Se ha denunciado esta presentación.
Utilizamos tu perfil de LinkedIn y tus datos de actividad para personalizar los anuncios y mostrarte publicidad más relevante. Puedes cambiar tus preferencias de publicidad en cualquier momento.

BIS2C: Lecture 32 - Deuterosomes II: Chordates

736 visualizaciones

Publicado el

BIS2C: Lecture 32 - Deuterosomes II: Chordates

Publicado en: Ciencias
  • Sé el primero en comentar

BIS2C: Lecture 32 - Deuterosomes II: Chordates

  1. 1. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Lecture 32: Deuterosomes II: Chordates BIS 002C Biodiversity & the Tree of Life Spring 2016 Prof. Jonathan Eisen 2
  2. 2. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Where we are going and where we have been… 3 •Previous lecture: •31: Deuterosomes I: Echinoderms & Hemichordates •Current Lecture: •32: Deuterosomes II: Chordates •Next Lecture: •33: Deuterosomes III: Chordates II
  3. 3. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Animal Diversity 4 Diploblasts Triploblasts Monoblasts
  4. 4. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Triploblasts 5 Triploblasts
  5. 5. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Protostomes 6
  6. 6. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Clicker What evidence is consistent with echinoderms being deuterostomes? A. Molecular phylogenetics B. Blastopore developing into anus C. Presence of bilateral symmetry D. All of A-C E. None of A-C 7
  7. 7. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Clicker What evidence is consistent with echinoderms being deuterostomes? A. Molecular phylogenetics B. Blastopore developing into anus C. Presence of bilateral symmetry D. All of A-C E. None of A-C 8
  8. 8. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Chordates 9 Echinoderms Hemichordates Chordates
  9. 9. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Chordates 10 Chordates Common ancestor (bilaterally symmetrical, pharyngeal slits present) Echinoderms Hemichordates Lancelets Tunicates VertebratesVertebral column, anterior skull, large brain, ventral heart Notochord, dorsal hollow nerve cord, post-anal tail Radial symmetry as adults, calcified internal plates, loss of pharyngeal slits Ciliated larvae Ambulacrarians Focus on Chordates
  10. 10. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Deuterostomes 11
  11. 11. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Deuterostomes 11
  12. 12. Chordate Derived Traits Most Apparent in Juveniles !12Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  13. 13. Notochord !13Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 • Notochord is a dorsal supporting rod. • Core of large cells with fluid-filled vacuoles, making it rigid but flexible. • In tunicates it is lost during metamorphosis to the adult stage. • In vertebrates it is replaced by skeletal structures.
  14. 14. Dorsal hollow nerve cord !14Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 • Formed by an embryonic folding of the ectoderm • Develops to form the central nervous system in vertebrates
  15. 15. Post Anal Tail !15Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 • Extension of the body past the anal opening • In some species (e.g., humans) most visible in embryos • The combination of postanal tail, notochord, and muscles provides propulsion
  16. 16. Pharyngeal Slits !16Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 • The pharynx is a muscular organ that brings water in through the mouth (via cilia) which then passes through a series of openings to the outside (slits). • Ancestral pharyngeal slits present at some developmental stage; often lost or modified in adults. • Supported by pharyngeal arches.
  17. 17. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Clicker 17 Why are pharyngeal slits NOT considered a synapomorphy (shared derived trait) of chordates? A. They occur in other deuterostomes B. They are lost in some chordates C. They are modified into gills in vertebrates D. They only occur in the embryo of some chordates
  18. 18. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Clicker 18 Why are pharyngeal slits NOT considered a synapomorphy (shared derived trait) of chordates? A. They occur in other deuterostomes B. They are lost in some chordates C. They are modified into gills in vertebrates D. They only occur in the embryo of some chordates
  19. 19. Figure 33.1 Phylogeny of the Deuterostomes !19Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  20. 20. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Chordates 20 Chordates Common ancestor (bilaterally symmetrical, pharyngeal slits present) Echinoderms Hemichordates Lancelets Tunicates VertebratesVertebral column, anterior skull, large brain, ventral heart Notochord, dorsal hollow nerve cord, post-anal tail Radial symmetry as adults, calcified internal plates, loss of pharyngeal slits Ciliated larvae Ambulacrarians Focus on Chordates
  21. 21. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Chordates 21 Chordates Common ancestor (bilaterally symmetrical, pharyngeal slits present) Echinoderms Hemichordates Lancelets Tunicates VertebratesVertebral column, anterior skull, large brain, ventral heart Notochord, dorsal hollow nerve cord, post-anal tail Radial symmetry as adults, calcified internal plates, loss of pharyngeal slits Ciliated larvae Ambulacrarians Three Major Groups *Lancelets *Tunicates *Vertebrates
