We present evidence that hedgehog (hh) protein secreted by posterior compartment cells plays a key role in patterning the posterior portion of the anterior compartment in adult abdominal segments. Loss of function of hh in the hh(ts2) mutant causes the loss of posterior tergite characteristics in the anterior compartment, whereas ectopic expression driven by hs-hh or the gain-of-function allele...

The Abdominal-B (Abd-B) gene, a member of the bithorax complex (BX-C), specifies the identities of parasegments (PS) 10-14 in Drosophila. Abd-B codes for two structurally related homeodomain proteins, ABD-B m and ABD-B r, that are expressed in PS10-13 and PS14-15, respectively. Although ABD-B m and r proteins have distinct developmental functions, ectopic expression of either protein during emb...

Acute myeloid leukemia (AML) as a distortion of blood cells involves the differentiation of hematopoietic stem cells. Several studies established the irregular overexpression of specific genes is a common finding in patients with AML. The ectopic viral integration site-1 (EVI1) gene is a proto-oncogene subject to alternative splicing, and encodes a zinc-finger protein that acts as a tr...

Forkhead box L1 (FOXL1), which is considered a novel candidate tumor suppressor, inhibits proliferation and invasion in certain types of cancer. However, the regulation and function of FOXL1 in osteosarcoma remains unclear. The expression of FOXL1 gene in osteosarcoma tissues and cell lines was examined using RT-PCR, immunohistochemistry and western blot analysis. pcDNA-FOXL1 carrying full-leng...

It has been reported that members of the fibroblast growth factor (FGF) family can induce additional limb formation in the flank of chick embryos. The phenotype of the ectopic limb depends on the somite level at which it forms: limbs in the anterior flank resemble wings, whereas those in the posterior flank resemble legs. Ectopic limbs located in the mid-flank appear chimeric, possessing charac...

Understanding the role of morphogen in activating its target genes, otherwise epigenetically repressed, during change in cell fate specification is a very fascinating yet relatively unexplored domain. Our in vivo loss-of-function genetic analyses reveal that specifically during ectopic eye formation, the morphogen Decapentaplegic (Dpp), in conjunction with the canonical signaling responsible fo...

Members of the Achaete-scute family of basic helix-loop-helix transcription factors are involved in cell fate specification in vertebrates and invertebrates. We have isolated and characterized a cnidarian achaete-scute homolog, CnASH, from Hydra vulgaris, a representative of an evolutionarily ancient branch of metazoans. There is a single achaete-scute gene in Hydra, and the bHLH domain of the ...

During forebrain development, Mash1 directs gamma-aminobutyric acid (GABA)ergic neuron differentiation ventrally in the ganglionic eminences. Repression of Mash1 in the cortex is necessary to prevent the formation of GABAergic interneurons. Negative regulation of Mash1 has been attributed to members of the Neurogenin family; the genetic ablation of Neurogenin2 (Ngn2) leads to the derepression o...

During vertebrate limb development, the ectoderm directs the dorsoventral patterning of the underlying mesoderm. To define the molecular events involved in this process, we have analyzed the function of WNT7a, a secreted factor expressed in the dorsal ectoderm, and LMX1, a LIM homeodomain transcription factor expressed in the dorsal mesenchyme. Ectopic expression of Wnt7a is sufficient to induc...

The formation of localised signalling centres is essential for patterning of a number of tissues during development. Previous work has revealed that a distinct population of boundary cells forms at the interface of segments in the vertebrate hindbrain, but the role of these cells is not known. We have investigated the function of the Wnt1 signalling molecule that is expressed by boundary and ro...