division: rhodophyta - university of california, santa cruz · pdf fileherbarium assignment:...
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Important Dates May 9- Practical I & Notebooks Due: - Study your notebook - most algae you've already seen - know your phycologist terms - bring your MAC - microscope section - matching section - 2 unknowns - turn in notebooks & MAC to TA at start of lab - labs 1-5 graded - 3 hours - AM lab starts at 9 AM!!! May 12- next Monday Presentation Paper Due May 28- Presentation Question Due
University of California, Santa Cruz
ALGAE OF Chlorophyta, Cladophorales
Name Acrosiphonia coalita (Ruprect) R.F. Scagel, D.J .
Garbary, L.Golden & M.J.Hawkes
Location Davenport Landing , Santa Cruz, California
Habitat found in low intertidal, growing on rocks
Collected by your name Date April 19, 2014 No. 1
Identified by your name Date April 19, 2014
Heterokontophyta Incertae sedis
Phaeostrophion irregulare Setchell & N.L. Gardner
Herbarium assignment: current name: http://ucjeps.berkeley.edu/californiaseaweeds.html
current order: http://www.algaebase.org/
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Division: Rhodophyta
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DOMAIN 1.Bacteria- cyanobacteria (blue green algae)
2.Archae 3.Eukaryotes
Groups (Kingdom) 1. Alveolates- dinoflagellates 2. Stramenopiles- diatoms, heterokonyophyta 3. Rhizaria- unicellular amoeboids 4. Excavates- unicellular flagellates 5. Plantae- rhodophyta, chlorophyta, seagrasses 6. Amoebozoans- slimemolds 7. Fungi- heterotrophs with extracellular digestion 8. Choanoflagellates - unicellular 9. Animals- multicellular heterotrophs
“Algae”
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Photosynthetic organisms on earth 3.45 bya = Cyanobacteria appear and introduce photosynthesis 1.5 bya = first Eukaryotes appeared (nuclear envelope and ER thought to come from invagination of plasma membrane) 0.9 bya = first multicellular algae (Rhodophyta - Red algae) 800 mya = earliest Chlorophyta (Green algae) 400-500 mya = plants on land – derived from Charophyceae 250 mya = earliest Heterokontophyta (Brown algae) 100 mya = earliest seagrasses (angiosperms)
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Division Rhodophyta
- most speciose of the macroalgae
Location S. Australia N. Atlantic CA Red 800 (70%) 589 (50%) 459 (69%) Brown 231 324 137 Green 123 258 72 1154 1171 668
> 6,500 species total 98% marine
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Biogeography/distribution • Found at all latitudes
• Temperate / Tropical highest # of spp (outnumber browns and greens)
• Polar
relatively few species – browns and greens dominate lots of crustose coralline reds, to 200 m
• Size distribution
tropical = mostly small filamentous plants (except calcareous forms) temperate = larger fleshy species
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1) Pigments: chl a carotenoids: phycobilins:
2) Chloroplast structure:
• envelope: layers • thylakoids: single, no stacks
3) Storage product: s
4) Flagella: n
5) Mitosis:
Rhodophyta Characteristics
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Hierarchical system of classification: Level: suffix: example: Domain Eukaryote Group Plantae Division -phyta Rhodophyta Class -phyceae Florideophyceae Subclass -phycidae Rhodymeniophycidae Order -ales Rhodymeniales Family -aceae Rhodymeniaceae Genus Rhodymenia species pacifica
Algal taxonomy
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Phycobilisome structure:
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Pigments
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Structure of phycoerythrin + protein
Phycobilisome on thylakoid membrane
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…vs. other divisions: pigments imbedded within the thylakoid membrane
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Reds respond to changing light conditions by: 1. Changing the number/density of phycobilisomes
