<p>Current Knowledge on Stem Cells in Ascidians</p>

Abstract

He is a member of the editorial board of the Invertebrate Survival Journal and the European Journal of Zoology, and is a founding member of the Italian Association of Developmental and Comparative Immunobiology (IADCI). His main research interests are the evolution of innate immunity and the study of the cellular and molecular basis of immune responses in marine invertebrates, with particular reference to the role of hemocytes/coelomocytes in immune defense and, more generally, in the stress response. Most of his studies were carried out using the colonial ascidian Botryllus schlosseri as a model organism. His interest in stem cells is directly related to their role in hematopoiesis, as they assure the continuous renewal of the circulating immunocytes of marine invertebrates. He is the chair of the COST Action 16203 MARISTEM "Stem cells of marine/aquatic invertebrates: from basic research to innovative applications" that supported the publication of this book. He is the author or co-author of more than 130 peer-reviewed publications in scientific journals, co-editor of scientific books, including "Lessons in immunity: from singlecell organisms to mammals" (Elsevier, 2016), and guest editor of Special Issues, including: "Ancient immunity. phylogenetic emergence of recognition-defence mechanisms" (Biology (Basel), 2020-2021).Baruch (Buki) Rinkevich has been a professor and senior scientist at the

Physiological changes during torpor favor association with Endozoicomonas endosymbionts in the urochordate Botrylloides leachii

“…Ascidians, or sea squirts (Tunicata), are a group of filter-feeding marine invertebrates that hold an important evolutionary position as a sister clade to the chordates ( Vanni et al, 2022 ). They present a wide range of torpor events in various colonial taxa ( Mukai et al, 1983 ; Turon, 1992 ; De Caralt et al, 2002 ; Hyams et al, 2017 ).…”

Improved Media Formulations for Primary Cell Cultures Derived from a Colonial Urochordate

“…Botryllus schlosseri (Chordata, Tunicata, Ascidiacea), a colonial urochordate of cosmopolitan distribution, serves as a valuable model organism in various scientific disciplines, including stem cell biology [ 14 , 15 ], which has garnered significant attention due to the exceptional cellular potentialities exhibited by various cell types from this species, such as multipotency and totipotency [ 5 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ], all of which hold great promise for in vitro applications. Colonies of B. schlosseri exhibit both tight asexual (referred to as blastogenesis) and sexual modes of reproduction [ 14 , 15 ].…”

“Keep on rolling”: circulating cells in a botryllid ascidian torpor

“…In botryllid ascidians, hemocytes exert a wide range of functions, including transportation and storage of nutrients (Cima et al, 2016), respiration (Ballarin and Cima, 2005), whole-body regeneration (Rinkevich et al, 1995;Rinkevich et al, 2007;Rinkevich et al, 2008), budding (Brunetti, 1976;Voskoboynik et al, 2007;Rinkevich et al, 2013), sexual reproduction (Blanchoud et al, 2018a), defense reactions (Rinkevich and Shapira, 1998;Cima et al, 2016;Ballarin et al, 2021), and tunic generation (Hirose et al, 1995). While B. leachii hemocyte compositions and morphologies were investigated previously using cytological, histochemical, and histoenzymatical analyses (Cima et al, 2001;Cima et al, 2016;Blanchoud et al, 2017;Cima, 2022;Zeng et al, 2022), the classification of hemocyte cell types and their functions remains ambiguous (Vanni et al, 2022). The different classification criteria, the lack of unified terminology, the high structural diversity of hemocytes among ascidian species, and poorly documented intermediate stages of differentiation and dissimilarity of identical hemocytes resulting from different fixation methods (Burighel et al, 1997;Cima et al, 2001;Blanchoud et al, 2017) have all contributed to the challenges of cell classification and comparative studies.…”