Inactivation of the Huntington's disease gene (Hdh) impairs anterior streak formation and early patterning of the mouse embryo.

Background: Huntingtin, the HD gene encoded protein mutated by polyglutamine expansion in Huntington's disease, is required in extraembryonic tissues for proper gastrulation, implicating its activities in nutrition or patterning of the developing embryo. To test these possibilities, we have used whole mount in situ hybridization to examine embryonic patterning and morphogenesis in homozygous Hdh(ex4/5) huntingtin deficient embryos.

Results: In the absence of huntingtin, expression of nutritive genes appears normal but E7.

Magic roundabout, a tumor endothelial marker: expression and signaling.

Molecular signals that guide blood vessels to specific paths are not fully deciphered, but are thought to be similar to signals that mediate neuronal guidance. These cues are not only critical for normal blood vessel development, but may also play a major role in tumor angiogenesis. In this study, we have demonstrated the tumor endothelial specific expression of a Robo family member, magic roundabout (MRB), functionally characterized its role in endothelial cell migration and defined a signaling pathway that might mediate this function.

A neural survival factor is a candidate oncogene in breast cancer.

Using serial analysis of gene expression (SAGE), we identified a SAGE tag that was present only in invasive breast carcinomas and their lymph node metastases. The transcript corresponding to this SAGE tag, dermcidin (DCD), encodes a secreted protein normally expressed only in the pons of the brain and sweat glands. Array comparative genomic hybridization, fluorescence in situ hybridization, and immunohistochemical analyses determined that DCD is overexpressed in approximately 10% of invasive breast carcinomas; in some cases its overexpression is coupled with a focal copy number gain of its locus at 12q13.

The epithelium-specific ETS protein EHF/ESE-3 is a context-dependent transcriptional repressor downstream of MAPK signaling cascades.

Exon trapping and cDNA selection procedures were used to search for novel genes at human chromosome 11p13, a region previously associated with loss of heterozygosity in epithelial carcinomas. Using these approaches, we found the ESE-2 and ESE-3 genes, coding for ETS domain-containing transcription factors. These genes lie in close proximity to the catalase gene within a approximately 200-kilobase genomic interval.

Retinal degeneration but not obesity is observed in null mutants of the tubby-like protein 1 gene.

The tub gene is a member of a small, well conserved neuronal gene family of unknown function. Mutations within this gene lead to early-onset blindness and deafness, as well as late-onset obesity and insulin resistance. To test the hypothesis that mutations within other members of this gene family would lead to similar phenotypes as observed in tubby mice, and hence have similar functional properties, we have generated null mutants of the tubby-like protein ( Tulp ) 1 gene by homologous recombination.