FishFace: interactive atlas of zebrafish craniofacial development at cellular resolution

Abstract

BackgroundThe vertebrate craniofacial skeleton may exhibit anatomical complexity and diversity, but its genesis and evolution can be understood through careful dissection of developmental programs at cellular resolution. Resources are lacking that include introductory overviews of skeletal anatomy coupled with descriptions of craniofacial development at cellular resolution. In addition to providing analytical guidelines for other studies, such an atlas would suggest cellular mechanisms underlying development.DescriptionWe present the Fish Face Atlas, an online, 3D-interactive atlas of craniofacial development in the zebrafish Danio rerio. Alizarin red-stained skulls scanned by fluorescent optical projection tomography and segmented into individual elements provide a resource for understanding the 3D structure of the zebrafish craniofacial skeleton. These data provide the user an anatomical entry point to confocal images of Alizarin red-stained zebrafish with transgenically-labelled pharyngeal arch ectomesenchyme, chondrocytes, and osteoblasts, which illustrate the appearance, morphogenesis, and growth of the mandibular and hyoid cartilages and bones, as viewed in live, anesthetized zebrafish during embryonic and larval development. Confocal image stacks at high magnification during the same stages provide cellular detail and suggest developmental and evolutionary hypotheses.ConclusionThe FishFace Atlas is a novel learning tool for understanding craniofacial skeletal development, and can serve as a reference for a variety of studies, including comparative and mutational analyses.

Ligament versus bone cell identity in the zebrafish hyoid skeleton is regulated by mef2ca

“…However, we detect no evidence of these, which would be observable in our time-lapse recordings with fli1a: NLSmCherry , ruling out these hypotheses. Another alternative hypothesis regarding the identity of the ectopic bone is that it is a precocious interopercle, a bone that forms anterior to the opercle later in development (Eames et al, 2013). However, when we examined the interopercle in relation to the operculohyoid ligament in wild types we observed that this bone initiates near the interhyal cartilage, far from the opercle, whereas the ectopic bone in mef2ca b1086 mutants develops adjacent to the opercle.…”

“…See supplementary Materials and Methods for these and all other primer sequences. The following transgenic lines have been previously described: Tg(sp7:EGFP) b1212 , sox9a:EGFP zc81Tg (Eames et al, 2013), Tg(alx4a:DsRed2)pd52 (Nachtrab et al, 2013). To generate Tg(fli1a: NLSmCherry)b1252, the fli1a ectomesenchyme enhancer ( p5E-fli1a-Fhsp70I) (Das and Crump, 2012) was recombined upstream of NLS-mCherry using the Tol2 kit (Kwan et al, 2007).…”

An FDA-Approved Drug Screen for Compounds Influencing Craniofacial Skeletal Development and Craniosynostosis

“…Since osteoblasts and osteoclasts are also located throughout this cartilage around the time points that we analysed [Eames et al, 2013;Sharif et al, 2014; Mork and Crump, 2015], it is conceivable that our screen could also identify compounds that influence these cell types, although we note that no mineralised bone is present at these stages. Indeed, our temporal analyses of leflunomide treatment suggested biphasic effects in repressing early NCSC induction and later independent effects on cartilage remodelling.…”

“…Once formed, these cartilage elements are remodelled through convergent extension cell movements of chondrocytes, enzymatic regulation of extracellular matrix glycosaminoglycans, and cellular hypertrophy. Both osteoblasts and osteoclasts localise throughout the zebrafish jaw at these stages or shortly afterwards [Eames et al, 2013;Sharif et al, 2014;Mork and Crump, 2015]. Anatomically, this manifests as a progressive reduction in the angle between the ceratohyoids and the other branchial arch cartilages between 3-5 dpf.…”

Danio rerio: the Janus of the bone from embryo to scale

“…The use of the mutants is a powerful tool to study the role of the genes involved in the development of the vertebrate skeleton. Several mutants isolated from big screens have shown high correspondence with human patients affected by bone disusing osterix/sp7 promoter such as Tg(sp7:EGFP)b1212 (21), medaka osx-mCherry (22) and Tg(Ola.Sp7:NLS-GFP)zf132 (23) have been made to study the timing of the osteoblast differentiation and the regulation pathways of the embryonic osteogenesis as well as craniofacial bone mapping (24). Osteocalcin, or bone Gla protein, is a small protein secreted by osteoblasts and found in bone extracellular matrix as hydroxyapatite-binding protein or in the blood as circulating form implicated in the regulation of glucose homeostasis.…”