Marine Animals I. The Invertebrates OCN 201 Biology Lecture 6 Illustration : Ernst Haeckel Arthropods Segmented Worms The Animal Vertebrates Family Tree Mollusks Echinoderms Round Worms Cnidarians Bilateria Ctenophores Radiata Flatworms PlacozoaNo symmetry Sponges Ancestral Protist 1336 The Animal Animal The Family Tree Family (Science, Dec 2013) Dec (Science, ctenophores *Corresponding author. E-mail: [email protected] E-mail: author. *Corresponding The list of author affi liations is available in the full article online. article full the in available is liations affi author of list The all animal species, including our own. our including species, animal all shed light not only on the biology of these extant organisms but also on the evolutionary history of of history evolutionary the on also but organisms extant these of biology the on only not light shed this study, will yield myriad discoveries about our most distant animal relatives, many of which will will which of many relatives, animal distant most our about discoveries myriad yield will study, this evolutionary framework, along with the comprehensive genomic resources made available through through available made resources genomic comprehensive the with along framework, evolutionary for major losses and/or gains of sophisticated cell types, including nerve and muscle cells. This These results present a newly supported view of early animal evolution that accounts accounts that evolution animal early of view supported newly a present results These Discussion: therefore, may have independently evolved these cell types. cell these evolved independently have may therefore, mesodermal cells, they lack many of the genes involved in bilaterian mesodermal specifi cation and, and, cation specifi mesodermal bilaterian in involved genes the of many lack they cells, mesodermal We also fi nd that, although although that, nd fi also We necessary genetic machinery for a functioning nervous system but may have lost these cell types. types. cell these lost have may but system nervous for a functioning machinery genetic necessary and the sponge the sponge and extant animals. We fi nd that the sets of neural components present in the genomes of of genomes the in present components neural of sets the that nd fi We animals. extant Our phylogenetic analyses suggest that ctenophores are the sister group to the rest of the the of rest the to group sister the are ctenophores that suggest analyses phylogenetic Our Results: dermal cell types, among others. among types, cell dermal inventories on signaling pathway components and genes known to be critical to neural and meso- and neural to critical be to known genes and components pathway signaling on inventories using both sequence matrices and information on gene content. We conducted extensive genomic genomic extensive conducted We content. gene on information and matrices sequence both using phore phore We have sequenced, annotated, and analyzed the 150-megabase genome of the cteno- the of genome 150-megabase the analyzed and annotated, sequenced, have We Methods: of ctenophores affects how we think about the early evolution of these cell types. cell these of evolution early the about think we how affects ctenophores of complex cell types with bilaterians (such as neural and mesodermal cells), the phylogenetic position position phylogenetic the cells), mesodermal and neural as (such bilaterians with types cell complex Ctenophora as the earliest diverging animal lineage. Because ctenophores share some of the same same the of some share ctenophores Because lineage. animal diverging earliest the as Ctenophora era (sponges) was the earliest diverging animal lineage, but recent reports have instead suggested suggested instead have reports recent but lineage, animal diverging earliest the was (sponges) era other animals has been a source of long-standing debate. Until recently, it was thought that Porif- that thought was it recently, Until debate. long-standing of source a been has animals other occurred early in animal evolution. The phylogenetic relationship of ctenophores (comb jellies) to to jellies) (comb ctenophores of relationship phylogenetic The evolution. animal in early occurred Introduction: A Mark Q. Martindale, Andreas D. Baxevanis* D. Andreas Martindale, Q. Mark Steven H. D. Haddock, Casey W. Dunn, Tyra G. Wolfsberg, James C. Mullikin, Mullikin, C. James Wolfsberg, G. Tyra Dunn, W. Casey Haddock, D. H. Steven NISC Comparative Sequencing Program, Stephen A. Smith, Nicholas H. Putnam, Putnam, H. Nicholas Smith, A. Stephen Program, Sequencing Comparative NISC David K. Simmons, Bernard J. Koch, Warren R. Francis, Paul Havlak, Havlak, Paul Francis, R. Warren Koch, J. Bernard Simmons, K. David Joseph F. Ryan, Kevin Pang, Christine E. Schnitzler, Anh-Dao Nguyen, R. Travis