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

Gracilariaceae

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Photo: O.Camacho Hadad & Anna Fricke

HalymeniaceaeRhodymeniaceae

Gracilariaceae

vegetative structure: cellular medulla

family, ordinal level

Gracilaria

Hydropuntia

flat sp.

terete sp.mixed-sized cells

Gracilariaceae

Solieriaceae

Solieriaceae (Solieria)

loose filiform, or mixed cellular-filiform medulla

Halymeniaceae (Cryptonemia)

-cortical unit of 3 surface cells

1

1

2

2

3

Conjunctor cells fuse with neighboring cells, resulting in secondary pit connection formation

-inherently uniaxial

-uniaxial growth quickly disguised-axial cells: same shape as medullary cells

Generic distinction:

-comparative post-fertilization events of femalereproductive system in establishment of cystocarp: nature of fusions

- complexity of male reproductive system

Gracilaria intermedia cystocarps

pericarp

carposporangia

medullacystocarp floor

inner gonimo-blast

Gracilaria: multinucleate tubular nutritive cells to roof, to base

Gracilariopsis: uninucleate conjunctor cells at base

Gracilariophila(parasite)

Hydropuntia: multinucleatetubular nutritive cells at baseof cystocarp

“TAPPING BACK”

-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

1 1

2 3

unfertilized female structure

unfertilized 2-celled carpogonial branches

-2-celled carpogonial branch on supporting cell-straight trichogyne reaching thallus surface-partly fusion of cortical nutritive cells to carpogonium

Partly fusion of neighboring cortical cells with carpogonium; vegetative nuclei remain in unfused portion

-diploid zygote nucleus in uninucleate carpogonium;-fused cortical cells = nutritive cells

-young carpospore-bearing filaments (gonimoblasts) cut off from carpogonial fusion cell

How lower cells of young carpospore-bearing filaments fuse back to multinucleate carpogonial fusion cell

Generic character:

young cystocarp: Gracilariopsis

-very regular, progressive growth of carpospore- bearing filaments

Fusion of lower carposporophyte cells to vegetative gametophytic cells Gracilariopsis

Gracilaria: multinucleate tubular nutritive cells to roof, to base

Gracilariopsis: uninucleate conjunctor cells at base

Gracilariophila(parasite)

Hydropuntia: multinucleatetubular nutritive cells at baseof cystocarp

“TAPPING BACK”

Gracilaria: Gracilariopsis:

Gracilariophila: Hydropuntia:

male structures

in shallow or deep pits

super-ficial

in deep pits, con-necting to vege-tative cells

Gurgel & Fredericq 2004 = rbcL phylogeny of the Gracilariaceae, Bayesian Tree.

Global Phylogeny of the GracilariaceaeBayesian Inferred Phylogeny

Gurgel & Fredericq 2004

Gurgel & Fredericq 2004Bayesian Tree

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.

What has been established so far?

G. tenuistipitataG. tenuistipitataG. tenuistipitataG. tenuistipitataG. tenuistipitataG. chilensisG. chilensisG. vermiculophyllaG. vermiculophylla

94

97

85

Gp. hommersandii (outgroup)

H. urvillei

H. aff. changiiH. aff. changiiH. changiiH. crassissimaH. corneaH. caudataH. secundataH. perplexaH. preissianaH. edulisH. rangiferinaH. millardetiiH. eucheumatoides

82 9989

G. beckeri83

G. acuelata

G. textoriiG. ornataG. bursa-pastorisG. cervicornisG. tikvahiaeG. mammillarisG. canaliculataG. salicorniaG. gracilisG. pacifica

979167

75

Hydropuntia

Gracilaria

‘New Genus’

Genera:

Chilensis-typespermatangia

‘Verrucosa’-typespermatangia

Roundedcarposporophyte

Lobedcarposporophyte

Textorii-typespermatangia

Verrucosa-typespermatangia

Sub-Genera:

Is high quality-agar (gel strength)correlated to phylogeny?

Is there character congruence between agar gel strength (phenotype) andmolecular-based phylogenies (haplotype)?

Can sound phylogenies identifylineages characterized by high-qualityagar?

