Abstract
and
are important for palate development across vertebrates. In zebrafish, we found that
regulates the expression of
We detailed overlapping
and
expression in mouse orofacial epithelium. In zebrafish,
and
share expression in periderm, frontonasal ectoderm and oral epithelium. Genetic disruption of
and
in zebrafish resulted in cleft of the anterior neurocranium. The
mutant also developed cleft of the mouth opening. Lineage tracing of cranial neural crest cells revealed that the cleft resulted not from migration defect, but from impaired chondrogenesis. Analysis of aberrant cells within the cleft revealed expression of
,
and
, and these cells were adjacent to
and
cells. Breeding of mouse
;
;
compound mutants suggested genetic interaction, as the triple homozygote and the
;
double homozygote were not observed. Further,
heterozygosity reduced
cleft severity. These studies highlight the complementary analysis of
and
in mouse and zebrafish, and identify a unique aberrant cell population in zebrafish expressing
,
and
Future work characterizing this cell population will yield additional insight into cleft pathogenesis.