The evolution of multicellular organisms is generally thought (and seems likely) to have been accompanied by the evolution of a stem cell system. Sponges, some of the early-evolved metazoans, have totipotent/pluripotent stem cells. Thus, uncovering the cellular and molecular bases of the sponge stem cells will not only be crucial for understanding the ancestral gene repertoire of animal stem cells, but will also give us clues for understanding the evolution of molecular mechanisms of maintaining multipotency (pluripotency) and differentiation ability during animal evolution. We have been working to clarify the molecular and cellular bases of the stem cell system of demosponges. Using an asexual reproduction system (gemmule hatching), the development of fully functional juvenile sponges from a group of stem cells alone, of a freshwater sponge, Ephydatia fluviatlis, we established methodologies for molecular studies and sequencing resources. Based on our results and previous histological studies, we proposed that the sponge stem cell systemconsists of two types of cells, archeocytes (mesenchymal pluripotent stem cells) and choanocytes (which generally function as food-entrapping cells but exhibit pluripotency in specific circumstances, for example, by undergoing meiosis to produce gametes). I would like to introduce our gene-expression and transcriptomic analyses of those two types of cells, especially archeocytes, and discuss the ancestral toolkit of animal stem cells and its biological significance.
The evolution of multicellular organisms is generally thought (and seems likely) to have been accompanied by the evolution of a stem cell system. Sponges, some of the early-evolved metazoans, have totipotent/pluripotent stem cells. Thus, uncovering the cellular and molecular bases of the sponge stem cells will not only be crucial for understanding the ancestral gene repertoire of animal stem cells, but will also give us clues for understanding the evolution of molecular mechanisms of maintaining multipotency (pluripotency) and differentiation ability during animal evolution. We have been working to clarify the molecular and cellular bases of the stem cell system of demosponges. Using an asexual reproduction system (gemmule hatching), the development of fully functional juvenile sponges from a group of stem cells alone, of a freshwater sponge, Ephydatia fluviatlis, we established methodologies for molecular studies and sequencing resources. Based on our results and previous histological studies, we proposed that the sponge stem cell systemconsists of two types of cells, archeocytes (mesenchymal pluripotent stem cells) and choanocytes (which generally function as food-entrapping cells but exhibit pluripotency in specific circumstances, for example, by undergoing meiosis to produce gametes). I would like to introduce our gene-expression and transcriptomic analyses of those two types of cells, especially archeocytes, and discuss the ancestral toolkit of animal stem cells and its biological significance.
2B9 - Building 2 GSA2018_APCC6 GSACC62018@canberra.edu.auTechnical Issues?
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