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.
Germline plays a unique role in gamete production, heredity and evolution. Therefore, understanding the mechanisms supporting germline is a major challenge in developmental and evolutionary biology. The origin of germline segregation and the establishment of the piRNA pathway in the germline is still a debatable question. Among metazoans, the Porifera, Ctenophora and Cnidaria (sea anemones, corals, hydroids and jellyfish) are the most basal diverged animal phyla originated nearly 600 million years ago. In Porifera, the border between the germline and somatic stem cells is narrow, as both are produced from pluripotent archaeocytes. In cnidarian Nematostella vectensis, the gametes are produced from a committed germline, similarly to bilaterian animals. In cnidarian animals, the piRNA pathway components are also expressed in the germline, however, their functional role in maintaining gametogenesis remained obscure.
We aim to investigate the functional role of the piRNAs in maintaining somatic and germ cells in Nematostella. From this study, we get insights into piRNA functional link in regeneration, development and reproduction of Nematostella.
Acquisition of phototrophic endosymbionts constitutes a key ecological innovation in the evolution of corals, permitting these animals to flourish in oligotrophic waters. Due to recent global environmental changes the coral reefs are declined worldwide, that is associated with loss of endosymbiotic relation known as coral bleaching. Corals have different thermal tolerance in related to their local environmental conditions, while anemones like Anemonia viridis and Aiptasia mutabilis have broad geographical distribution with extremely different temperature conditions. Anemones in the Mediterranean and Red Sea (27°C - 35°C) are known for enhanced thermal tolerance when compared to counterparts from mild temperature habitats like coastal regions of the United Kingdom (15°C - 20°C). Phenotypic plasticity and genotype by environment interactions are key elements in defining the survival success of a species in broad ecological niches. These anemones possibility evolved with novel adaptations enabling to survive in higher stress environments and these adaptations support for evolution of thermal resistant genotype.
We aim to understand the genetic factors that contribute to thriving the anemone strain in thermal stress conditions by comparison of anemones from geographically distinct locations with different thermal tolerance. This study will enable us to understand the influence of environmental conditions on genotype.
- Modepalli V, Kumar A, Sharp JA, Saunders NR, Nicholas KR, Lefèvre C (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. PMC6173930
- Modepalli V, Fridrich A, Agron M, Moran Y (2018) The methyltransferase HEN1 is required in Nematostella vectensis for microRNA and piRNA stability as well as larval metamorphosis. PLOS Genet. 14: e1007590. PMC6114907
- 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