Analysis of Xenopus laevis claudin (Xcla) Tight Junction Genes in Development

Abstract

Eight Xenopus laevis claudin genes, Xcla1, Xcla4B, Xcla5, Xcla6, Xcla12, Xcla16, Xcla18 and Xcla19, were cloned and sequenced. Their normal mRNA expression was determined from cleavage stage to tadpole stage by whole mount in situ hybridization. The protein expression of Xcla5 was detected at the neural stage by whole mount immunostaining. Overexpression of Xcla5 by injection of synthetic mRNA into embryos caused morphological defects similar to those in embryos exposed to Bisphenol A (BPA). Altered patterns of claudin gene expression in the presence of BPA can be correlated with these developmental defects. The results suggest that claudins may play an important role in neural crest cell migration, epithelial-mesenchymal transition and ultimately organogenesis during embryonic development.