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Metamorphosis: A multi-kingdom approach

Andreas Heyland, Jason Hodin, Cory Bishop, and Leonid Moroz

This symposium is sponsored by the Whitney Laboratory for Marine Bioscience, the University of Florida, SICB and the American Microscopic Society


NEW! Open access table of contents, with free PDFs of all symposium papers

Press Release (.pdf)

Symposium questionnaire and discussion thread on SICB bulletin board

Symposium schedule

Contributed talks and posters associated with the symposium



The study of life history evolution in general and metamorphosis in particular embodies disparate approaches, theory, methodology and taxonomic choice. With this symposium, we aim to create a platform of presentation and discussion that is conducive to forging a unification of this topic, and in due course, to create new directions of inquiry. Specifically, this symposium will integrate ecological, developmental, physiological and evolutionary perspectives on metamorphosis and analyze the signaling architecture of this life history transition across kingdoms.

Although the term metamorphosis generally invokes life history transitions in animal phyla, we propose to broaden the concept to include comparable life history transitions in fungi and multicellular algae, and we have invited key researchers working on these groups in order to gain their perspective. This broad taxonomic approach will allow identification of instances of co-option and parallel evolution of traits related to a metamorphic life history, thus expanding our knowledge of how natural selection acts on life history strategies in general.

Research on model organisms provides the bulk of the data for comparisons of developmental signaling pathways among distantly related organisms, but necessarily fails to be informative about evolutionary causation, primarily due to limited taxonomic sampling within widely divergent taxa (for review see 1). The apparent consequence has been a systematic bias in the interpretation of developmental character evolution toward homology. The need for a strict comparative methodology will only increase as model systems inexorably generate new data on developmental signaling pathways. Thus, in order to provide a broader context in which to interpret shared ontogenetic patterns, and in particular to assess the frequency of homoplasy in the evolution of development, it is necessary to consult a wider variety of organisms, and importantly, their attendant life history traits. In this context, evolutionary comparisons within more restricted taxonomic groupings are indispensable for uncovering the mechanistic underpinnings of evolutionary change.

The evolutionary patterns and consequences of gain and loss of metamorphosis in chordates, arthropods and a variety of marine invertebrates has been the subject of much debate (e.g. 2-5). Because such radical alterations in organsimal life histories correlate with profound changes in developmental patterns, an understanding of the overall mechanics of life history evolution will inform ongoing interpretations of evolution of ontogenetic mechanisms. Furthermore, the fact that the evolutionary loss of a metamorphic life history has been hypothesized to have occurred repeatedly within numerous animal phyla underscores the importance of a comparative approach to understanding the evolution of metamorphosis. That EvoDevo researchers are increasingly recognizing the power of such comparative approaches makes this symposium all the more timely.

Organization of symposium

The symposium "Metamorphosis: A multi-kingdom approach" is a society-wide symposium including one discussion periods as well as a contributed paper (talk) and poster session. We ask all participants (both presenters and non-presenters) to provide a provisional definition of metamorphosis (see questionnaire), and this will form part of the basis for one of our discussions. We encourage speakers to bring students and post-docs from their labs to present additional material in form of posters. This will give more room for informal discussion outside the rather compressed time-line of the symposium (30 minute talks for each speaker plus one 30 minute discussion period).








Andreas Heyland

University of Florida,Whitney Laboratory, St. Augustine, FL (USA)


Metamorphosis: is it under stimulatory or inhibitory control?

Cory Bishop, Jan Pechenik and Mike Hadfield

Kewalo Marine Laboratory, University of Hawai'i ,Honolulu, HI (USA) and Tufts University, Boston, MA (USA)


The origin of the metazoan biphasic life cycle: new insights from an ancient phylum

Sandie Degnan and Bernie Degnan

University of Queensland (AUSTRALIA)


Nitric oxide represses Arabidopsis flowering

Zhen-Ming Pei

Duke University, Durham, NC (USA)


Sclerotial morphogenesis in fungi is induced by oxidative stress

Christos Georgiou
University of Patras (GREECE)


Coffee Break


Applying the concept of metamorphosis to the crustose-to-erect thallus transition of macroalgae

Bernabé Santelices and J.L. Alvorado
Facultad de Ciencias Biológicas
Pontificia Universidad Católica (CHILE)


Expanding Networks: A hypothesis for the evolution of metamorphosis

Jason Hodin

Hopkins Marine Station, Pacific Grove, CA (USA)



What is metamorphosis? Is it animal-specific or not?



