Nkx2-5 and Sarcospan genetically interact in the development of the muscular ventricular septum of the heart.

The muscular ventricular septum separates the flow of oxygenated and de-oxygenated blood in air-breathing vertebrates. Defects within it, termed muscular ventricular septal defects (VSDs), are common, yet less is known about how they arise than rarer heart defects. Mutations of the cardiac transcription factor NKX2-5 cause cardiac malformations, including muscular VSDs.

Complex trait analysis of ventricular septal defects caused by Nkx2-5 mutation.

Background: The occurrence of a congenital heart defect has long been thought to have a multifactorial basis, but the evidence is indirect. Complex trait analysis could provide a more nuanced understanding of congenital heart disease.

Methods And Results: We assessed the role of genetic and environmental factors on the incidence of ventricular septal defects (VSDs) caused by a heterozygous Nkx2-5 knockout mutation.

Heterogeneity of genetic modifiers ensures normal cardiac development.

Background: Mutations of the transcription factor Nkx2-5 cause pleiotropic heart defects with incomplete penetrance. This variability suggests that additional factors can affect or prevent the mutant phenotype. We assess here the role of genetic modifiers and their interactions.

Applying genomics to the avian inner ear: development of subtractive cDNA resources for exploring sensory function and hair cell regeneration.

We applied a micro-cDNA-based subtraction method to identify genes expressed in the regenerating sensory epithelia (SE) of the chicken inner ear. Sensory hair cells in the avian utricle SE are in a constant state of turnover, where dying hair cells are replaced by new ones derived from supporting cells. In contrast, hair cells in the cochlea remain quiescent unless damaged.

Gene expression in pharyngeal arch 1 during human embryonic development.

Craniofacial abnormalities are one of the most common birth defects in humans, but little is known about the human genes that control these important developmental processes. To identify relevant genes, we analyzed transcription profiles of human pharyngeal arch 1 (PA1), a conserved embryonic structure that develops into the palate and jaw. Using microdissected, normal human craniofacial structures, we constructed 12 SAGE (serial analysis of gene expression) libraries and sequenced 606 532 tags.