Developing a system to study stem cell biology during whole body regeneration in sea star larva
Faculty Mentor Name
Tara Fresques
Research or Creativity Area
Natural Sciences
Abstract
Regeneration, the ability to recover and grow back portions of the body, is seen all throughout the animal kingdom. However, regeneration ability greatly varies across phyla. Whole body regeneration (WBR) is the most robust type of regeneration, and very few species possess this ability. One phylum that does possess WBR is Echinodermata, including sea urchins, sea cucumbers, brittle stars, and the subject of this study, sea stars (Asteroidea). Echinodermata are often the focus of regeneration studies due to their close proximity to humans in evolutionary history and similar embryonic development, with both being in the deuterostome clade. Patiria miniata, specifically in their larval phase, is a powerful model organism to study WBR for a multitude of reasons. The larva are small and optically clear. Further, it is easy to produce millions of sea star larva in the laboratory that are amenable to various molecular assays. In regards to WBR in sea stars, the type of stem cells involved, the location of those stem cells, and the timing of gene expression related to a stem cell fate are largely unknown. The focus of this study is as a proof of concept and to create a protocol in order to explore these unknowns to gain a deeper understanding of WBR in sea stars and deuterostomes as a whole.
Purpose
Regeneration, the ability to recover and grow back portions of the body, is seen all throughout the animal kingdom. However, regeneration ability greatly varies across phyla. Whole body regeneration (WBR) is the most robust type of regeneration, and very few species possess this ability. One phylum that does possess WBR is Echinodermata, including sea urchins, sea cucumbers, brittle stars, and the subject of this study, sea stars (Asteroidea). Echinodermata are often the focus of regeneration studies due to their close proximity to humans in evolutionary history and similar embryonic development, with both being in the deuterostome clade. Patiria miniata, specifically in their larval phase, is a powerful model organism to study WBR for a multitude of reasons. The larva are small and optically clear. Further, it is easy to produce millions of sea star larva in the laboratory that are amenable to various molecular assays. In regards to WBR in sea stars, the type of stem cells involved, the location of those stem cells, and the timing of gene expression related to a stem cell fate are largely unknown. The focus of this study is as a proof of concept and to create a protocol in order to explore these unknowns to gain a deeper understanding of WBR in sea stars and deuterostomes as a whole.
Results
We developed many laboratory protocols necessary to use sea star larva to understand molecular mechanisms that contribute to whole body regeneration, including a system to rear larva long-term, a system to produce larval food (algae), a system to perform larval bisections, and a system to use RT-qPCR to assess the expression of molecules related to stem cell biology. Our preliminary data suggests that the stem cell marker, telomerase, is expressed in larva prior to regeneration. 6-days post bisection we find that the posterior halves express more telomerase than the anterior halves.
Significance
We have developed a system to understand molecular features related to whole body regeneration in larval sea stars. Future studies can use this system to determine the unique features of stem cells in sea stars that allow them to be capable of this amazing feat. We can use this knowledge to better inform regenerative therapies in humans.
Developing a system to study stem cell biology during whole body regeneration in sea star larva
Regeneration, the ability to recover and grow back portions of the body, is seen all throughout the animal kingdom. However, regeneration ability greatly varies across phyla. Whole body regeneration (WBR) is the most robust type of regeneration, and very few species possess this ability. One phylum that does possess WBR is Echinodermata, including sea urchins, sea cucumbers, brittle stars, and the subject of this study, sea stars (Asteroidea). Echinodermata are often the focus of regeneration studies due to their close proximity to humans in evolutionary history and similar embryonic development, with both being in the deuterostome clade. Patiria miniata, specifically in their larval phase, is a powerful model organism to study WBR for a multitude of reasons. The larva are small and optically clear. Further, it is easy to produce millions of sea star larva in the laboratory that are amenable to various molecular assays. In regards to WBR in sea stars, the type of stem cells involved, the location of those stem cells, and the timing of gene expression related to a stem cell fate are largely unknown. The focus of this study is as a proof of concept and to create a protocol in order to explore these unknowns to gain a deeper understanding of WBR in sea stars and deuterostomes as a whole.
