"The neural tube is the beginning of the brain and spinal cord, " said the study's lead investigator Lee Niswander, professor of pediatrics at the CU School of Medicine. "A defect in the mLin41 gene doesn't allow the tube to close because not enough neural progenitor cells are being made."

　　Niswander and the paper's first author, Jianfu Chen, made their findings while studying neural stem cells in mice. They said the cells use distinct self-renewal programs to meet the demand of tissue growth and repair during different stages of embryonic development. The molecular mechanisms that control these programs remain largely unknown.

　　The researchers discovered that the gene mLin41 in mice controls the extent of neural stem cell proliferation during the process of neural closure but not at the later stage of brain development. According to Chen, mLin41 works with small RNAs and RNA regulators that have never been investigated before in connection with neural tube formation.

　　"Our work opens up a whole other pathway toward understanding neural tube defects," Niswander said. "It's a new and significant piece of the puzzle behind understanding how this happens."