Curator of Invertebrate Zoology in the Museum of Comparative Zoology
Faculty Support: Jennifer Thomson
Most animals are able to repair wounds and many can regenerate extensively, re-growing organs or even entire body plans from small fragments. Very little is known about how wounding results in repair and/or regeneration, or whether these mechanisms are similar across diverse animal species. We are taking an integrative approach for studying the wound response and stem cell biology during regeneration in an evolutionary framework by using a broad range of techniques including transcriptional profiling and lineage tracing.
We have developed the three-banded panther worm, Hofstenia miamia, as a new model acoel species for studies of regeneration. Acoels are likely to be the earliest lineage of animals with bilateral symmetry (bilaterians), and are therefore phylogenetically well-placed to inform questions about the evolution of regenerative mechanisms. Studies of Wnt and Bmp signaling pathways inHofstenia regeneration revealed that the mechanisms for patterning new tissue along the anterior-posterior and dorsal-ventral axes are conserved between acoels and planarians, a bilaterian lineage that is distantly related to acoels. This finding raises the possibility that highly conserved molecular genetic processes could underlie other aspects of regeneration, such as the regulation of stem cell differentiation or renewal.
We are using the many advantages of Hofstenia as a model regenerative species (e.g., robust regeneration capacity, RNAi that can be administered by soaking, tools for studying gene function, ability to isolate stem cells) to identify genes that control regeneration. Hofstenia produces accessible embryos that enable comparisons of regeneration and development, and provide a unique opportunity to use gene-delivery and genome-editing tools to study regeneration. Furthermore, these studies will complement those in other regenerative systems and enable us to identify conserved mechanisms. Because essential components of a process tend to be conserved over the course of evolution, identifying regenerative pathways shared by many species would be a powerful method to uncover as yet unknown regulators of regeneration.
A.R. Gehrke and Srivastava, M. Neoblasts and the evolution of whole-body regeneration. Curr. Opin. Genet. Dev., 40:131–37, 2016.
Lyons, D.C., M.Q. Martindale and M. Srivastava (2014). The cell's view of animal body-plan evolution. Integr. Comp. Biol. 54(4): 658-66. | PDF
Srivastava, M., K. Mazza-Curll, J.C. van Wolfswinkel, and P.W. Reddien (2014). Whole-body acoel regeneration is controlled by Wnt and Bmp-Admp signaling. Curr. Biol. 24(10): 1107-13. | PDF
- A. Ikmi, B. Gaertner, C. Seidel, Srivastava, M., J. Zeitlinger, and M.C. Gibson. (2014) Molecular evolution of the Yap/Yorkie proto-oncogene and elucidation of its core transcriptional program. Mol. Biol. Evol.31(6): 1375-90. | PDF
- M.L. Scimone, Srivastava, M., G. Bell, and P.W. Reddien (2011). A regulatory program for excretory system regeneration in planarians.Development, 138(20): 4387–98. | PDF
- Srivastava, M., O. Simakov, J. Chapman, B. Fahey, M.E. Gauthier, T. Mitros, G.S. Richards, C. Conaco, M. Dacre,U. Hellsten, C. Larroux, N.H. Putnam, M. Stanke, M. Adamska, A. Darling, S.M. Degnan, T.H. Oakley, D.C. Plachetzki, Y. Zhai, M. Adamski, A. Calcino, S.F. Cummins, D.M. Goodstein, C. Harris, D.J. Jackson, S.P. Leys, S. Shu, B.J.Woodcroft, M. Vervoort, K.S. Kosik, G. Manning, B.M. Degnan, and D.S. Rokhsar (2010). The Amphimedon queenslandica genome and the evolution of animal complexity. Nature, 466(7307): 720–726. | PDF
- Srivastava, M., C. Larroux, D. Lu, K. Mohanty, J. Chapman, B. Degnan, and D. Rokhsar (2010). Early evolution of the LIM homeobox gene family. BMC Biology, 8(4). | PDF
- H.Q. Marlow, Srivastava, M., D.Q. Matus, D. Rokhsar, and M. Q. Martindale (2009). Anatomy and development of the nervous system ofNematostella vectensis, an anthozoan cnidarian. Dev. Neurobiol., 69(4): 235–54. | PDF
- Srivastava, M., E. Begovic, J. Chapman, N. H. Putnam, U. Hellsten, T. Kawashima, A. Kuo, T. Mitros, M.L. Carpenter, A.Y. Signorovitch, M.A. Moreno, K. Kamm, J. Grimwood, J. Schmutz, H. Shapiro, I. V. Grigoriev, L.W. Buss, B. Schierwater, S. Dellaporta, and D. Rokhsar (2008). The Trichoplax genome and the nature of placozoans. Nature, 454(7207): 955–960. | PDF
Books and Book Chapters
D.C. Lyons, Srivastava, M., and D.Q. Matus. Evolution of developmental mechanisms controlling cell fate. In K. Sears and R. Kliman (Eds.), Encylcopedia of Evolutionary Biology. Oxford: Academic Press. 1:409–19, 2016.
Srivastava, M. A comparative genomics perspective on the origin of multicellularity and early animal evolution. In I. Ruiz-Trillo and A. Nedelcu (Eds.), Evolutionary Transitions to Multicellular Life. Springer. pages 269–99, 2015.
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