  22. 22. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Lancelets (aka Cephalochordates) 22 Chordates Common ancestor (bilaterally symmetrical, pharyngeal slits present) Echinoderms Hemichordates Lancelets Tunicates VertebratesVertebral column, anterior skull, large brain, ventral heart Notochord, dorsal hollow nerve cord, post-anal tail Radial symmetry as adults, calcified internal plates, loss of pharyngeal slits Ciliated larvae Ambulacrarians Focus on Lancelets
  23. 23. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Lancelet development 23
  24. 24. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 24 Branchiostoma lanceolatum Gut TailAnus Dorsal hollow nerve cord NotochordPharyngeal slits Lancelet Has Key Chordate Features
  25. 25. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 25 Branchiostoma lanceolatum TailAnus Dorsal hollow nerve cord NotochordPharyngeal slits Lancelet Features • Lancelets (aka amphioxus) are very small, less than 5 cm. • Notochord is retained throughout life. • Burrow in sand with head protruding; also swim. • Pharynx is enlarged to form a pharyngeal basket for filtering prey from the water. • Fertilization takes place in the water. • Segmented body muscles
  26. 26. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Tunicates 26 Chordates Common ancestor (bilaterally symmetrical, pharyngeal slits present) Echinoderms Hemichordates Lancelets Tunicates VertebratesVertebral column, anterior skull, large brain, ventral heart Notochord, dorsal hollow nerve cord, post-anal tail Radial symmetry as adults, calcified internal plates, loss of pharyngeal slits Ciliated larvae Ambulacrarians Focus on Tunicates
  27. 27. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Adult Tunicates 27 • Tunicates (sea squirts or ascidians, thaliaceans, and larvaceans): • Sea squirts form colonies by budding from a single founder. Colonies may be meters across. • Adult body is baglike and enclosed in a “tunic” of proteins and complex polysaccharides secreted by the epidermis.
  28. 28. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Adult Tunicates 28 • Solitary tunicates seem to lack all of the synapomorphies of chordates? • No dorsal hollow nerve cord, no notochord, no postanal tail
  29. 29. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Adult Tunicates 29 • Solitary tunicates seem to lack all of the synapomorphies of chordates? • No dorsal hollow nerve cord, no notochord, no postanal tail HOW ARE THESE CHORDATES?
  30. 30. Photo 44.18 Developing oocytes of sea squirt (ascidian; chordate) Ciona intestinalis. LM. !30Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  31. 31. Photo 44.19 Sea squirt (primitive chordate, C. intestinalis): free-swimming larva. !31Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  32. 32. Photo 44.20 C. intestinalis: early settled larva on substrate. !32Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  33. 33. Photo 44.21 C. intestinalis: further metamorphosis of early settled larva. !33Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  34. 34. Photo 44.22 C. intestinalis: 36 hours after settlement of larva. !34Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  35. 35. Photo 44.23 C. intestinalis: 4 days after settlement of larva. Features of adult can be seen. !35Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  36. 36. Photo 44.24 C. intestinalis: 7 days after settlement of larva !36Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  37. 37. Photo 44.25 Sea squirt juvenile C. intestinalis. Siphons and other adult features evident. !37Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  38. 38. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Juvenile Tunicates 38 Ascidian tunicate larva • Sea squirt larvae have pharyngeal slits, a hollow nerve cord, and notochord in the tail region. • The swimming, tadpolelike larvae suggest a relationship between tunicates and vertebrates. • Larvacean tunicates do not undergo the metamorphosis and retain all of the chordate features. Larvacean tunicates
  39. 39. • Where have we seen big differences between larval forms and adult forms? !39Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  40. 40. Symmetry Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  41. 41. Symmetry Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Larvae are bilateral
  42. 42. Tunicate Diversity !41Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 • ~2,000 described species, all marine filter-feeders • Body surrounded by a tunic; a thick cellulose covering • Mostly sessile, one lineage free-swimming • Feeding through incurrent and excurrent siphons Solitary Colonial Free-swimming
  43. 43. !42Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  44. 44. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Tunicate colony Lissoclinum patellum 43
  45. 45. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 1982 44 http://pubs.acs.org/doi/abs/10.1021/jo00349a002
  46. 46. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 45 http://pubs.acs.org/doi/pdf/10.1021/jm00126a034