The search for neuronal transcripts involved in the metamorphic transition of the sea hare Aplysia californica (Mollusca)

Andreas Heyland and Leonid L. Moroz

University of Florida, Whitney Laboratory, St. Augustine, FL (USA)


Signals mediating rapid loss of cell adhesion in metamorphosis

Anthony Pires

Dickinson College, PO Box 1773, Carlisle, PA 17013


Delay of metamorphosis in solitary ascidians: Genetics, morphology, and ecology

Molly Jacobs

Friday Harbor Laboratories; University of Washington, WA (USA)


Hormones translate environmental information to time amphibian metamorphosis

Robert Denver and Erica Crespi

University of Michigan, Ann Harbor, MI (USA)


coffee break


Lamprey metamorphosis and a theory on the evolution of adult life history types

John Youson

University of Toronto, Toronto, ON (CANADA)


Juvenile hormone as an effector of metamorphosis and life history transitions

Thomas Flatt,

Brown University, Providence, RI (USA)


An ancestral role for the metamorphosis-determining gene, broad in the direct-developing milkweed bug

Deniz F. Erezyilmaz, Lynn M. Riddiford and James W. Truman.

University of Washington, Seattle, WA (USA)



Contributed talks and posters associated with the symposium


TALKS: Saturday, January 7 - Great West Hall

13:00 65.1 Adam M. Reitzel; Sullivan, J.C.; Finnerty, J.R. Metamorphosis in the Life history of a parasitic sea anemone, Edwardsiella lineata
13:20 65.2 Edwards, T.M.; Moore, B.C.; Guillette, L.J. Metamorphic sex change: Evolutionary insight for endocrine disruption studies
13:40 65.3 Miller, MF; Okada, R; Ito, Y; De Groef, B; Yamamoto, K; Denver, RJ; Kikuyama, S Involvement of the corticotropin-releasing factor (CRF) type 2 receptor in CRF-induced thyrotropin release from the tadpole pituitary
14:00 65.4 Krista A. Mccoy; Alison M. Amick Metamorphosis and reproductive growth and development
14:20 65.5 Erica J Crespi; Robert J. Denver Conserved and novel functions of leptin in the South African clawed frog (Xenopus laevis)
14:40 65.6 Michael E. Baker Role of the environment on the evolution of signal transduction proteins and metamorphosis



POSTERS: Saturday, January 7  -  3:00-5:00pm Exhibit Hall  (poster session P3)

P3.82  Rozman, R.; Menon, J.M.  Effects of retinol and phytol on oxidative stress during anuran metamorphosis and regeneration
P3.83  Ollikainen, N.; Chandsawangbhuwana, C.  Evolution of ecdysone and thyroid hormone receptors
P3.84  Tanaka, K; Truman, JW Expression of patterning genes in the larval and the adult legs of Manduca sexta
P3.85  Nicholas Goehner; Hans Kelstrup; Lisa Kvalheim; Kari Zumwalt; Deniz Erezyilmaz; Lynn Riddiford  The search for the transcription factor Broad in non-insectan arthropods
P3.86  Samuel Fox; Laurence Von Kalm  Preliminary characterization of three genes with potential roles linking the RhoA signaling pathway to the ecdysone response in Drosophila epithelia
P3.87  Scott Santagata  The significance of neuromuscular anatomy and metamorphosis in the larval and juvenile body plans of phoronids and brachiopods
P3.88  Hens, M.D.; Fowler, K.A.; Burrows, B.J.; Deal, A.M.; Leise, E.M.  Neural cell birth and the characterization of larval nitric oxide synthase expression and activity in the caenogastropod Ilyanassa obsoleta
P3.89  Svetlana A. Maslakova; Matz, M. V.  Evolution of larval development in nemerteans (phylum Nemertea)






Selected References:

1. Heyland, A., Hodin, J., and Reitzel, A. M. (2005). Hormone signaling in evolution and development: a non-model system approach. Bioessays 27, 64-75.

2. Elinson RP. Direct Development: an Alternative Way to Make a Frog. Genesis 2001;29(2):91-95.

3. Truman JW, Riddiford LM. The origins of insect metamorphosis. Nature 1999;401(6752):447-52.

4. Hadfield MG, Strathmann MF. Variability, flexibility and plasticity in life histories of marine invertebrates. Oceanologica Acta 1996;19(3-4):323-334.

5. Youson JH. The Impact of Environmental and Hormonal Cues on the Evolution of Fish Metamorphosis. In: Hall BK, Pearson RD, Müller GB, editors. Environment, Development, and Evolution : Toward a Synthesis. Cambridge, London: MIT Press; 2003. p 239-277.