Evolution of early branching metazoans
Studying the molecular mechanisms governing the evolution of animals
Currently, our perception of animal is highly bilateral (all bilaterally symmetrical animals) biased. In order to gain broader perceptive on the evolution of animals, one must look into a wider range of extant species such as non-bilaterian animals that represent lineages that diverged more than 600 million years ago from the rest of the Metazoa. These include the phyla Porifera (sponges), Ctenophora (comb jellies), Placozoa (Trichoplax) and Cnidaria (sea anemones, corals, hydroids and jellyfish). Studying these animals can give researchers a new perspective about the evolution of animal.
Origins and evolution of miRNAs at the dawn of metazoans
Over the last two decades, it has become evident that miRNAs play a central role in various biological processes in both plants and animals, which are vital for growth and development. To achieve a greater understanding of miRNA evolutionary origin, we need to study miRNA mechanisms in the groups that date back to the beginning of animal life (sponges, comb jellies, placozoans and cnidarians). During my postdoctoral research at Prof. Yehu Moran’s lab (The Hebrew University of Jerusalem, Israel), I studied how posttranscriptional gene regulation by small RNAs is carried out in the sea anemone Nematostella vectensis, and this study has shed new light on the evolution of small RNA biogenesis in Metazoa. As part of my long-term scientific quest, I continued exploring the molecular mechanism underlying the posttranscriptional gene regulation using non-bilaterian animals. After I joined MBA, I expanded my research towards studying the evolution of small RNA biogenesis in the sponge. Sponge occupy a key phylogenetic position to investigate the origin and evolution of the miRNA pathway in the animal kingdom. The main focus of this study is to understand the miRNA mechanisms of sponges and to reveal how miRNAs were produced and functioned in the first animals.
Evolutionary origin of apical organ in the marine ciliated larvae
The apical organ is a neurosensory structure engaged in sensing environmental cues to modulate swimming behaviour and metamorphosis of ciliated larvae. The evolutionary success of the planktonic larvae can be attributed to the apical sensory organ featured with neurons, which allows integrating multiple sensory inputs to produce global responses. The origin of the nervous system is probably interlinked with the evolution of the larval sensory organ. Cnidarians like the sea anemone Nematostella vectensis belong to one of the first metazoan lineages to evolve ciliated larvae with a true apical organ integrated with larval neurons. This project investigates the functional mechanism and signalling pathways associated with the larval sensory-ciliomotor nervous system.
Lessons to learn on the origin of multicellularity over the sponge regeneration model
The factors that have driven the emergence of multicellular animals from their unicellular ancestors have yet to be addressed. Several studies on unicellular relatives of animals, including choanoflagellates, and ichthyosporeans have significantly contributed to understanding how unicellular organisms transform into multicellular structures such as colonial choanoflagellate. This suggests similar transitions may have taken place in the animal ancestors, which eventually evolved into a stable and functional multicellular animal. Sponges are the ancient extant branch of metazoans. Understanding their cellular behaviour during early regeneration, including the signalling molecules triggering the aggregation of cells, can provide a window into understanding the transition from unicellular to multicellular life forms. We explore the sponge regeneration system to identify the genetic features underlying the evolution of multicellularity.
- Praher D, Zimmermann B, Dnyansagar R, Miller DJ, Moya A, Modepalli V, Fridrich A, Sher D, Friis-Møller L, Sundberg P, Fôret S, Ashby R, Moran Y and Technau U. 2021. Conservation and turnover of miRNAs and their highly complementary targets in early branching animals. Proceedings of the Royal Society B: Biological Sciences 288(1945): 20203169. https://doi.org/10.1098/rspb.2020.3169
- Fridrich A, Modepalli V, Lewandowska M, Aharoni R, Moran Y. 2020. Unravelling the developmental and functional significance of an ancient Argonaute duplication. Nature communications, 11, Article number: 6187 https://doi.org/10.1038/s41467-020-20003-8
- A Soubigou, EG Ross, Y Touhami, N Chrismas, V Modepalli. 2020. Regeneration in sponge Sycon ciliatum mimics postlarval development. Development: dev.193714 https://doi.org/10.1242/dev.193714
