Doublecortin is 40 kDa microtubule-associated phosphoprotein required for neuronal migration and differentiation in various regions of the developing central nervous system. We have investigated the expression and cellular localization of doublecortin in the developing rat retina using immunocytochemistry and Western blot analysis. The expression of doublecortin was high from embryonic day 18 (...

The establishment of the primitive streak and its derivative germ layers, mesoderm and endoderm, are prerequisite steps in the formation of many tissues. To model these developmental stages in vitro, an ES cell line was established that expresses CD4 from the foxa2 locus in addition to GFP from the brachyury locus. A GFP-Bry(+) population expressing variable levels of CD4-Foxa2 developed upon d...

During mouse gastrulation, cells in the primitive streak undergo epithelial-mesenchymal transformation and the resulting mesenchymal cells migrate out laterally to form mesoderm and definitive endoderm across the entire embryonic cylinder. The mechanisms underlying mesoderm and endoderm specification, migration, and allocation are poorly understood. In this study, we focused on the function of ...

The chemical differences between deep- and shallow-mantle sources of oceanic basalts provide evidence that several distinct components coexist within the Earth's mantle. Most of these components have been identified as recycled in origin. However, the noble-gas signature is still a matter of debate and questions the preservation of primitive regions in the convective mantle. We show that a mode...

Halves of transversely or longitudinally cut primary ectoderm of the pre-primitive streak and the early primitive streak rat embryonic shield developed after 15-30 days in renal homografts into benign teratomas composed of various adult tissues, often in perfect organ-specific associations. No clear difference exists in histological composition of grafted halves of the same embryonic ectoderm. ...

The primitive heart tube is composed of an outer myocardial and an inner endocardial layer that will give rise to the cardiac valves and septa. Specification and differentiation of these two cell layers are among the earliest events in heart development, but the embryonic origins and genetic regulation of early endocardial development remain largely undefined. We have analyzed early endocardial...

Fibroblast growth factor (FGF) signaling has been implicated in the patterning of mesoderm and neural lineages during early vertebrate development. In the mouse, FGF receptor-1 (FGFR1) is expressed in an appropriate spatial and temporal manner to be orchestrating these functions. Mouse embryos homozygous for a mutated Fgfr1 allele (fgfr1(delta tmk)) die early in development, show abnormal growt...

Primitive neuroectodermal tumor (PENETs) is an uncommon malignancy of bone and soft tissue witch rarely occurs in the kidney. In more than 90% of the cases, the tumor cells relieves a balanced translocation (11; 22) (q24; q12). Immunohistochemical staining may be required for diagnosis of PENET. The cells of tumor express CD99, vimentin, NSE, FL1 but do not express Ck, LCA, myogenin, and WT1. W...

The primitive neuroectodermal tumor (PNET) belongs to a group of highly malignant tumors and is composed of small round cells of a neuroectodermal origin. Categorized in the same tumor family as Ewing sarcoma, the PNET is most likely to occur in bones and soft tissues. However, a small number of PNET cases arising in the pelvis have been reported as well. We present three cases of pelvic PNET: ...