Functional analysis of SPECC1L in craniofacial development and oblique facial cleft pathogenesis.

Plast Reconstr Surg
Authors
Keywords
Abstract

BACKGROUND: Oblique facial clefts, also known as Tessier clefts, are severe orofacial clefts, the genetic basis of which is poorly understood. Human genetics studies revealed that disruption in SPECC1L resulted in oblique facial clefts, demonstrating that oblique facial cleft malformation has a genetic basis. An important step toward innovation in treatment of oblique facial clefts would be improved understanding of its genetic pathogenesis. The authors exploit the zebrafish model to elucidate the function of SPECC1L by studying its homolog, specc1lb.

METHODS: Gene and protein expression analysis was carried out by reverse-transcriptase polymerase chain reaction and immunohistochemistry staining. Morpholino knockdown, mRNA rescue, lineage tracing and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assays were performed for functional analysis.

RESULTS: Expression of specc1lb was detected in epithelia juxtaposed to chondrocytes. Knockdown of specc1lb resulted in bilateral clefts between median and lateral elements of the ethmoid plate, structures analogous to the frontonasal process and the paired maxillary processes. Lineage tracing analysis revealed that cranial neural crest cells contributing to the frontonasal prominence failed to integrate with the maxillary prominence populations. Cells contributing to lower jaw structures were able to migrate to their destined pharyngeal segment but failed to converge to form mandibular elements.

CONCLUSIONS: These results demonstrate that specc1lb is required for integration of frontonasal and maxillary elements and convergence of mandibular prominences. The authors confirm the role of SPECC1L in orofacial cleft pathogenesis in the first animal model of Tessier cleft, providing morphogenetic insight into the mechanisms of normal craniofacial development and oblique facial cleft pathogenesis.

Year of Publication
2014
Journal
Plast Reconstr Surg
Volume
134
Issue
4
Pages
748-59
Date Published
2014 Oct
ISSN
1529-4242
URL
DOI
10.1097/PRS.0000000000000517
PubMed ID
25357034
PubMed Central ID
PMC4430087
Links
Grant list
P01 GM061354 / GM / NIGMS NIH HHS / United States
U01 DE024443 / DE / NIDCR NIH HHS / United States
P01GM061354 / GM / NIGMS NIH HHS / United States