Understanding Reproduction in Chytridiomycota

Martha J. PowellThe University of Alabama

But mostly asexually

How do They Do It?

Asexual Reproduction in Chytridiomycota

Asexual reproduction

zoospores in sporangiaautospores in sporangiafragmentation- polycentrics and

resting spores

Some resting spores (resting sporangia) my arise asexually

Vegetative stage is haploid

Asexual Life Cycle

Pollen

Zoospores

Septosperma sp. Resting Spores

Fragmentation

Powell & Blackwell 1991

Inoperculate Discharge

1% Toluidine Blue

Powell 1976

“Operculomyces sp.” JEL 223

Operculate Discharge

Sexual Reproduction in Chytridiomycota

Recombination has been reported via multiple techniques

Oogamous with motile spermPlanogametic copulationSomatogamy = rhizoidal fusionGametangial contact & copulation

Verification more limited

Meiosis is zygotic

Resting Spores Arise Asexually and Sexually

Thick Wall

Lipids

Glycogen

Reduced hydration

Germination typically prosporangium

Monoblepharis

MonoblepharidomycetesOogamous with motile sperm

Sparrow 1933 Shanor 1942

Marek 1984

ChytridiomycetesSomatogamy = rhizoidal fusion

Chytriomyces hyalinus MP004

Chytriomyces hyalinusMP 004

> 7 days

> Viewed on PmTg agar

> 10X and 20 X

CT

Resting spores are small

Can also form asexually

SomatogamyChytriomyces hyalinus

Moore and Miller 1973

Miller 1977

Polyphagus euglenae

Gametangial contact

Wager 1913

Polyphagus euglenae

Gametangial copulation

Canter 1967

Doggett and Porter 1996

Zygorhizidium planktonicum

Concepts

• Individuals – asexual versus sexual

• Nutritional stress

• Survival strategysizehydration (hydrolytic enzymes)storage

Thanks to National Science Foundation

• PEET Award #0529694Phylogenetic and Monographic Research on Spizellomycetalean Chytrids (Chytridiomycota)

• PEET Award #9978094 Monographic Research on the Zoosporic Fungi, Chytridiomycetes