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

1. Lecture 2: Common red algal families in the vicinity of Bocas del Toro:Gracilariaceae Photo: O.Camacho Hadad & Anna Fricke

2. Gracilariaceae Rhodymeniaceae Halymeniaceae

3. family, ordinal level flat sp. vegetative structure: cellular medulla Gracilaria terete sp. Hydropuntia mixed-sized cells

4. Solieriaceae Gracilariaceae

5. Solieriaceae (Solieria) loose filiform, or mixed cellular-filiform medulla

6. Halymeniaceae (Cryptonemia)

7. 2 1 2 3 1 -cortical unit of 3 surface cells

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

9. -inherently uniaxial

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

11. Generic distinction: -comparative post-fertilization events of female reproductive system in establishment of cystocarp: nature of fusions - complexity of male reproductive system

12. Gracilaria intermedia cystocarps

13. pericarp carposporangia inner gonimo- blast medulla cystocarp floor

14. 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)

15. 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

16. unfertilized 2-celled carpogonial branches

17. -2-celled carpogonial branch on supporting cell -straight trichogyne reaching thallus surface -partly fusion of cortical nutritive cells to carpogonium

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

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

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

21. Generic character: How lower cells of young carpospore-bearing filaments fuse back to multinucleate carpogonial fusion cell

22. young cystocarp: Gracilariopsis -very regular, progressive growth of carpospore- bearing filaments

23. Fusion of lower carposporophyte cells to vegetative gametophytic cells Gracilariopsis

24. 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)

25. Gracilaria: Gracilariopsis: in shallow or deep pits super- ficial in deep pits, con- necting to vege- tative cells Hydropuntia: Gracilariophila: male structures

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

27. Global Phylogeny of the Gracilariaceae Bayesian Inferred Phylogeny Gurgel & Fredericq 2004

28. 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

29. Sub-Genera: Genera: G. beckeri 83 G. textorii 67 91 G. ornata 97 Textorii-type spermatangia G. bursa-pastoris G. cervicornis Gracilaria G. tikvahiae G. mammillaris G. canaliculata Verrucosa-type spermatangia G. salicornia 75 G. gracilis G. pacifica G. acuelata H. aff. changii H. aff. changii H. changii Rounded carposporophyte 97 H. crassissima H. cornea H. caudata Hydropuntia H. secundata H. perplexa 89 82 99 H. preissiana H. edulis Lobed carposporophyte H. rangiferina 94 H. millardetii H. eucheumatoides H. urvillei G. tenuistipitata G. tenuistipitata Chilensis-type spermatangia G. tenuistipitata G. tenuistipitata ‘New Genus’ G. tenuistipitata 85 G. chilensis G. chilensis ‘Verrucosa’-type spermatangia G. vermiculophylla G. vermiculophylla Gp. hommersandii (outgroup) What has been established so far?

30. 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

31. G. vermiculophylla G. tenuistipitata G. chilensis (90% agar worldwide, Zemke-White & Ohno 1999) Proposed as a distinct genus by Gurgel & Fredericq 2004

32. 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 2nd Source of Variation: ≠ Methodologies (Whyte et al. 1984): * Extraction: Standard vs. Alkali * Strength: gel shape, Ø and crosshead speed (plunger) * 3,6 AG: Resorcinol vs. IR Spectrophotometer Fred Gurgel, pers. comm

33. Searching for Phylogenetic Patterns of Native Gel StrengthsSampling for Published Data: • Obtainagar 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 = 26 Total number of Papers Selected = 09 Fred Gurgel, pers. comm

34. Gel Strength (g. cm-2) Number of species with comparable agar data G. chilensis Clade Gracilariopsis Clade Gracilaria s. s. Clade Fred Gurgel, pers. comm

35. Conclusions • RbcL-based phylogenies reevaluated character evolution in the Gracilariaceae and inferred a new classification for Gracilariasensu 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.

36. ordinal & family-level characters: -based on how unfertilized female system develops in relation to vegetative growth cf. Kylin system

37. Gracilaria:multinucleate tubular nutritive cells to roof Gracilariopsis: uninucleate conjunctor cells Hydropuntia:multinucleate tubular nutritive cells at base of cystocarp Gracilariophila (parasite)

38. Problem: *differentiate among stages that are are functional, versus abortive?? *no auxiliary cells!

39. Gracilaria: male structure development

40. Gracilaria: male structure development

41. Gracilaria: male structure development

42. Gracilaria: male structure development

43. Gracilaria: male structure development

44. Gracilaria: male structure development

45. Gracilariopsis:male structure development

46. all genera: -tetrasporangial initials are surface cortical cells -cruciate divisision of tetrasporangia

47. Gracilariaceae from the vicinity of Bocas del Toro

48. Gracilaria curtissiae -thick thallus; thinner lateral blade-like proliferations Photo: A. Fricke & O. Camacho-Hadad

49. Photo: A. Fricke & O. Camacho-Hadad

50. Gracilaria intermedia