Lecture 2: Common red algal families in the vicinity of Bocas del Toro: Gracilariaceae

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Lecture 2 Common red algal families in the
vicinity of Bocas del ToroGracilariaceae
Photo O.Camacho Hadad Anna Fricke
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Gracilariaceae
Rhodymeniaceae
Halymeniaceae
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family, ordinal level
flat sp.
vegetative structure cellular medulla
Gracilaria
terete sp.
Hydropuntia
mixed-sized cells
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Solieriaceae
Gracilariaceae
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Solieriaceae (Solieria)
loose filiform, or mixed cellular-filiform
medulla
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Halymeniaceae (Cryptonemia)
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2
1
2
3
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-cortical unit of 3 surface cells
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Conjunctor cells fuse with neighboring cells,
resulting in secondary pit connection formation
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-inherently uniaxial
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-uniaxial growth quickly disguised -axial cells
same shape as medullary cells
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Generic distinction -comparati
ve post-fertilization events of
female reproductive system in establishment of
cystocarp nature of fusions - complexity of
male reproductive system
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Gracilaria intermedia cystocarps
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pericarp
carposporangia
inner gonimo- blast

medulla
cystocarp floor
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Gracilaria multinucleate tubular nutritive
cells to roof, to base
Gracilariopsis uninucleate conjunctor
cells at base
TAPPING BACK
Hydropuntia multinucleate tubular nutritive
cells at base of cystocarp
Gracilariophila (parasite)
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2
3
1
1
unfertilized female structure
-origin 3-cortical unit again -lower cell of
unit cell 1 supporting cell cutting off
carpogonial branch initial -cells 2 3
nutritive cells of carpogonial branch unit
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unfertilized 2-celled carpogonial branches
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-2-celled carpogonial branch on supporting
cell -straight trichogyne reaching thallus
surface -partly fusion of cortical nutritive
cells to carpogonium
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Partly fusion of neighboring cortical cells with
carpogonium vegetative nuclei remain in unfused
portion
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-diploid zygote nucleus in uninucleate
carpogonium -fused cortical cells nutritive
cells
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-young carpospore-bearing filaments
(gonimoblasts) cut off from carpogonial fusion
cell
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Generic character
How lower cells of young carpospore-bearing
filaments fuse back to multinucleate carpogonial
fusion cell
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young cystocarp Gracilariopsis
-very regular, progressive growth of
carpospore- bearing filaments
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Fusion of lower carposporophyte cells to
vegetative gametophytic cells
Gracilariopsis
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Gracilaria multinucleate tubular nutritive
cells to roof, to base
Gracilariopsis uninucleate conjunctor
cells at base
TAPPING BACK
Hydropuntia multinucleate tubular nutritive
cells at base of cystocarp
Gracilariophila (parasite)
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Gracilaria
Gracilariopsis
in shallow or deep pits
super- ficial
in deep pits, con- necting to vege- tative
cells
Hydropuntia
Gracilariophila
male structures
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Gurgel Fredericq 2004 rbcL phylogeny of the
Gracilariaceae, Bayesian Tree.
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Gurgel Fredericq 2004
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A meaningful global phylogeny of the
Gracilariaceae and the evolutionary patterns
found in it could only be obtained after
reaching a dataset composed of 35 taxa Before
that, taxa sampling played a major issue in
obtaining stable and meaningful phylogenies. So,
nowadays, when new taxa (i.e. distinct rbcL DNA
sequences) are added to the global phylogeny
they do not change the overall topology. Ready
for final taxonomic conclusions.
Gurgel Fredericq 2004 Bayesian Tree
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What has been established so far?
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Is high quality-agar (gel strength) correlated to
phylogeny? Is there character congruence
between agar gel strength (phenotype)
and molecular-based phylogenies (haplotype)? Can
sound phylogenies identify lineages characterized
by high-quality agar?
Gurgel Fredericq 2004
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G. vermiculophylla G. tenuistipitata G.
chilensis (90 agar worldwide, Zemke-White
Ohno 1999)
Proposed as a distinct genus by Gurgel
Fredericq 2004
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Agar Properties
Yield ( , dw/dw ) Gel Strength ( g. cm-2
) 3,6 Anhydro-galactose ( , dw/dw ) Gelling
Point ( C ) Boiling Point ( C )
Data in the Literature
1st Source of Variation (in the Agar Properties)
Strain / population Tissue / Thallus Age Light
Regime Temperature Life-cycle Reproductive status
? Methodologies (Whyte et al. 1984)
2nd Source of Variation
Extraction Standard vs. Alkali Strength
gel shape, Ø and crosshead speed
(plunger) 3,6 AG Resorcinol vs. IR
Spectrophotometer
Fred Gurgel, pers. comm
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Searching for Phylogenetic Patterns of Native Gel
StrengthsSampling for Published Data

• Obtain agar parameters for species for which we
  have phylogenetic data ( rbcL DNA sequences).
• Select methodologies that reflect the algaes
  most natural conditions.
• Extraction Standard (shredding ? boiling ?
  gelling ? freezing ? thawing ? washing)
• Strength method 1.5 gels, 1.0 cm Ø plungers
• Minimize Method Variation

Total number of Papers Surveyed 26 Total
number of Papers Selected 09
Fred Gurgel, pers. comm
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Gel Strength (g. cm-2)
Number of species with comparable agar data
G. chilensis Clade
Gracilaria s. s. Clade
Gracilariopsis Clade
Fred Gurgel, pers. comm
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Conclusions

• RbcL-based phylogenies reevaluated character
  evolution in the Gracilariaceae and inferred a
  new classification for Gracilaria sensu lato.
• The G. chilensis-clade and the genus Hydropuntia
  are reinforced as distinct taxa in the Gracilaria
  complex.
• Based on a literature review, data suggest that
  there is a strong correlation between phylogeny
  and agar gel strength (agar quality) between
  genera, and between average genetic divergence
  and gel strength values within each genus.

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ordinal family-level characters -based
on how unfertilized female system develops in
relation to vegetative growth cf. Kylin system
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Gracilaria multinucleate tubular nutritive
cells to roof
Gracilariopsis uninucleate
conjunctor cells
Hydropuntia multinucleate tubular nutritive
cells at base of cystocarp
Gracilariophila (parasite)
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Problem
differentiate among stages that are are
functional, versus abortive?? no auxiliary
cells!
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Gracilaria male structure development
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Gracilaria male structure development
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Gracilaria male structure development
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Gracilaria male structure development
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Gracilaria male structure development
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Gracilaria male structure development
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Gracilariopsis male structure development
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all genera
-tetrasporangial initials are surface cortical
cells -cruciate divisision of tetrasporangia
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Gracilariaceae from the vicinity of Bocas del Toro
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Gracilaria curtissiae
-thick thallus thinner lateral blade-like
proliferations
Photo A. Fricke O. Camacho-Hadad
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Photo A. Fricke O. Camacho-Hadad
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Gracilaria intermedia
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Gracilaria intermedia
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Photo A. Planas C. Fernández)
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Gracilaria cervicornis
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Photo M.C. Díaz Ruiz
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Photo R. Fikes
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Gracilaria domingensis
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Photo A. Fricke O. Camacho-Hadad
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Hydropuntia caudata
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Gracilaria galetensis
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Gracilaria hayi
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Gurgel Fredericq 2004