Moreland, Moreland, Travis R. Nguyen, Anh-Dao Schnitzler, E. Christine Pang, Kevin Ryan, F. Joseph for Cell Type Evolution Type Cell for and Its Implications Implications Its and leidyi Mnemiopsis RESEARCH ARTICLE Ctenophore the of Genome The RESEARCH ARTICLE ARTICLE RESEARCH . We . We have leidyi performed Mnemiopsis detailed phylogenetic analyses on these new data An understanding of ctenophore biology is critical for reconstructing events that are quite similar, suggesting that are quite sponges have similar, the queenslandica Amphimedon has most of the genes coding for structural components of of components structural for coding genes the of most has Mnemiopsis 13 DECEMBER 2013 VOL 342 342 VOL 2013 DECEMBER 13 RESEARCH ARTICLE B Ctenophores Echinoderms SUMMARY Cnidarians P u b l i s h Sponges e d www.sciencemag.org www.sciencemag.org SCIENCE RESEARCH ARTICLE b 1242592-4 y replicates. acid characters. Circles on nodes indicate 100% bootstrap support. Support Fig. 3. analysis of Tree by produced the maximum-likelihood EST Set. A A Choanoflagellata Ctenophora A Porifera Placozoa Vertebrates Bilateria Cnidaria S Vertebrates = 100 bootstrap 100 = Mnemiopsis Text Fig. 1. M. leidyi life history and anatomy. (A)AdultM. leidyi (about 10 cm Later development of M. leidyi embryo shown oral side down. Embryos are about 72 long). ( B)Close-upviewofcombrows.(C)Aboralviewofcydippidstage.(D)One- 200 mm. See the supplementary materials fo ram o r ed e t a i l e dd e s c r i p t i o no ft h e celled fertilized embryo. ( E to H)E a r l yc l e a v a g es tI a)Gastrulastage.( g e s .( J to M) ctenophore body plan. [Photo credit for (A): courtesy of Bruno Vellutini] support 0.2 Radiata Phylogenetic Position of M. leidyi ABBi Bi CBi D E F Bi Bi Bi The availability of the complete genome of Cn Ct Cn Cn Cn Cn M. leidyi evolved independently in these two lineages. two these in independently evolved ently than in bilaterians, suggesting that they perhaps perhaps they that suggesting bilaterians, in than ently ctenophore mesodermal cell types are specifi ed differ- ed specifi are types cell mesodermal ctenophore many of many in these factors underlined. Absent components are in red. The lack of of lack The red. in are components Absent underlined. Mnemiopsis Mnemiopsis genes genes in fl fl a g e l l a t a . ( Arthropods has allowed us to improve on the ctenophore Choano- outgroup the and of animals branches main ) Summary of the relationships of the fi ve ve fi the of relationships the of Summary ) B ( . leidyi M. the the origin of cell types. mesodermal and its implications regarding regarding implications its and leidyi Mnemiopsis Ct Cn Tr Tr Ct Ct The phylogenetic position of the ctenophore References Tables S1 to S31 to S1 Tables Figs. S1 to S10 to S1 Figs. Materials and Methods and Materials SUPPLEMENTARY MATERIALS SUPPLEMENTARY in in Fig. 6. Inventory of myogenic components components myogenic of Inventory 6. Fig. Fig. 5. The origin of postsynaptic genes. postsynaptic of origin The 5. Fig. analysis of gene content. gene of analysis Fig. 4. Tree produced by maximum-likelihood maximum-likelihood by produced Tree 4. Fig. analysis of the EST set. EST the of analysis Fig. 3. Tree produced by maximum-likelihood maximum-likelihood by produced Tree 3. Fig. C of the fi ve deep clades of animals. of clades deep ve fi the of Fig. 2. Previously proposed relationships relationships proposed Previously 2. Fig. Tr sampling used in previous phylogenomic analyses Bilateria Tr 1. Fig. Ct Po Po Po ARTICLE FULL THE IN FIGURES Po Po Po Ct Tr Tr of gene sequence evolution. We assessed two data Wnt/Wg . leidyi M. Arthropods http://dx.doi.org/10.1126/science.1242592 READ THE FULL ARTICLE ONLINE ARTICLE FULL THE READ (Cn,Ct) (Ct,Bi) (Po,) (Ct,) matrices that differ in breadth of taxon sampling 96 (Tr,) (Bi,) 13 DECEMBER 2013 VOL 342 Shh/hh and fraction of missing data: a “Genome Set ” that 82 Fig. 2. Previously proposed relationships of the five deep clades of animals. The label at the includes only data from complete genomes (13 ani- Fig. 1. M. leidyi life history and anatomy. (A)Adult 77 bottom of each pane corresponds to the header of Table 1. ( A)C o e l e n t e r a t ah y p oB t)Ctenophoraas h e s i s .( mals, 19.6% missing data) and an “EST Set ” that M. leidyi (about 10 cm Later development of M. leidyi embryo shown oral side down. Embryos are about Ancestral Ancestral life history and anatomy. and history life leidyi M. Components present in the sister to Bilateria. ( C)P o r i f e r aa ss i s t e rg r o u pt ot h er e s toD)Ctenophoraassistergrouptothe fM e t a z o a .( includes partial genomic data from many taxa (58 Mnemiopsis DOI: 10.1126/science.1242592 DOI: Science Cite this article as J. F. Ryan Ryan F. J. as article this Cite Placozoa 98 rest of Metazoa. ( E)PlacozoaassistergrouptotherestofMetazoa.( long).