protists (more or less)• Amoebozoa (kingdom)• Phylum Myxomycota– Myxomycetes (Class)– True slime molds– Acellular slime molds– Plasmodial slime molds

• Biological jewels

Slime Molds

• So bizarre, long misclassified• Long thought to be a fungi– myxa– mycetes

• Phylogenetic placement– Molecular– Developmental

• Own kingdom• Must understand life cycle to appreciate

Life cycle• Very unique• “Extravagant” life history• Does reproduce sexually (earliest protists)• Variable among species• General– Plasmogamy - join protoplasts– Karyogamy – fusion of nuclei– Meiosis

• Ploidy of structure

Plasmodium

• Incredible stage of lifecycle• Acellular – multinucleate (millions)– Synchronous– 8 – 10 hours

• Fluid and gelatinous • Streaming 1.35 mm/s• http://www.youtube.com/watch?v=UKSGAHAfWis

Plasmodium

• Phagotrophs– Bacteria– Yeast– Fungal spores– Decaying matter

• Expand while favorable conditions

• Declining conditions• http://

www.youtube.com/watch?v=p6OoHctERPs

Classification• Approximately 888

different species • Much variation• Class: Myxomycetes• Three subclasses• Six orders

Sporophore developmentSporophore typeSpore productionSpore colorCapillitiaCalcium or lime

1 mm

1 mm

Chocolate tube slimeStemonitis fusca

Yellow-fuzz cone slimeHemitrichia clavata

1 mm

Red raspberry slimeTubifera ferruginosa

Multigoblet slimeMetatrichia vesparium

1 mm

Life History and Ecology• Are these things common?• Did I ever even see one?• Very common in temperate forests

caca de luna

Enteridium lycoperdon

Life History and Ecology

• “…superficial and largely qualitative” (Ing)• Cosmopolitan• Requirements– Moisture– Temperature– Substrate– pH

Life History and Ecology

• Specialists – Assemblages – Bark

• Seasonal – Spring through October– October is peak

• Much more to be learned

Research Avenues

• Moist chamber technique• Physarum polycephalum

Current Research

• Synchronization of cell division• Senescence• Cancer

• Purified Poly(b-L-malic Acid)• Polycefin (polycephalum)• Deliver antisense gene silencing

therapies

CytologyGeneticsMolecular biologyBiochemistryBiophysicsMitosisMorphogenesisReproduction (cue)PhysiologyAging

Current Research

• Heavy metal clean up– Dog barf slime– Potential plant GMO

• Space – gravity sensing• Novel biological compounds– Trials necessary– Not just novelties (Keller)

Conclusions

• Unique protists• Few specialists (disease & economic impact)• Still much to learn– Application health/environment– Ecology

• Questions