...Izumi Oda; Yutaka Satou ABSTRACT Ascidian larval muscle cells present a classic example of autonomous development. A regulatory mechanism for these cells has been extensively investigated, and the regulatory gene circuit has been documented from maternal factors to a muscle-specific gene...

...Agnès Roure; Rafath Chowdhury; Sébastien Darras ABSTRACT The most anterior structure of the ascidian larva is made of three palps with sensory and adhesive functions essential for metamorphosis. They derive from the anterior neural border and their formation is regulated by FGF and Wnt. Given...

... by The Company of Biologists Ltd 2022 Highlighted Article: Spindle assembly checkpoint (SAC) acquisition is likely specific to Phallusia mammillata embryos, whereas modulation of SAC efficiency in SAC proficient stages depends on cell fate and cell size. Mitosis Ascidian Spindle assembly...

.... In ascidian embryos, cell lineages do not vary among individuals, and rounds of the cell cycle are determined according to cell lineages. Notochord and muscle cells stop dividing after eight or nine rounds of cell division depending on their lineages. In the present study, we showed that a Cdk inhibitor...

...Deli Yu; Izumi Oda-Ishii; Atsushi Kubo; Yutaka Satou ABSTRACT Striated muscle cells in the tail of ascidian tadpole larvae differentiate cell-autonomously. Although several key regulatory factors have been identified, the genetic regulatory pathway is not fully understood; comprehensive...

...Miki Tokuoka; Kenji Kobayashi; Yutaka Satou ABSTRACT The transcriptional repressor Snail is required for proper differentiation of the tail muscle of ascidian tadpole larvae. Two muscle lineages (B5.1 and B6.4) contribute to the anterior tail muscle cells, and are consecutively separated from...

... of the pharyngeal endoderm, in the ascidian Ciona intestinalis . We found that knockout of Hox1 causes posterior-to-anterior transformation of the endostyle identity, and that Hox1 represses Otx expression and anterior identity, and vice versa. Furthermore, alteration of the regional identity of the endostyle...

...Rosaria Esposito; Hitoyoshi Yasuo; Cathy Sirour; Antonio Palladino; Antonietta Spagnuolo; Clare Hudson ABSTRACT In terms of their embryonic origins, the anterior and posterior parts of the ascidian central nervous system (CNS) are associated with distinct germ layers. The anterior part...

...://www.biologists.com/user-licence-1-1/ Summary: Live imaging of neural tube morphogenesis in Ciona uncovers roles for FGF and Nodal signaling in controlling the intercalation and stacking behaviors of cells. FGF Nodal Neurulation Morphogenesis Ascidian Intercalation National Institutes...

...Kaoru S. Imai; Clare Hudson; Izumi Oda-Ishii; Hitoyoshi Yasuo; Yutaka Satou Many animal embryos use nuclear β-catenin (nβ-catenin) during the segregation of endomesoderm (or endoderm) from ectoderm. This mechanism is thus likely to be evolutionarily ancient. In the ascidian embryo, nβ-catenin...

...Eileen Wagner; Alberto Stolfi; Yoon Gi Choi; Mike Levine The anterior-most ectoderm of ascidian larvae contains the adhesive papillae, or palps, which play an important role in triggering the metamorphosis of swimming tadpoles. In Ciona intestinalis , the palps consist of three conical protrusions...

...Nicolas Haupaix; Alberto Stolfi; Cathy Sirour; Vincent Picco; Michael Levine; Lionel Christiaen; Hitoyoshi Yasuo ERK1/2 MAP kinase exhibits a highly dynamic activation pattern in developing embryos, which largely depends on fibroblast growth factor (FGF) signals. In ascidian embryos, FGF-dependent...

... that the RA- Hox1 network also functions in the epidermal ectoderm of chordates. Here, we show that in the urochordate ascidian Ciona intestinalis , RA- Hox1 in the epidermal ectoderm is necessary for formation of the atrial siphon placode (ASP), a structure homologous to the vertebrate otic placode. Loss...

...Clare Hudson; Moly Ba; Christian Rouvière; Hitoyoshi Yasuo Ascidians are members of the vertebrate sister group Urochordata. Their larvae exhibit a chordate body plan, which forms by a highly accelerated embryonic strategy involving a fixed cell lineage and small cell numbers. We report a detailed...

... the temporal events in which ascidian pigment cell precursor specification and differentiation take place; however, they have not given many clues on the molecular events controlling these processes ( Darras and Nishida, 2001 ). Our results show that the FGF signaling pathway, via the MAPK cascade...

... rounds of ACD. In addition, inhibiting meiotic exit with Mos prevents pronuclear formation, cyclin A accumulation and maintains sperm-triggered Ca 2+ oscillations, all of which are hallmarks of the meiotic cell cycle in ascidians. It will be interesting to determine whether Mos availability in mammals...

...Alberto Stolfi; Michael Levine The visceral ganglion (VG) comprises the basic motor pool of the swimming ascidian tadpole and has been proposed to be homologous to the spinal cord of vertebrates. Here, we use cis-regulatory modules, or enhancers, from transcription factor genes expressed in single...

...Jason Tresser; Shota Chiba; Michael Veeman; Danny El-Nachef; Erin Newman-Smith; Takeo Horie; Motoyuki Tsuda; William C. Smith Ascidian larvae have a hollow, dorsal central nervous system that shares many morphological features with vertebrate nervous systems yet is composed of very few cells. We...

... (ACD). However, during ACD it remains unknown how the orientation of the mitotic spindle is regulated by cortical polarity cues until furrowing begins. In ascidians, the cortical centrosome-attracting body (CAB) generates three successive unequal cleavages and the asymmetric segregation of 40 localized...

... in the evolution of morphological diversity, as well as in the establishment of the body plan, little is known about the function of Hox genes in invertebrates, except for in insects and nematodes. The present study addresses the role of Hox genes in body patterning during the larval development of the ascidian...