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One mechanism for the specification of cell types during embryonic development is the cytoplasmic localization of determinants in the egg into certain blastomeres. Primordial germ cell (PGC) development in many organisms is characterized by the inheritance of germ plasm, a cytologically distinct assembly of mitochondria and electron-dense germinal granules.(More)
Xdazl is an RNA component of Xenopus germ plasm and encodes an RNA-binding protein that can act as a functional homologue of Drosophila boule. boule is required for entry into meiotic cell division during fly spermatogenesis. Both Xdazl and boule are related to the human DAZ and DAZL, and murine Dazl genes, which are also involved in gamete differentiation.(More)
VegT is a T-box transcription factor whose mRNA is synthesized during oogenesis and localized in the vegetal hemisphere of the egg and early embryo. We show that maternally expressed VegT controls the pattern of primary germ layer specification in Xenopus embryos. Reduction of the maternal store completely alters the fates of different regions of the(More)
We have identified a localized RNA component of Xenopus germ plasm. This RNA, Xdazl (Xenopus DAZ-like), encodes a protein homologous to human DAZ (Deleted in Azoospermia), vertebrate DAZL and Drosophila Boule proteins. Human males deficient in DAZ have few or no sperm and boule mutant flies exhibit complete azoospermia and male sterility. Xdazl RNA was(More)
DEADSouth was selected in a screen for localized RNAs in Xenopus oocytes. In situ hybridization analysis shows that DEADSouth localizes to the vegetal cortex via the mitochondrial cloud early in oogenesis and segregates with germ plasm during early embryogenesis. These results lend further support for the general concept that the role of the early RNA(More)
Early in the development of animal embryos, superficial cells of the blastula form a distinct lineage and adopt an epithelial morphology. In different animals, the fate of these primary superficial epithelial (PSE) cells varies, and it is unclear whether pathways governing segregation of blastomeres into the PSE lineage are conserved. Mutations in the gene(More)
In the early Xenopus embryo, the dorsal axis is specified by a Wnt signal transduction pathway, involving the movement of beta-catenin into dorsal cell nuclei and its functional association with the LEF-type transcription factor XTcf3. The subsequent function of XTcf3 is uncertain. Overexpression data has suggested that it can be both an activator and(More)
The Wingless (Wg)/Wnt signal transduction pathway regulates many developmental processes through a complex of Armadillo(Arm)/beta-catenin and the HMG-box transcription factors of the Tcf family. We report the identification of a new component, Pygopus (Pygo), that plays an essential role in the Wg/Wnt signal transduction pathway. We show that Wg signaling(More)
Establishment of the left-right axis is essential for normal organ morphogenesis and function. Ca(2+) signaling and cilia function in the zebrafish Kuppfer's Vesicle (KV) have been implicated in laterality. Here we describe an endogenous Ca(2+) release event in the region of the KV precursors (dorsal forerunner cells, DFCs), prior to KV and cilia formation.(More)
The ability to manipulate gene expression in Xenopus oocytes and then generate fertilized embryos by transfer into host females has made it possible to rapidly characterize maternal signaling pathways in vertebrate development. Maternal mRNAs in particular can be efficiently depleted using antisense deoxyoligonucleotides (oligos), mediated by endogenous(More)