Current Knowledge on Stem Cells in Ascidians
Abstract
Tunicates, the sister group of vertebrates, are cosmopolitan marine filter-feeding organisms. Various species pertaining to this chordate subphylum have been the subject of several researches, as they show remarkable stem cell mediated regenerative abilities and, in colonial species, a continuous development of new individuals by asexual reproduction. In this chapter, we highlight the current knowledge on the biology of stem cells and their involvement in development and regeneration of both solitary and colonial tunicates, with particular reference to ascidians. In addition, we put a special focus on the methods used to identify stem cells and their niches, their involvement in biological phenomena such as budding, torpor, aging and chimerism, the cellular and molecular basis of regeneration as well as on the possible future directions in the study of stemness in ascidians.
