RRC ID 51571
Author Iwasaki M, Kuroda J, Kawakami K, Wada H.
Title Epidermal regulation of bone morphogenesis through the development and regeneration of osteoblasts in the zebrafish scale.
Journal Dev Biol
Abstract Bone is a connective tissue composed of many cell types, including osteoblasts. How bones acquire their unique size and shape during development remains poorly understood. Herein we investigated the molecular and cellular mechanisms of bone morphogenesis in the zebrafish scale by using transgenic lines to enable visualization of specific types of osteoblasts. We demonstrate that the zebrafish scale contains three distinct types of osteoblasts: (i) a monolayer of central osteoblasts along the inner surface of scales; (ii) marginal osteoblasts elongated along the scale edge; and (iii) submarginal osteoblasts located between the central and marginal osteoblast populations. The size of the central osteoblasts increases progressively during development, suggesting that scale growth is mediated primarily by cell growth rather than the recruitment of new osteoblasts. In addition, the total number of central osteoblasts increases in regenerated scales and is correlated with scale size, possibly allowing for the rapid growth of regenerating scales. Moreover, osteoblast proliferation is not detected during regeneration, suggesting that the osteoblasts originate from post-mitotic precursor cells. Sonic hedgehog a (shha) is expressed in the epidermal cells that make contact with the marginal osteoblasts. Pharmacological inhibition of Hedgehog (Hh) signaling during regeneration reduces the number of marginal osteoblasts and interferes with scale growth, indicating that epidermis-derived Shh regulates scale regeneration. Finally, genetic inhibition of Wnt/planar cell polarity (PCP) signaling in the epidermis results in misorientation of scales with regard to the body axis. These results reveal a novel role for the epidermis in the regulation of bone patterning, namely the regeneration of osteoblasts and directional bone growth.
Volume 437(2)
Pages 105-119
Published 2018-5-15
DOI 10.1016/j.ydbio.2018.03.005
PII S0012-1606(17)30582-1
PMID 29524434
MeSH Animals Body Patterning / genetics Bone Development / genetics* Bone Development / physiology Epidermis / metabolism* Gene Expression Regulation, Developmental Hedgehog Proteins / metabolism Immunohistochemistry In Situ Hybridization Osteoblasts / cytology* Osteoblasts / physiology Regeneration / genetics* Regeneration / physiology Signal Transduction Wnt Signaling Pathway / physiology Zebrafish / genetics Zebrafish Proteins / genetics Zebrafish Proteins / metabolism
IF 2.936
Times Cited 14