The endoderm contributes cells to the gut, and participates in the induction and patterning of the vertebrate head and heart. The mechanisms controlling the formation of endoderm are poorly understood. Commitment of endoderm cells occurs at the onset of gastrulation and requires cell interactions; studies in vitro have implicated transforming growth factor Beta (TGF-beta)-related molecules in t...

The Wnts are a family of secreted glycoproteins involved in cell-cell signalling and pattern formation during development, although the extent to which various Wnts are functionally equivalent remains unclear. We have cloned zebrafish (Danio rerio) wnt4, characterized its expression, and compared its activity relative to other Wnts. The wnt4 transcript is first detected early in somitogenesis, ...

 Isolated from corn lily Veratrum californicum.  Ingestion of the corn lily (Veratrum californicum) by pregnant sheep caused the birth of lambs with cyclopia. The Veratrum alkaloid cyclopamine was identified as the causative agent. It is very expensive commercially (~$10/mg), No total synthesis is available in literature after 50 year of its isolation. Inhibition of Hh signaling provides a ro...

A number of designations for human body structures derive from classical mythology. These eponyms in the vocabulary of macroscopic anatomy and teratology (e.g., Achilles tendon, Ammon’s horn, cyclopia and sirenomelia) have not been systematically investigated until now. This paper therefore provides an overview of this fringe component of anatomical vocabulary, analyzes the medical history of s...

One of the most perplexing questions in clinical genetics is why patients with identical gene mutations oftentimes exhibit radically different clinical features. This inconsistency between genotype and phenotype is illustrated in the malformation spectrum of holoprosencephaly (HPE). Family members carrying identical mutations in sonic hedgehog (SHH) can exhibit a variety of facial features rang...

The main goal was to standardize the FETAX (Frog Embryos Teratogenesis Assay: Xenopus) test. Since lithium ions are known to be teratogenic for embryos of many organisms, they were prefferred for our first standardization assay. Xenopus laevis embryos were exposed to lithium chloride (from 2x10–4 to 6 x 10–3 M concentrations) for 96 hours at 2–4 cell stages of development. Exposure to lower LiC...