The receptor tyrosine kinase Kit is known as one of the phosphorylating enzymes that transmit extracellular signals into the cell and regulates various properties of the cell. It is known that Kit has an important role in the proliferation and differentiation of stem cells necessary for the development and regeneration of tissues and organs.However, the role of Kit in the most abundant expression in the brain has not been clarified so far.
For the first time in the world, Lecturer Hitomi Aoki of Gifu University Graduate School of Medicine discovered that Kit plays an important role in brain formation.In this study, we observed the growth of genetically engineered mice that lost the function of the Kit gene in the cranial nerve region.In all of these mice, brain growth did not progress and all died during the fetal period.Furthermore, examination of neural stem cells revealed that their proliferation was abnormal.
No abnormality was found in the brains of mutant mice that had already lost the function of Kit at the stage of fertilized eggs.In the presentation, it is hypothesized that if there is an abnormality in the Kit at the stage of fertilized egg, the gene that substitutes for the function of the Kit will be expressed instead, and the growth of the brain will be induced.In the case of the genetically engineered mice used in this study, the function of the Kit suddenly disappeared around 8.5 days after fertilization when the formation of the brain started, so the neural stem cells that depended on the Kit signal died without proliferating, and the brain. It is thought that the growth of the mouse will not progress.
In addition to Kit, there are many genes whose expression is observed but whose function is not clear.By analogy with the results of this study, if these genes also lose their function at the fertilized egg stage, there is a possibility that abnormalities will not be observed due to the expression of another alternative gene.By confirming this prediction with other genes in the future, new functions may be discovered in many genes.
Paper information:[JCI insight] Induced haploinsufficiency of Kit receptor tyrosine kinase impairs brain development
