Examining the Tissue-Level and Gross Phenotypic Effects of the Connexin43I130T/+ Mutation on the Developing Mouse Skull

Sommer G.E. Jarvis, The University of Western Ontario

Abstract

The purpose of this study was to investigate the effects of reduced Connexin43 function on the developing skull phenotype, osteoblast and chondrocyte proliferation and differentiation, and to determine if a correlation exists between cell processes and gross morphology. Using the Cx43^I130T/+mouse model, skull shape was analyzed using geometric morphometrics and cell proliferation and differentiation were assessed using immunohistochemistry at late embryonic and early post-natal stages. The largest shape changes between Cx43^I130T/+ and wildtype mice were observed in the cranial base and facial skeleton. Changes infacial morphology correspond to reduced osteoblast differentiation. However, no changes in chondrocyte proliferation or differentiation within the cranial base were detected in mutant mice, and thus, alterations to these chondrocyte processes do not explain the profound phenotypic changes observed in the cranial base. This study provides a detailed account of the cellular and phenotypic effects of the Cx43^I130T/+ mutation within the skull.