Cleft palate is a common major birth defect for which currently known causes account for less than 30% of pathology in humans. In this study, we carried out mutagenesis screening in mice to identify new regulators of palatogenesis. Through genetic linkage mapping and whole-exome sequencing, we identified a loss-of-function mutation in the Golgb1 gene that co-segregated with cleft palate in a new mutant mouse line. Golgb1 is a ubiquitously expressed large coiled-coil protein, also known as giantin, that is localized at the Golgi membrane. Using CRISPR/Cas9-mediated genome editing, we generated and analyzed developmental defects in mice carrying additional Golgb1 loss-of-function mutations, which supported a crucial requirement for Golgb1 in palate development. Through maxillary explant culture assays, we demonstrate that the Golgb1 mutant embryos have intrinsic defects in palatal shelf elevation. Just prior to the developmental stage of palatal shelf elevation in wild-type littermates, Golgb1 mutant embryos exhibit increased cell density, reduced hyaluronan accumulation and impaired protein glycosylation in the palatal mesenchyme. Together, these results demonstrate that, although it is a ubiquitously expressed Golgi-associated protein, Golgb1 has specific functions in protein glycosylation and tissue morphogenesis.
The authors declare no competing or financial interests.
Y.L. conceived the study; Y.L. designed the experiments with input from R.J.; Y.L. performed most of the experiments and N.Z., H.L. and J.X. performed some experiments under instructions of Y.L.; Y.L., N.Z. R.J. analyzed results; Y.L. wrote the manuscript with input from R.J. and N.Z.; all authors read and commented on it
This work was supported by a Cincinnati Children's Hospital Medical Center Trustee Award (to Y.L.); and by grants from the National Institutes of Health National Institute of Dental and Craniofacial Research [R03DE023864 to Y.L., R01DE013681 to R.J.]. Deposited in PMC for release after 12 months.
Supplementary information available online at http://dev.biologists.org/lookup/doi/10.1242/dev.134577.supplemental
- Received January 8, 2016.
- Accepted May 9, 2016.