Analysis of the expression of microtubule plus-end tracking proteins (+TIPs) during Xenopus laevis embryogenesis.

Microtubules are a component of the cytoskeleton and are important for maintaining cell structure and providing platforms for intracellular transport in diverse cellular processes. Microtubule plus-end tracking proteins (+TIPs), a structurally and functionally diverse group of proteins, are specifically accumulated in the microtubule plus end and regulate dynamic microtubule behavior. We characterized the +TIPs, Clip1, p150(glued), Clasp1, Lis1 and Stim1, in Xenopus laevis and report their expression patterns during embryogenesis in this paper. All the five +TIP genes are maternally expressed and have similar expression patterns during Xenopus embryo development. The expression of +TIPs is localized in the animal hemisphere and ectoderm region at early stages of embryonic development. As development progresses to later stages, the ectodermal expression of +TIPs persists in head and neural tube structures. Clasp1, p150(glued) and Lis1 in particular are specifically expressed in the cranial nerves. Importantly, +TIPs are also expressed in the involuting mesoderm during gastrulation. This is the first study of developmental expression patterns of +TIPs, and our analysis provides insight that could serve as the basis for future research of microtubules in vertebrate development, cell movements during gastrulation and neurogenesis.