- A Fridrich, V Modepalli, M Lewandowska, R Aharoni, Y Moran. 2020. Unravelling the developmental and functional significance of an ancient Argonaute duplication. BioRxiv https://doi.org/10.1101/2020.02.04.933887
- C Lefèvre, P Venkat, A Kumar, V Modepalli, KR Nicholas. 2019. Comparative analysis of milk microRNA in the therian lineage highlights the evolution of lactation. Reproduction, Fertility and Development 31 (7), 1266-1275 https://doi.org/10.1071/RD18199
- Kevin R Nicholas, V Modepalli, A P Watt, L A Hinds, A Kumar, C Lefevre, J A Sharp. 2019. Guiding Development of the Neonate: Lessons from Mammalia., Human Milk: Composition, Clinical Benefits and Future Opportunities 90, 203-215 https://doi.org/10.1159/000490319
- MY Sachkova, YY Columbus-Shenkar, A Fridrich, V Modepalli, K Sunagar, Y Moran. 2019. Starlet sea anemone venom: Dynamics across the life cycle., TOXICON-OXFORD- 158 (1), S37-S37 https://doi.org/10.1016/j.toxicon.2018.10.131
- V Modepalli, A Kumar, J A Sharp, N R Saunders, K R Nicholas & C Lefèvre. 2018. Gene expression profiling of postnatal lung development in the marsupial gray short-tailed opossum (Monodelphis domestica) highlights conserved developmental pathways and specific characteristics during lung organogenesis. BMC Genomics 19(1): 732. 10.1186/s12864-018-5102-2 https://doi.org/10.1186/s12864-018-5102-2
- V Modepalli, A Fridrich, M Agron, Y Moran. 2018. The methyltransferase HEN1 is required in Nematostella vectensis for microRNA and piRNA stability as well as larval metamorphosis. PLOS Genetics 14(8): e1007590. https://doi.org/10.1371/journal.pgen.1007590
- Columbus-Shenkar, Y. Y., M. Y. Sachkova, J. Macrander, A. Fridrich, V. Modepalli, A. M. Reitzel, K. Sunagar and Y. Moran (2018). Dynamics of venom composition across a complex life cycle. eLife. 7: e35014.2. PMC5832418
- Praher D, Zimmermann D, Genikhovich G, Columbus-Shenkar Y, Modepalli V, Aharoni R, Moran Y and Technau U (2017). Characterization of the piRNA pathway during development of the sea anemone Nematostella vectensis. RNA Biology. PMC5731801
- Modepalli, V. and Y. Moran (2017). Evolution of miRNA tailing by 3′ terminal uridylyl transferases in Metazoa. Genome Biology and Evolution. evx106. PMC5509036.
- Mauri, M., M. Kirchner, R. Aharoni, C. Ciolli Mattioli, D. van den Bruck, N. Gutkovitch, V. Modepalli, M. Selbach, Y. Moran and M. Chekulaeva (2016). Conservation of miRNA-mediated silencing mechanisms across 600 million years of animal evolution. Nucleic Acids Research. 45(2): 938-950. PMC5314787.
- Modepalli, V., L. A. Hinds, J. A. Sharp, C. Lefevre and K. R. Nicholas (2016). Marsupial tammar wallaby delivers milk bioactives to altricial pouch young to support lung development. Mechanisms of Development. 142: 22-29. PMC51 61226.
- Modepalli, V., L. A. Hinds, J. A. Sharp, C. Lefevre and K. R. Nicholas (2015). Role of marsupial tammar wallaby milk in lung maturation of pouch young. BMC Developmental Biology. 15: 16. PMC4377010.
- Modepalli, V., A. Kumar, L. A. Hinds, J. A. Sharp, K. R. Nicholas and C. Lefevre (2014). Differential temporal expression of milk miRNA during the lactation cycle of the marsupial tammar wallaby (Macropus eugenii). BMC Genomics. 15: 1012. PMC4247635.
- Modepalli, V. N., A. L. Rodriguez, R. Li, S. Pavuluri, K. R. Nicholas, C. J. Barrow, D. R. Nisbet and R. J. Williams (2014). In vitro response to functionalized self-assembled peptide scaffolds for three-dimensional cell culture. Peptide Science. 102(2): 197-205. doi: 10.1002/bip.22469. PMID: 24488709
- Sharp, J. A., S. Wanyonyi, V. Modepalli, A. Watt, S. Kuruppath, L. A. Hinds, A. Kumar, H. E. Abud, C. Lefevre and K. R. Nicholas (2017). The tammar wallaby: A marsupial model to examine the timed delivery and role of bioactives in milk. General and Comparative Endocrinology 244: 164-177. PMID: 27528357
- Sharp, Julie A., V. Modepalli, Enjapoori, Ashwantha, Abud, Helen E., Lefevre, Christophe and Nicholas, Kevin R. 2016, Milk: milk of monotremes and marsupials. Reference module in food sciences, Elsevier, pp.1-10. doi: http://dx.doi.org/10.1016/B978-0-08-100596-5.00910-0.
- Sharp, J. A., V. Modepalli, A. K. Enjapoori, S. Bisana, H. E. Abud, C. Lefevre and K. R. Nicholas (2014). Bioactive Functions of Milk Proteins: a Comparative Genomics Approach. Journal of Mammary Gland Biology and Neoplasia. 19(3-4): 289-302. PMID: 26115887
- Julie A. Sharp, Ashalyn Watt, Swathi Bisana, Vengama Modepalli, Stephen Wanyonyi, Amit Kumar, Joly Kwek, Rod Collins, Christophe Lefèvre & Nicholas, KR 2014, The Comparative Genomics of Monotremes, Marsupials, and Pinnipeds: Models to Examine the Functions of Milk Proteins, Milk Proteins: From Expression to Food, Elsevier, Amsterdam, The Netherlands. p. 75-112