Shaping the craniofacial skeleton of Mexican cavefish (Astyanax mexicanus); Role of Osteoblast and Osteoclast

Abstract

The vertebrate bony skeleton is remodelled continuously by bone deposition and reabsorption, which is essential for normal development, growth, repair and for the mineral homeostasis. Remodelling of the skeleton usually involves the removal of the bone by osteoclasts and the subsequent formation of new bone by osteoblasts. These remodelling mechanisms can be found in the teleost fish skeleton with special adaptation to the aquatic life. Most of the fish species have teeth in their craniofacial region and replace their dentitions though out the life which lead to continuous bone remodelling activity in the tooth‐bearing bones. The Mexican tetra (Astyanax mexicanus), is a small teleost fish that exists as two morphs; sighted and blind cave form. The degeneration of the eyes, result in the characteristics craniofacial phenotype in cavefish. However, little is known about the cellular mechanisms underlying the remodelling activity of the skeleton of this species. This study was designed to identify the cellular interactions during the development of craniofacial skeleton of Mexican cavefish. Histological and whole mount analysis was performed to compare the development of the skeleton in these two morphs. The cavefish showed delayed eruption of teeth in tooth‐bearing bones but has large jaw bones compared to the surface larval fish. Sites of bone resorption in the bony skeleton will be investigated by RNA in situ hybridization and ultrastructural analysis. Live bone staining techniques will be used to identify the pattern of bone deposition. This study will provide insights into the evolution of osteoblastic and osteoclastic cell activity and will highlight the use of this species as a model in mammalian skeletal disorders.Support or Funding InformationThis research was funded by the University of Manitoba.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.