Mycetozoa Domain Eukarya Kingdom Protista Phylum Mycetozoa.
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Transcript of 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
Multicellular Animals
Multicellular Animals
Multicellular Animals
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
Physarum polycephalumTrue Slime Mold
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
Physarum polycephalumTrue Slime Mold
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
Physarum polycephalumTrue Slime Mold
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
Physarum polycephalumTrue Slime Mold
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.
Dictyostelium discoideumCellular Slime Mold
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
Dictyostelium discoideumCellular Slime Mold
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
Dictyostelium discoideumCellular Slime Mold
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