Dr. Aldine Amiel is an EMBO (European Molecular Biology Organization) Postdoctoral Fellow working with the Seaver Group at Kewalo Marine Lab. She is also one of three co-founders of the non-profit organization Kahi Kai, a group committed to promoting communication and interaction among students, scientists, and anyone interested in the endangered marine world.
For her Master's degree at the IBDML in Marseille, Dr. Amiel worked on the ascidian model system Ciona intestinalis, investigating the formation of the peripheral nervous system of the tadpole larva. For her doctoral research in Molecular, Cellular and Developmental Biology at the Pierre and Marie Curie University (Paris VI), Dr. Amiel studied the establishment of the primary polarity in immature eggs of a cnidarian model organism, Clytia hemisphaerica, and the role of the Mos kinase during meiotic maturation
"I am interested in understanding, at the cellular and molecular levels, the evolution of the diversity of animal forms seen within the metazoans", says Dr. Amiel. "This field of evolutionary developmental biology, or EvoDevo, combines two major biology fields important for our understanding of the origin of animal biodiversity and how the complex biological processes at the origin of the embryonic development appear and evolved during animal Evolution."
In this field, researchers like Dr. Amiel take a comparative approach by contrasting developmental processes between diverse groups of animals, so obtaining information from many different animal groups is important. Many of the molecular mechanisms involved in embryonic development have been studied extensively in deuterostomes and ecdysozoans, two of the three large groups that make up the Bilateria. However, the third bilaterian group, the Lophotrochozoa, has been until now a largely neglected clade, which has left a gap in our understanding of animal evolution.
In the Seaver Lab, Dr. Amiel's current research project focuses on the lophotrochozoans and the molecular mechanisms involved in establishing the body axes – a critical developmental step in determining the final body plan – during early embryonic development.
"When a complex multi-cellular, multi-layered larva or adult body develops from a "simple" single-celled egg, many crucial biological events occur, including the fundamental establishment of the different body axes – antero-posterior, dorso-ventral, and left-right," notes Dr. Amiel. "Specifically, I am looking at the evolution and function of the Wnt signaling complement and MAPK pathway to understand how they are involved in establishing the main body axes during early development of a marine annelid, the polychaete Capitella teleta.
The emerging model system Dr. Amiel is using for her research, Capitella teleta, is a small, segmented worm that lives in the mud. Although it appears to be quite a humble animal, this little worm has the potential to contribute much to our knowledge about early embryonic development in spiralians, particularly about the molecular signals underlying the formation of the so-called "organizer", a region of the vertebrate embryo that is important in directing formation of the body plan.
During early development, the body axes and diverse cell types arise though a series of inductive cellular interactions via signaling pathways and cell movements that arrange the body tissues in their proper places with respect to each other. In vertebrates, there is a specialized group of cells, the "organizer", which signals inductively to surrounding cells, regulates tissue movements during gastrulation, and organizes a complete body plan. The formation of the "organizer" is a complex process regulated by distinct signaling pathways, including Wnt/βcat, TGFβ, and FGF/MAPK.
"It's interesting," notes Dr. Amiel, "that the two most studied ecdysozoans, Drosophila and C. elegans, appear to lack an organizer typical of vertebrates. However, some lophotrochozoan embryos appear to exhibit organizer-like activity during early development."
Experimental evidence from several spiralians (mainly molluscs), implicates one or several cells from the D quadrant lineage in the organization of the future axial properties of the embryo. The molecular mechanisms involved are not well understood; however recent studies on spiralian embryos have shown MAPK activation in one or multiple cells from the D quadrant lineage. MAPK activation in these specific cells is crucial for organizer identity and activity, and for the development of the antero-posterior and dorso-ventral body axes.
"Many of the crucial molecular pathways involved in important developmental processes are well-conserved from cnidarians to vertebrates, and it is likely that they share conserved developmental roles," Dr. Amiel points out. "In my project, I am trying to determine, first, if organizer activity is present or not in Capitella; and second, if there is an organizer, what are the similarities and/or differences in its organizing activity between annelids and molluscs. I am also interested in finding out which of the molecular signaling pathways, for example Wnt or MAPK, are important for organizer activity during early Capitella development."
"My diverse research experience examining various groups of the metazoan tree of life allowed me to learn from existing model organisms and to transfer the technical skills necessary to study an emerging model system, like Capitella, and to gain insight into metazoan body plan evolution," reflects Dr. Amiel.
"Overall, I hope that this investigation of the integration of signaling pathways to orchestrate early development in the lophotrochozoan Capitella teleta will help us to understand the evolutionary history of complex pathways during bilaterian evolution".