Yang Chai's study of embryonic cells that shape craniofacial structures gained new support from a three-year, $225,000 March of Dimes Birth Defects Foundation grant "This funding source has infrequently supported craniofacial research so receiving this grant is a real accomplishment," said Charles Shuler, director of the school's Center for Craniofacial Molecular Biology.

How embryonic cells develop and multiply as they travel from the cranial neural crest (CNC) of a developing embryo is critical. It can determine whether a newborn has normal craniofacial features or is one who suffers from cleft lip and/or palate. According to figures from the March of Dimes Perinatal Data Center, 2000, an estimated one out of every 930 U.S. children are born each year with oral clefts-one of the most common birth defects in the United States.

"Growth and transcriptional factors are critical regulators for the fate of cranial neural crest cells," explained Chai. TGF-beta, a transforming growth factor, and Msx1, a transcription factor, are the focus of attention for Chai and colleagues. It is known that TGF-beta can negatively affect the expression of Msx1, a factor critical for proliferation and differentiation of cells into phenotypes, such as teeth, cartilage and bone. Just what this means for the future of CNC cells is what Chai hopes to learn.

He and colleagues are looking at the signaling that occurs through a string of molecules between TGF-beta2 and Msx1. They want to see if the molecules that carry the signal are specific for regulating tooth development, and, if so, to determine the significance and consequences.

"Ultimately, this study will contribute to our understanding how the signaling pathway between TGF-beta and Msx1 regulates the fate of CNC during normal craniofacial development and how pathway disruption can lead to craniofacial malformations," Chai said. His colleagues in this study include Jun Han, a USC graduate student in craniofacial molecular biology, and Yoshihiro Ito, research associate.