Bone Morphogenetic Protein Signaling Restricts Proximodistal Extension of the Ventral Fin Fold

Jun Ka; Jun-Dae Kim; Boryeong Pak; Orjin Han; Woosoung Choi; Hwan Kim; Suk-Won Jin

doi:10.3389/fcell.2020.603306

Bone Morphogenetic Protein Signaling Restricts Proximodistal Extension of the Ventral Fin Fold

Front Cell Dev Biol. 2020 Nov 30:8:603306. doi: 10.3389/fcell.2020.603306. eCollection 2020.

Authors

Jun Ka¹, Jun-Dae Kim^{2

3}, Boryeong Pak¹, Orjin Han¹, Woosoung Choi¹, Hwan Kim⁴, Suk-Won Jin^{1

2}

Affiliations

¹ School of Life Sciences, Cell Logistics Research Center, Gwangju Institute of Science and Technology, Gwangju, South Korea.
² Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, United States.
³ Center for Cardiovascular Regeneration, Department of Cardiovascular Sciences, Houston Methodist Research Institute, Houston, TX, United States.
⁴ Gwangju Institute of Science and Technology, Central Research Facilities, Gwangju, South Korea.

Abstract

Unpaired fins, which are the most ancient form of locomotory appendages in chordates, had emerged at least 500 million years ago. While it has been suggested that unpaired fins and paired fins share structural similarities, cellular and molecular mechanisms that regulate the outgrowth of the former have not been fully elucidated yet. Using the ventral fin fold in zebrafish as a model, here, we investigate how the outgrowth of the unpaired fin is modulated. We show that Bone Morphogenetic Protein (BMP) signaling restricts extension of the ventral fin fold along the proximodistal axis by modulating diverse aspects of cellular behaviors. We find that lack of BMP signaling, either caused by genetic or chemical manipulation, prolongs the proliferative capacity of epithelial cells and substantially increases the number of cells within the ventral fin fold. In addition, inhibition of BMP signaling attenuates the innate propensity of cell division along the anteroposterior axis and shifts the orientation of cell division toward the proximodistal axis. Moreover, abrogating BMP signaling appears to induce excessive distal migration of cells within the ventral fin fold, and therefore precipitates extension along the proximodistal axis. Taken together, our data suggest that BMP signaling restricts the outgrowth of the ventral fin fold during zebrafish development.

Keywords: BMP signaling; anisotropic growth; unpaired fin; ventral fin fold; zebrafish.