부산대학교 도서관

The par (partitioning defective) genes are required for the organization of cellular asymmetry in polarized cells such as C. elegans embryo and mammalian epithelium. We have analyzed the expression patterns of Xenopus par-6 mRNA and protein during early Xenopus embryogenesis. While the Xpar-6 mRNA is expressed both maternally and zygotically at relatively constant levels, its protein gradually increases throughout early Xenopus development, suggesting that translation of Xpar-6 protein is carefully regulated. The maternal Xpar-6 mRNA and protein are localized to the animal hemisphere of the fertilized egg and blastula. At the gastrula stage, the expressions of its zygotic transcripts and protein are restricted to not only the involuting mesoderm, dorsal and ventral, but also ectoderm, neural and epidermal, leading to their later localizations being associated with the mesodermal and ectodermal derivatives including neural tube, neural crest, somites, pronephros, heart and epidermal layer. At the cellular level, Xpar-6 protein appears to be localized to the cell cortex of epithelia. The cellular localizations of Xpar-6 protein within adult organs were also examined. In all organs studied, the specific staining is associated with epithelial cells of either a columnar or a cuboidal type that are organized in tubular structures. The smooth muscle cells also show positive staining for Xpar-6 protein.