Strain-Dependent Gene Expression during Mouse Embryonic Palate Development

The effect of strain background on gene function in growth and development has been well documented. However, it has not been extensively reported whether the strain background affects the gene expression pattern. Here, we found that the expression of homeobox gene Meox-2 and FGF receptor 1 gene Fgfr1 during mouse palate development is strain-dependent. On the C57B6 inbred background, Meox-2 is expressed in the palatal outgrowth on Embryonic Day 11.5 (E11.5); the expression shifts posteriorly and is restricted to the back of palate on E14.5. On the Swiss Webster outbred background, Meox-2 expression covers both anterior and posterior regions with the same intensity from E12.5 to E14.5. On the Black Swiss background, Meox-2 expression also covers the entire palate A-P axis, but is much weaker in the anterior region on E14.5. Fgfr1 also displays distinct expression patterns in the palatal outgrowth on E11.5 in these three strains. On the Black Swiss outbred background, the expression is restricted to the anterior palatal outgrowth. In marked contrast, the expression in the Swiss Webster outbred strain is located exclusively in the posterior palate outgrowth on E11.5, whereas in the C57B6 inbred strain, the expression is undetectable in the palatal outgrowth on E11.5.