This model, called a conditional knockout, should help scientists unlock the mysteries of normal as well as abnormal development of these systems, opening the door to a better understanding of everything from heart defects in children to some cancers to spina bifida.

"Now we can say, ‛OK, if this gene is expressed everywhere and is in all these different tissues, can we generate a mouse that will now let us look at its role in just the heart, or just in the skin, or just during ear development and so on?'" said Dr. Simon J. Conway, developmental biologist, geneticist and principal author on the research published in a special February issue of Genesis: The Journal of Genetics and Development. The journal features 43 papers documenting the development of a variety of these conditional knockouts - rather than waiting for research results from the use of those mice - to facilitate research and collaboration.

Dr. Conway's laboratory, which focuses on heart development and congenital defects, will use the new animal model to explore the role of PAX-3, a gene that regulates other genes, in the development of the heart muscle itself as well as the two big vessels that exit the heart. Children born with a mutation of this gene are often called 'blue babies' because they have only one big vessel coming off their heart instead of a separate aorta, the major vessel that sends blood out to the body, and pulmonary trunk, which returns oxygen-poor blood to the lungs. While the anatomical problem usually can be corrected surgically, some of these children also have the potentially more lethal problem of a poorly beating heart.

PAX-3 actually has many roles in both formation and function throughout the body, and is involved in not only the heart
'"/>

Contact: Toni Baker
tbaker@mail.mcg.edu
706-721-4421
Medical College of Georgia
13-Feb-2002