2. Changing the # of molecules of pigment in each antennae …what is this called?
Rhodophyta Pigments
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Buoy
Pigments Experiment: - same species of red algae - place on rope at 3 depths
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Buoy
PC
PE
Pigments Experiment: - same species of red algae - place on rope at 3 depths
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Two Main Components: 1. Cellulose microfibrils
Function: structural support
2. Phycocolliods- Mucilaginous polysaccarides
surrounds the microfibrills a. agar (agarose) b. carageenan
Function: elasticity; flexibility; prevent
desiccation; and osmoregulation (ion exchange) (“carageenan” after Irish county where Chondrus crispus is found)
Rhodophyta Morphology of Cell Walls
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Human Uses of Rhodophyta
• Food • nori (Porphyra) • 1949 life cycle completed – advanced cultivation techniques
• Phycocolliods = dervived from mucilagenous polysaccharides of cell walls
•Thickeners •Stabilizers •Gels
•Two important phycocolliods: • Carageenan (toothpaste, cosmetics, chocolate milk, ice cream, dessert gels, pet foods), found in Chondrus, Gigartina, Eucheuma and Kappaphycus •Agar (food gel, pharmaceutical capsules, medium for culturing microorganisms, gel electrophoresis) , found in Gelidium, Gracelaria, Pterocladia, and Ahnfeltia
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Rhodophyta Cell Characteristics: large cells due to:
1. Multinucleate = one cell has multiple nuclei # of nuclei correlated to the number of plastids (replication, mitosis, no cytokinesis) 2. Polyploidy- repeated genome duplication buffer against mutation of essential genes (Endoreduplication = replication, no mitotic nuclear division)
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Apical cell:
Derived
cells:
Cell characteristics
Multinucleate non- polyploid
Uninucleate non- polyploid
Uninucleate polyploid
Uninucleate non- polyploid
Multinucleate non-polyploid
Uninucleate polyploid
Multinucleate non- polyploid
Multinucleate non- polyploid
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Uninucleate, polyploid
Cell characteristics
Apical cell:
Derived cells:
Examples:
Multinucleate non- polyploid
Polysiphonia
Multinucleate, non- polyploid
Microcladia Mazzaella, Callithamnion, Chondracanthus
Uninucleate polyploid
Uninucleate non- polyploid
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• Spores – no flagella
• Gametes – no flagella
• “spermatia” = unflagellated male gamete; no free movement
• Passive dispersal by water
Flagella? NO- lack of flagella has led to TRIPHASIC LIFE HISTORY
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Pit plugs - structural support between cells
Old name: “pit connections” • Protinaceous plugs between cells
• Primary pit plugs formed during cytokinesis between 2 daughter cells within a filament
• Not a real connection – unlike browns, not for transport
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• Secondary pit plugs formed between non-related cells within and individual among filaments or between individuals (parasites)
Pit plugs - structural support between cells
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-Unicellular- solitary non motile cells
- Filamentous- chain of cells -Parenchymatous- undifferentiated, isodiometric cells generated by a meristem
- Pseudoparenchymatous- form of thallus composed of interwoven continuous filaments
Rhodophyta Morphology
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Polysiphonous – composed of tiers of vertically elongated cells, transversely arranged, the lateral cells around a central axis (siphon)
central filament surrounded by 4 or more pericentral cells MAC Key: Cells in a regular transverse series
Polysiphonia
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Cortication – elaboration of polysiphonous condition where pericentral cells continue to proliferate
Morphology
Partial Cortication 28
Reds often display growth through cell elongation
Growth
New growth = not florescent
Cell repair by cell fusion
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– filamentous growth in 2 directions, results in thallus composed of both prostrate + erect components
Heterotrichous Growth
= cell division
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Uniaxial Growth- one longitudinal central filament forming the axis
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Multiaxial Growth- several longitudinal medullary filaments, each derived from an apical cell
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Division: Rhodophyta- 6504 species
Eight classes Focus on 3 classes: 1. Class: Porphyridiophyceae -12 species 2.Class: Bangiophyceae-158 species 3.Class: Florideophyceae- 6,199 species
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Division: Rhodophyta- 6504 species 1. Class: Porphyridiophyceae -12 species Order: Porphyridales
• Unicellular
• “a little round thing”
• Soil, Arial habitats, Fresh water, Brackish, Marine
•Surrounded by a mucilaginous sheath • Large stellate chloroplast
• Reproduction by cell division, release of vegetative cells or by endospores Genus: Porphyridium, Rufusia 34
Division: Rhodophyta- 6504 species Class: Porphyridiophyceae -12 species Order: Porphyridales Genus: Porphyridium
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Division: Rhodophyta- 6504 species 1.Class: Porphyridiophyceae -12 species Order: Porphyridales Genus: Rufusia
Found only in sloth hair
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- “simple” reds
- unicells, filaments, parenchymatous blades
- marine, terrestrial, freshwater
- uninucleate
