Project description:Deficiency of the human short stature homeobox-containing gene (SHOX) has been identified in several disorders characterized by reduced height and skeletal anomalies such as Turner, Leri-Weill and Langer syndrome as well as idiopathic short stature. Although highly conserved in vertebrates, rodents lack a SHOX orthologue. Here, we compared gene expression profiles of wildtype and SHOX transgenic mouse limbs using microarray experiments to identify SHOX target genes in the developing limb. Limbs of E12.5 mouse embryos were dissected, fore- and hindlimbs were pooled and genotyped for RNA extraction. RNA from 2 to 4 littermates was pooled per genotype (Wildtype and SHOX transgene) and compared. In total, 2 microarray hybridization experiments were performed using RNA from 2 biological replicate samples for each genotype.
Project description:Deficiency of the human short stature homeobox-containing gene (SHOX) has been identified in several disorders characterized by reduced height and skeletal anomalies such as Turner, Leri-Weill and Langer syndrome as well as idiopathic short stature. Although highly conserved in vertebrates, rodents lack a SHOX orthologue. Here, we compared gene expression profiles of wildtype and SHOX transgenic mouse limbs using microarray experiments to identify SHOX target genes in the developing limb.
Project description:The SHOX2 transcription factor is required during mouse embryonic development for the formation of the proximal elements of limbs, the humerus and femur. The Shox2 gene is flanked by an extensive gene desert spanning over 500 kilobases (kb) that contains many evolutionarily conserved elements with predicted cis-regulatory activities. However, the transcriptional enhancer potential of the vast majority of these regions have not yet been assessed. Therefore, we have generated a map of the Shox2 regulatory landscape during limb development using chromosome conformation capture techniques (4C-Seq). We report that at least five enhancers, distributed over more than 500 kb interact with the Shox2 gene and control its expression in developing proximal limbs, as confirmed by transgenic mouse assays. Furthermore, by using two of the identified enhancer candidates as 4C-seq viewpoints, we also find evidence that three of these putative enhancers interact with each other as well as the Shox2 gene, perhaps forming a cooperative regulatory complex. We expect this study to provide insight into the regulation of the human SHOX gene, a closely-related homolog of Shox2, that is similarly flanked by a large gene desert. Notably, deletions within the gene desert downstream of human SHOX are implicated as a major cause of the limb deformities characteristic of Léri-Weill dyschondrosteosis.
