IAP genes partake weighty roles in the astogeny and whole body regeneration in the colonial urochordate Botryllus schlosseri

Studying Regeneration in Ascidians: An Historical Overview

“…Recently, Rosner and collaborators observed and studied an additional form of WBR in B. schlosseri, termed "budectomy induced WBR." When, in a colony at takeover (the phase in which the adult zooids are being resorbed and replaced by their primary buds), all the buds are surgically removed leaving only old zooids undergoing resorption, new budlets can develop from the latter [53]. In this view, even the experiments performed on B. schlosseri colonies by Majone in 1977 can be considered as WBR [54].…”

A pan‐metazoan concept for adult stem cells: the wobbling Penrose landscape

“…Further, the literature reveals cases where these ASCs not only express genes associated with germline stem cells, but are also able to differentiate into somatic cells or gametes, indicating the lack of strict boundaries between somatic/germline lineages. Examples include sponge archaeocytes and choanocytes (Fierro‐Constaín et al ., 2017 ; Funayama, 2018 ), hydrozoan i‐cells (Bode, 1996 ), flatworm and acoel neoblasts (Shibata, Rouhana & Agata, 2010 ; Chiodin et al ., 2013 ; Lai & Aboobaker, 2018 ), the posterior stem cells of the annelid growth zone (Giani et al ., 2011 ; Gazave et al ., 2013 ; Kozin & Kostyuchenko, 2015 ) and tunicate haemoblasts (Magor et al ., 1999 ; Stoner, Rinkevich & Weissman, 1999 ; Laird et al ., 2005 ; Voskoboynik et al ., 2007 ; Rosner et al ., 2009 ; Brown et al ., 2009 a ; Rinkevich, 2017 ; Rosner, Kravchenko & Rinkevich, 2019 ; Kassmer et al ., 2020 ).…”

“…As in the vertebrates (Lander, 2009 ), the essence of ASC stemness cannot be distilled down to a single shared molecular fingerprint, further highlighted by the co‐expression of somatic/germ stem cell signatures in invertebrate ASCs (Table 1 ), wherever these ASCs have been studied. This includes the expression of genes such as POU , SOX , Piwi , Bruno , Vasa and Pl10 orthologues in a number of metazoan ASCs, including sponge archaeocytes and choanocytes (Funayama, 2008 , 2018 ; Fierro‐Constaín et al ., 2017 ), hydrozoan i‐cells (Seipel et al ., 2004 ; Rebscher et al ., 2008 ; Leclère et al ., 2012 ), neoblasts of acoels and planarians (Guo, Peters & Newmark, 2006 ; Pfister et al ., 2008 ; De Mulder et al ., 2009 b ; Önal et al ., 2012 ), tunicate ASCs (Sunanaga, Watanabe & Kawamura, 2007 ; Rosner et al ., 2009 , 2019 ; Rinkevich et al ., 2010 ), putative stem cells from annelid growth zones (Rebscher et al ., 2007 ; Giani et al ., 2011 ; Gazave et al ., 2013 ), and presumably in regenerating nemertean tissues (Xu & Sun, 2020 ). This toti/pluripotency in non‐vertebrate phyla maintains functions such as gametogenesis, embryogenesis, homeostasis, asexual reproduction and regeneration (Fierro‐Constaín et al ., 2017 ), supporting the idea of global conservation in pluripotency‐associated genes for day‐to‐day needs (Fig.…”

Stem Cells and Innate Immunity in Aquatic Invertebrates: Bridging Two Seemingly Disparate Disciplines for New Discoveries in Biology

“…Test cells are of maternal origin and are first detected during early oogenesis ( 155 ). They express markers that can be associated with immune defense but also with the stem lineages: (i) DDX1 ( 156 ) known to function as sensors of viral and bacterial RNAs and in inhibition of virus replication ( 157 , 158 ); (ii) a IAP orthologue [IAP28 ( 159 ); Figure 6 ] that was correlated with cell proliferation control ( 160 ) and activation of caspases leading to apoptosis, depending on its subcellular location; (iii) Vasa and DDX3 (PL10), RNA helicases highly associated with soma/germ stem cells and germ lineages [( 156 , 161 ); Figure 6 ]. PL10 is also a modulator of the NF-κB pathway, known to be involved in responses to stress and viral/bacterial infections.…”