-one stellate chloroplast per cell
- pit plugs rare; if present, only primary, and in 2N stage
- biphasic life history
Division: Rhodophyta- 6504 species 2.Class: Bangiophyceae-158 species Order: Bangiales
Genus: Bangia & Pyropia
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Genus: Bangia
• Unbranched uniseriate filament in early development; later becomes multiseriate; rhiziodial extensions of lower cells •2N conchocelis stage like Porphyra
•Asexual reproduction by monospores
• Pit plugs present in conchocelis stage but not in gametophyte
•Inhabits upper intertidal splash zone on rocks – rarely epiphytic
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Genus: Pyropia (Porphyra) 1N gametophyte: parenchymatous blade monostromatic or distromatic
2N sporophyte: “conchocelis” stage discovered in 1949 by Kathleen Drew Baker REVOLUTION microscopic filament lives on/in mollusk shells perennial
• Haplodiplontic life history • Saxicolous or epiphytic • Harvested for nori
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Algal Life Histories :Terminology
Spermatium, spermatia (pl) = a non motile cell that functions as a male gamete
Carpogonium = female gamete
Conchocelis stage= 2N filamentous stage; lives in/on CaCo3 shells of mollusks
Conchospore = 1 N spore produced by 2N conchocelis stage
Monospore= asexual spore that develops into the same phase as the parent
Asexual vs. Sexual: gametophyte switches from monospores to gametes; triggered by daylength (fall = shorter days = sex)
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fertilization
Division: Rhodophyta- 2.Class: Bangiophyceae- Order: Bangiales
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Life Cycle of the BangialesHaplo-diplontice.g. Porphyra gardneri
2N carpospores
syngamy
carpogonium
spermatium
meiosis occurs inconchosporangium
microfilamentous2N conchocelis stage
1N conchospore
monospore
plantlet
1Ngametophyticmacrothalli
Life History of Bangaliales ex Pyropia
Haplodiplontic Alternation of Generations: organism having a
separate multicellular diploid sporophyte and haploid gametophyte stage
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- advanced reds
- always multicellular: filaments or psuedoparenchymatous
-marine, freshwater
-almost always multinucleate
-many discoid chloroplasts
-primary and secondary pit plugs
- triphasic life history
Division: Rhodophyta- 6504 species 3.Class: Florideophycidae-6199 species
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Triphasic Life History 1) Gametophyte: haploid, 1N multicellular releases gametes 2) Carposporophyte: all 2N material on the female gametophyte where the 2N zygote is cloned to form the carpospores releases carpospores 3) Tetrasporophyte: diploid, 2N multicellular releases tetraspores
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1N gametophytes
mitosis
2N carposporophyte on 1N female gametophyte
2N
1N
growth
2N
1N
1N
Carpogonium on a carpogonial branch
Multiple 2N carpospores produced through mitosis in gominoblast filaments
2N carpospores
meiosis
1N tetraspores
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Triphasic Life Histories :Terminology
Female Gametophyte-hapliod, 1n, multicellular produces gametes
Carpogonial branch (cb)= filamentous branch on which the carpogonium are formed
Carpogonium (cp) =female gamete
Trichogyne = extension of egg to which spermatium attaches
Male Gametophyte-hapliod, 1n, multicellular release gametes
Spermatangial branch = filamentous branch which holds the spermatangia
Spermatangium, Spermatangia-male reproductive structure that produce spermatia
Spermatia= male gamete
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Female gametophyte - Polysiphonia
Male gametophyte - Polysiphonia
Triphasic Life Histories :Terminology
Trichoblast = usually a uniseriate filament of cells (with little pigmentation) that either remains sterile or can undergo division to form either spermatangia or carpogonium.
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1N gametophytes
mitosis
2N carposporophyte on 1N female gametophyte
growth
2N
1N
1N
2N
1N Carpogonium on a carpogonial branch
Multiple 2N carpospores produced through mitosis in gominoblast filaments
2N carpospores
meiosis
1N tetraspores
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Carposporophyte = diploid, multicellular, one of the 2N generations; develops from the fusion of the carpogonium & spermatium (all 2N material on the female gametophyte); this is where the 2N zygote is cloned to form the carpospores
Pericarp = 1N vegetative tissue that surrounds the carposporophyte
Cystocarp = pericarp (1N) + carposporophyte (2N).
Carposprorangia = reproductive structures that produce carpospores
Gonimoblast = 2N filaments bearing carposporangia in the carposporophyte
Carpospore = dipliod (2n) spore formed by mitosis by the carposprophyte
Triphasic Life Histories :Terminology
2N
1N
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49 2N tetrasporophyte
1N gametophytes
mitosis
2N carposporophyte on 1N female gametophyte
2N
1N
growth
2N
1N
1N
Carpogonium on a carpogonial branch
Multiple 2N carpospores produced through mitosis in gominoblast filaments
2N carpospores
meiosis
1N tetraspores
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types of tetraspore arrangement within the tetrasporangia (four 1N spores)
Zonate Cruciate (two views) Tetrahedral
Tetrasporophyte = diploid, multicellular, one of the 2n generations; develops from
germinating carpospore & release tetraspores
Tetrasporangium = 2N cell which undergoes meiosis to form 4 tetraspores
Tetraspore = haploid (N) spore formed by meiosis by the tetrasporophyte
Triphasic Life Histories :Terminology