Differential Expression of WNT3 and WNT9B in the Developing Primary Palate of Normal and Cleft Embryonic (CL/Fr) Mice

Abstract

Cleft lip and palate (CLP) is a common craniofacial anomaly that can produce respiratory, swallowing, and speech problems. Exact mechanisms producing CLP are currently unresolved, but CLP is known to result from an improper fusion of the primary palate. The CL/Fr strain of mice was used to study CLP, as CL/Fr mice have a 35% chance of developing CLP. Two genes, Wnt3 and Wnt9b, have been indicated to be involved in CLP. Research performed by Brennan Takagi has shown that Wnt9b expression is disrupted in E11.5 CL/Fr tissue. This study continues Takagi’s work by examining Wnt3 and Wnt9b expression in E10.5-E11.0 CL/Fr embryos using qPCR. At E10.5, expression of both Wnt3 and Wnt9b is expected to be reduced in CL/Fr embryos. Results: Expression of Wnt3 and Wnt9b in CL/Fr embryos was relatively equal at E10.5. Wnt3 and Wnt9b expression increased from E10.5 to E11.0, but the increase in Wnt9b expression was greater than the increase in Wnt3 expression. A large degree of standard deviation was present in average Wnt3 and Wnt9b expression in E10.5-E11.0 CL/Fr embryos, but not in E10.5 3H1 embryos, and may indicate varying amounts of CL/Fr. Conclusion: High variability in Wnt3 and Wnt9b expression in E10.5 CL/Fr embryos made it difficult to determine if E10.5 CL/Fr E10.5 embryos showed reduced expression of Wnt3 and Wnt9b. However, Wnt3 expression and Wnt9b expression do appear to increase at unequal rates in CL/Fr embryos from E10.5 to E11.0, confirming current research into normal craniofacial morphogenesis and providing a base of comparison for future research into CL/Fr mice and cleft palate.