Histone deacetylase inhibitor, trichostatin A, affects gene expression patterns during morphogenesis of chicken limb buds in vivo.

Acetylation is one of the key chromatin modifications that control gene transcription during embryonic development and tumorigenesis. The types of genes sensitive to such modifications in vivo are not known to date. We investigated the expression of a number of genes involved in embryonic development after treatment with trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, in the limbs of chicken embryos.

Avian somitogenesis: translating time and space into pattern.

Vertebrates have a metameric bodyplan that is based on the presence of paired somites. Somites develop from the segmental plate in a cranio-caudal sequence. At the same time, new material is added from Hensen's node, the primitive streak and the tailbud.

Revisiting vimentin expression in early chick development.

To identify somite-specific antigens exhibiting novel expression patterns in the developing chick embryo, epithelial somites were isolated and used for intrasplenic immunization. Immunohistochemical screening of chick embryos of various stages focussed our attention on a monoclonal antibody, Som5H5, which stained somitic derivatives, spinal nerves, and neural tubes as well as the costameres of adult skeletal muscle. Western blot and mass spectrometric analysis revealed the Som5H5 antigen to be vimentin, the distribution of which has been well characterized before.

Morphological left-right asymmetry of Hensen's node precedes the asymmetric expression of Shh and Fgf8 in the chick embryo.

Hensen's node and the rostral part of the primitive streak of chick embryos at HH-stage 4-7 were investigated using scanning electron microscopy, a series of semithin sections, and whole-mount in situ hybridization. An asymmetric expression of Shh and Fgf8 was first found at HH-stage 5. The asymmetric expression of both laterality genes is preceded by an asymmetric morphology of the avian organizer.