  47. 47. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Lissoclinum & relatives have cyanobacteria symbionts 46 Figure 2.Photosymbiotic ascidians with tunic spicules. Colonies in situ and tunic spicules (inset) of Didemnum molle (A), Trididemnum miniatum (B), Lissoclinum patella (C), Lissoclinum punctatum (D), and Lissoclinum timorense (E). Tunic cells contain Prochloron cells in the tunic of Lissoclinum punctatum (F). Scale bars = 20 µm. 
  48. 48. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Lesson … • If you find a novel biochemical activity in some animal … • Most likely it is NOT actually from the animal 48
  49. 49. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Clicker What groups of animals have we seen to have autotrophic mutualistic symbionts? A. Annelids B. Cnidarians C. Protostomes D. Chordates E. All of the above 49
  50. 50. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Clicker What groups of animals have we seen to have autotrophic mutualistic symbionts? A. Annelids B. Cnidarians C. Protostomes D. Chordates E. All of the above 50
  51. 51. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Clicker What groups of animals have we seen to have autotrophic mutualistic symbionts? A. Annelids (Tubeworms) B. Cnidarians (Coral) C. Protostomes (Tubeworms) D. Chordates (Tunicates) E. All of the above 51
  52. 52. Filled with Bacteria 52Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Basic Tubeworm Anatomy Dr. Colleen Cavanaugh used microscopy techniques in 1981 and discovered billions of bacterial cells packed inside the tubeworm’s trophosome. 1011 bacteria per gram of trophosome!! Plume Trophosome
  53. 53. Coral Symbiosis with Dinoflagellates !53Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Corals contain symbiotic dinoflagellates (algae) called zooxanthellae
  54. 54. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Other Examples? 54
  55. 55. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Other Types of Mutualisms in Animals? 55
  56. 56. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Filarial Nematodes Permanently House Wolbachia 56
  57. 57. Vertebrate Origins !57Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Ciliated larvae AmbulacrariansChordates Common ancestor (bilaterally symmetrical, pharyngeal slits present) Echinoderms Hemichordates Lancelets Tunicates Vertebrates Radial symmetry as adults, calcified internal plates, loss of pharyngeal slits Vertebral column, anterior skull, large brain, ventral heart Notochord, dorsal hollow nerve cord, post-anal tail
  58. 58. The Vertebrate Body Plan (not in all …) !58Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Anterior skull enclosing a large brain A jointed, dorsal vertebral column replaces the notochord during early development. Internal Organs suspended in a coelom Well-developed circulatory system driven by a ventral heart Rigid Internal Skeleton
  59. 59. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Vertebrate Evolution • The structural features can support large, active animals. • Internal skeleton supports an extensive muscular system that gets oxygen from the circulatory system and is controlled by the nervous system. • These features allowed vertebrates to diversify widely. 59
  60. 60. Phylogeny of the Living Vertebrates !60Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016
  61. 61. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Vertebrates and Land • All other deuterostomes are marine. • Vertebrates probably evolved in the oceans or estuarine environments during the Cambrian period. • They have radiated into marine, freshwater, terrestrial, and aerial environments. 61
  62. 62. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Jawless Fishes (hagfish and lampreys) 62
  63. 63. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Sister group for all other vertebrates 63 Hagfish
  64. 64. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 • Weak circulatory system w/ 3 small hearts, a partial cranium, no stomach, no jaws • NO BONE (skeleton is cartilage); no vertebrae. • Blind and produce large amounts of slime as a defense • They have a specialized structure to capture prey and tear up dead organisms. • Development is direct; adults can change sex from year to year. 64 Hagfish not quite full vertebrates
  65. 65. Photo 33.18 Pacific hagfish (Eptatretus stouti).
  66. 66. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 • https://youtu.be/bqk0mnMgwUQ 66
  67. 67. You’ve Been Slimed
  68. 68. !69Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Anterior skull enclosing a large brain A jointed, dorsal vertebral column replaces the notochord during early development. Internal Organs suspended in a coelom Rigid Internal Skeleton Well-developed circulatory system driven by a ventral heart The Vertebrate Body Plan
  69. 69. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 70 Lampreys
  70. 70. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 Lampreys 71 • Complete cranium and cartilaginous vertebrae. • Complete metamorphosis from filter-feeding larvae (ammocoetes), which are similar to lancelets. • No bone, no jaws, but cartilaginous vertebrae are present • Sucker- like mouth with rasping teeth • Many species are ectoparasites of fish
  71. 71. Photo 33.17 Anadromous lamprey (Petromyzon marinus); Rhode Island.
  72. 72. Slides by Jonathan Eisen for BIS2C at UC Davis Spring 2016 73

×