Renal morphology in connexin43 knockout mice.

Connexins (Cx) are a family of proteins that constitute the intercellular membrane channels of gap junctions. These junctions permit intercellular movement of ions and other molecules between cells, a property vital to organogenesis. Cx43 is a member of the family of channel-forming proteins that are essential for cell-cell communication of developmental signals. Studies demonstrate that Cx43 is observed in mesenchymal cells of 12-day gestation mouse kidney, a crucial period of renal development. In order to study the significance of Cx43 on renal developmental morphology, we evaluated the kidneys of embryos lacking the gene encoding for Cx43. Polymerase chain reaction (PCR) from tail specimens identified wild-type (WT), heterozygote (HT) and knockout (KO) progeny. In situ RT-PCR displayed abundant Cx43 staining in glomeruli, vasculature, and tubules in kidneys obtained from WT progeny. In contrast, Cx43 expression was completely absent in kidneys isolated from the KO. Renal histology in all three groups displayed no significant differences. Renal size was similar and there was no evidence of dysplasia or cyst formation in the KO. Our results indicate that absence of Cx43, heretofore considered essential for renal development, does not affect early renal morphological development.