Modular co-option of cardiopharyngeal genes during non-embryonic myogenesis

Author(s)

Prunster, Maria Mandela ^[1] ; Ricci, Lorenzo ^{[1, 2]} ; Brown, Federico D. ^{[3, 4]} ; Tiozzo, Stefano ^[1]

Affiliation

^[1] Sorbonne Univ, CNRS, Lab Biol Dev Villefranche sur mer LBDV, F-06230 Villefranche Sur Mer - France

^[2] Harvard Univ, Dept Organism & Evolutionary Biol, 52 Oxford St, Cambridge, MA 02138 - USA

^[3] Univ Sao Paulo, Inst Biociencias, Dept Zool, BR-05508090 Sao Paulo, SP - Brazil

^[4] Univ Sao Paulo, Ctr Biol Marinha CEBIMar, BR-11612109 Sao Sebastiao, SP 11612109 - Brazil

• Document type: Journal article
• Source: EVODEVO; v. 10, MAR 5 2019.
• Web of Science Citations: 2

Abstract

Background: In chordates, cardiac and body muscles arise from different embryonic origins. In addition, myogenesis can be triggered in adult organisms, during asexual development or regeneration. In non-vertebrate chordates like ascidians, muscles originate from embryonic precursors regulated by a conserved set of genes that orchestrate cell behavior and dynamics during development. In colonial ascidians, besides embryogenesis and metamorphosis, an adult can propagate asexually via blastogenesis, skipping embryo and larval stages, and form anew the adult body, including the complete body musculature. Results: To investigate the cellular origin and mechanisms that trigger non-embryonic myogenesis, we followed the expression of ascidian myogenic genes during Botryllus schlosseri blastogenesis and reconstructed the dynamics of muscle precursors. Based on the expression dynamics of Tbx1/10, Ebf, Mrf, Myh3 for body wall and of FoxF, Tbx1/10, Nk4, Myh2 for heart development, we show that the embryonic factors regulating myogenesis are only partially co-opted in blastogenesis, and that markers for muscle precursors are expressed in two separate domains: the dorsal tube and the ventral mesenchyma. Conclusions: Regardless of the developmental pathway, non-embryonic myogenesis shares a similar molecular and anatomical setup as embryonic myogenesis, but implements a co-option and loss of molecular modules. We then propose that the cellular precursors contributing to heart and body muscles may have different origins and may be coordinated by different developmental pathways. (AU)

• FAPESP's process: 15/50164-5 - Stem cells, regeneration, and the evolution of coloniality in ascidians
• Grantee: Federico David Brown Almeida
• Support Opportunities: Research Grants - Young Investigators Grants