Gurgel & Fredericq 2004

G. tenuistipitata JAPANG. tenuistipitata VA, USA

G. chilensis CHILE

74 100

G. beckeri SOUTH AFRICAG. capensis SOUTH AFRICA

G. viellardii TAIWANG. spinulosa TAIWAN

G. sp . PHILIPPINESG. flabelliformis VENEZUELA

G.occidentali s LA, USAG. ornata PANAMA

G. textorii JAPANG. multipartita FRANCE

G. bursa-pastori s ITALY

G. cuneata FL, USAG. cuneata PANAMA

G. sp. PANAMAG. sp. VENEZUELA

G. sp. PANAMAG. mammillaris LA, USAG. sp. BRAZILG. intermedia VENEZUELA

G. venezuelensis FL, USAG. canaliculata PHILIPPINES

G. salicornia PHILIPPINESG. arcuata PHILIPPINESG. gracilis ENGLANDG. gracilis FRANCE

G. pacifica WA, USA

G. edulis PHILIPPINESG. preissiana AUSTRALIA

G. dentata GHANAG. dentata PHILIPPINES

G. eucheumatoides PHILIPPINESG. urvillei i AUSTRALIA

9997

94

69

5254

G. apiculata VENEZUELAG. domingensi s BRAZIL

G. cervicornis FL, USAG. curtissae VENEZUELA

898897

798596

98

7392

9599

100100

100100

100

100

G. usneoide s MEXICO98G. cornea VENEZUELAG. crassissima PANAMA

G. caudata FL, USAG. secunda FL, USA

100 100100

100

100

100

G. tikvahiae CANADAG. lacinulat a VENEZUELAG. damaecornis FL, USA

98100

G. vermiculophyllaG. tenuistipitataG. chilensis

(90% agar worldwide,Zemke-White & Ohno 1999)

Proposed as a distinct genusby Gurgel & Fredericq 2004

Agar Properties: Yield ( %, dw/dw )Gel Strength ( g. cm-2 )3,6 Anhydro-galactose ( %, dw/dw )Gelling Point ( °C )Boiling Point ( °C )

1st Source of Variation:(in the Agar Properties)

Strain / population‘Tissue’ / Thallus AgeLight RegimeTemperatureLife-cycleReproductive 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

Data in the Literature:

Fred Gurgel, pers. comm

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 algae’s 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 = 26Total number of Papers Selected = 09

Fred Gurgel, pers. comm

1 2 3 4 5 6 7 8 9 10 11

0

200

400

600

800

G. chilensisClade

GelStrength(g. cm-2)

Number of species with comparable agar data

Gracilaria s. s.Gracilaria s. s.CladeClade

GracilariopsisClade

Fred Gurgel, pers. comm

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.

ordinal & family-level characters:

-based on how unfertilized female system develops in relation to vegetative growth

cf. Kylin system

Gracilaria: multinucleate tubular nutritive cells to roof

Gracilariopsis: uninucleate conjunctor cells

Gracilariophila(parasite)

Hydropuntia: multinucleate tubular nutritive cells at baseof cystocarp

Problem:

*differentiate among stages that are are functional, versus abortive??

*no auxiliary cells!

Gracilaria: male structure development

Gracilaria: male structure development

Gracilaria: male structure development

Gracilaria: male structure development

Gracilaria: male structure development

Gracilaria: male structure development

Gracilariopsis: male structure development

-tetrasporangial initials are surface cortical cells-cruciate divisision of tetrasporangia

all genera:

Gracilariaceae from the vicinity of Bocas del Toro

Gracilaria curtissiae-thick thallus; thinner lateral blade-like proliferations

Photo: A. Fricke & O. Camacho-Hadad

Photo: A. Fricke & O. Camacho-Hadad

Gracilaria intermedia

Gracilaria intermedia

Photo: A. Planas & C. Fernández)

Gracilaria cervicornis

Photo: M.C. Díaz Ruiz

Photo: R. Fikes

Gracilaria domingensis

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Photo: A. Fricke & O. Camacho-Hadad

Hydropuntia caudata

Gracilaria galetensis

Gracilaria hayi

Global Phylogeny of the GracilariaceaeBayesian Inferred Phylogeny

GTR+inv+gama100,00 generations, 4 chains

Burn in = 20,000

Gurgel & Fredericq 2004