FAC1 EXPRESSION AND LOCALIZATION IN MOTOR-NEURONS OF DEVELOPING, ADULT, AND AMYOTROPHIC-LATERAL-SCLEROSIS SPINAL-CORD

In this study we report the localization and expression of FAC1 protei n in developing, normal adult and amyotrophic lateral sclerosis (ALS) lumbar spinal cord. High levels of FAC1 protein were detected in cells throughout all areas (gray and white matter) of the developing lumbar spinal cord. FAC1 protein was localized predominately in nuclei and t he cell body of motor neurons during early stages of spinal cord devel opment. In contrast, low levels of FAC1 protein were observed in the a dult lumbar spinal cord, localized only in the cell body of large alph a motor neurons found in lamina IX. Interestingly, FAC1 protein expres sion was elevated in surviving motor neurons of ALS spinal cord compar ed to the controls and was located both in the nucleus and throughout the cytoplasm of motor neurons. FAC1 protein was also observed in whit e matter cells and fibers in ALS spinal cord. In support of the immuno cytochemical results, in situ hybridization studies demonstrated that FAC1 mRNA is also elevated in ALS spinal cord motor neurons. These dat a describe the developmental regulation of FAC1 protein in the spinal cord by immunocytochemical techniques and provide evidence that this p rotein is reexpressed in ALS motor neurons. (C) 1997 Academic Press.