mycetozoa domain eukarya kingdom protista phylum mycetozoa

Mycetozoa

Domain Eukarya

Kingdom Protista

Phylum Mycetozoa

Looking Back at Bio 115The Organism as a Unit of Life

Cellular Structure (cell = unit of life)…one or many!

Metabolism = Homeostasis (PSN, Resp, N2fix, ferment, etc.)

Growth = irreversible change in size

Reproduction…failure = extinction

Acclimatization-short term responses = behavior

Adaptation-long term responses = evolution

Shifting Kingdoms2 3 5 6 8

Bacteria Bacteria Bacteria Bacteria Bacteria

Archaebacteria Archaebacteria Archaebacteria Archaebacteria Archaebacteria

Archezoans Archezoans Archezoans Archezoans Archezoans

Euglenoids Euglenoids Euglenoids Euglenoids Euglenoids

Chrysophytes Chrysophytes Chrysophytes Chrysophytes Chrysophytes

Green Algae Green Algae Green Algae Green Algae Green Algae

Brown Algae Brown Algae Brown Algae Brown Algae Brown Algae

Red algae Red algae Red algae Red algae Red algae

Slime Molds Slime Molds Slime Molds Slime Molds Slime Molds

True Fungi True Fungi True Fungi True Fungi True Fungi

Bryophytes Bryophytes Bryophytes Bryophytes Bryophytes

Tracheophytes Tracheophytes Tracheophytes Tracheophytes Tracheophytes

Protozoans Protozoans Protozoans Protozoans Protozoans

Myxozoans Myxozoans Myxozoans Myxozoans Myxozoans

Multicellular Animals





Lumpers SplittersPlantae Fungi Protista

How Many Kingdoms?

Mul

ticell

ular

Animals

Myx

ozoa

ns

Proto

zoan

s

Trache

ophy

tes

Bryop

hytes

True F

ungi

Slime M

olds

Red al

gae

Brown A

lgae

Green A

lgae

Chrys

ophy

tes

Euglen

oids

Archez

oans

Archae

bacte

ria

Bacter

ia

Original Cell

Extant

Extinct

Long Time with

Prokaryotes only

8

5

3

2

1

Protista appears

Protista refined

Still needs refining!

Mycetozoans

• “True and Cellular Slime Molds”

• Somewhere between protists and fungi Predatory amoeboid feeding upon bacteria, usually in decaying

material

Engulfing feeding

Reproduction via spores

• 500 species

• Two Major Classes:1. Myxogastrea (True slime molds: Physarum)2. Dictyostelea (Cellular slime molds: Dictyostelium)

Physarum polycephalumTrue Slime Mold

Haploid (1N) spores germinate in rotting vegetation

Flagellated gametes emerge and undergo syngamy

Diploid (2N) zygote amoeboid cell feeds on bacteria

Mitosis without cytokinesis makes multinucleate plasmodium

Cytoplasm migrates by streaming

Develops into fruiting body undergoing meiosis to make haploid spores

http://botit.botany.wisc.edu:16080/images/332/Slime_molds_M_Ac_sl_so/Physarum_folder/Physarum_plasmodium_I_TJV.gif

http://bic.usuf1.usuhs.mil/Mark/Images/OgiharaEM01.jpg


This portion of the plasmodium is showing the amoeboid movement of the cytoplasm.

The plasmodium engulfs bacteria by endocytosis into food vacuoles for digestionFood

VacuolesNuclei The plasmodium is

multinucleate, and each nucleus is diploid (2N).

QuickTime™ and aPhoto - JPEG decompressor

are needed to see this picture.

http://botit.botany.wisc.edu/courses/img/Botany_130/Movies/Slime_mold.mov


The plasmodium with all of those nuclei and food vacuoles, etc. shows amazingly active cytoplasmic streaming shown in this movie.

The movement involves actin-myosin interactions between microfilaments of actin and myosin proteins bound to organelles.

The movement relies upon Ca2+ and ATP availability.

http://www.botany.hawaii.edu/faculty/wong/Bot201/Myxomycota/Physarum_Sporangium.jpg


Looking at this sporangium, can you figure out how the specific epithet was inspired?

Sporangium

Sporangiophore

http://www.bioimages.org.uk/MMWSt/PixM.7xs/2000/00-10/00-10-17/00J17E+E.jpg

Spores

http://www2.una.edu/pdavis/physamb.jpg

Spore

Zygote

Gametes


The spores germinate, releasing flagellated gametes.

The gametes unite in syngamy.

The resulting zygote is amoeboid and begins feeding.

Mitoses without cytokinesis enlarges the multinucleate zygote into a full plasmodium.

Tipula oleraceae or T. paludosaAdults resemble mosquitoes because they are indeed relatives.

Adults generally do not feed and live for only a few days.

The larval stages are aquatic in some species or lawn soil dwelling in other species.

http://whatcom.wsu.edu/cranefly/faq.htm

adult

eggs

larva

pupa

adult

Life Cycle of Physarum polycephalum

plasmodium

sporangium

cytokinesis

SYNGAMY

MEIOSIS

zygote

SporophyteGametophyte

sporangium

sporocytespores

gametangia

gametesgermination

mitosis

differentiation

mitosisgerminationmitosis

differentiation

differentiation

mitosis

1N 2N

4 meiospores

myxamoebae

isogametes

swarm cells

differentiation

no cytokinesis

asexualreproduction mitosis

This is basically the gametic shortcut… spores become gametes… if the mitosis of myxamoebae is not considered equivalent to the production of a multicellular gametophyte.

sporocyte

http://www.rinshoken.or.jp/org/EM/spore.jpg

Dictyostelium discoideumCellular Slime Mold

This is the spore produced by the sporangium.

Actin rods extend the length of the spore.

It is released into the wind and carried to hopefully-better environments.

There it germinates to produce amoebae.


The amoebae feed upon bacteria.

http://dicty.cmb.nwu.edu/chisholm/chisho2.jpg

http://www.nigms.nih.gov/research/images/dicty.jpg

http://www.biologie.uni-hamburg.de/b-online/d27_10/agg290.jpg

OHO

O

O-

OO

OP

N

NH2

N N

N

Adenine

Ribose

When the bacterial supply is gone, one amoeba produces cAMP.

This signals others to join together to form a multicellular pseudoplasmodium (“slug”).

http://csep10.phys.utk.edu/krogh_instructorCD/biology/ImageBank/Unlabeled/CH20/uFG20_10.jpg


The pseudoplasmodium moves on a slime trail seeking more bacteria.

If bacteria are not found, the plasmodium differentiates into sporangiophore and sporangium.http://www.axxon.com.ar/zap/208/MohoMucoso.jpg


The amoebae feed upon bacteria.

When the bacterial supply is gone, one amoeba produces cAMP, signalling the others to join together to form a multicellular pseudoplasmodium (“slug”).

The slug moves on a slime trail seeking more bacteria.

If bacteria are not found, the plasmodium differentiates into sporangiophore and sporangium.

The spores are shed to the wind to disperse the species.

http://www.bio.ic.ac.uk/research/tps/images/fig4.gif

mycetozoa domain eukarya kingdom protista phylum mycetozoa

Documents

dictyostelium slide

sporocyte slide

evolution slide

sop slide

n spores

bacteria mitosis

myxogastrea true slime

slime trail