YOSHIDA Keita
   Department   School of Medicine, School of Medicine
   Position   Assistant Professor
Article types Original article
Language English
Peer review Peer reviewed
Title Hox13 is essential for formation of a sensory organ at the terminal end of the sperm duct in Ciona.
Journal Formal name：Developmental biology
Abbreviation：Dev Biol
ISSN code：1095564X/00121606
Domestic / ForeginForegin
Volume, Issue, Page 458(1),pp.120-131
Author and coauthor Tajima Yukako, Hozumi Akiko, Yoshida Keita, Treen Nicholas, Sakuma Tetsushi, Yamamoto Takashi, Sasakura Yasunori
Publication date 2020/02
Summary Species-specific traits are thought to have been acquired by natural selection. Transcription factors play central roles in the evolution of species-specific traits. Hox genes encode a set of conserved transcription factors essential for establishing the anterior-posterior body axis of animals. Changes in the expression or function of Hox genes can lead to the diversification of animal-body plans. The tunicate ascidian Ciona intestinalis Type A has an orange-colored structure at the sperm duct terminus. This orange-pigmented organ (OPO) is the characteristic that can distinguish this ascidian from other closely related species. The OPO is formed by the accumulation of orange-pigmented cells (OPCs) that are present throughout the adult body. We show that Hox13 is essential for formation of the OPO. Hox13 is expressed in the epithelium of the sperm duct and neurons surrounding the terminal openings for sperm ejection, while OPCs themselves do not express this gene. OPCs are mobile cells that can move through the body vasculature by pseudopodia, suggesting that the OPO is formed by the accumulation of OPCs guided by Hox13-positive cells. Another ascidian species, Ciona savignyi, does not have an OPO. Like Hox13 of C. intestinalis, Hox13 of C. savignyi is expressed at the terminus of its sperm duct; however, its expression domain is limited to the circular area around the openings. The genetic changes responsible for the acquisition or loss of OPO are likely to occur in the expression pattern of Hox13.
DOI 10.1016/j.ydbio.2019.10.028
PMID 31682808