GLIAL-CELL CULTURES FROM BRAINS OF CARBONIC-ANHYDRASE II-DEFICIENT MUTANT MICE - DELAY IN OLIGODENDROCYTE MATURATION

Carbonic anhydrase II (CAII) is a multifunctional enzyme found in olig odendrocytes and astrocytes in normal mouse brains. We have begun to c ompare the glial cells in primary cultures from neonatal genetically C AII-deficient (Car) mice to those from normal (con) mice in order to d etect developmental defects, if any, in Car glial cells. In con cultur es intensely CAII-positive cells costained with antibodies against the oligodendrocytic markers, O4 and myelin basic protein (MBP), respecti vely. Most (82%) of the CAII-positive cells were O4-positive, but only similar to 60% were MBP-positive. Some clumps of GFAP-positive cells were CAII-positive. At each respective number of days in vitro (DIV) t otal numbers of O4-positive cells were similar in Car and con cultures , and total numbers of galactocerebroside-positive cells also were sim ilar in Car and con cultures. However, compared to cells in con cultur es at 7 DIV, a lower percent of Car cells in the oligodendrocyte linea ge expressed MBP, and morphological differentiation also was subnormal in that the Car cells showed fewer processes and membrane sheets. Car and con cultures expressed similar numbers of MBP-positive cells by 1 0 DIV. The results suggest a temporary delay in the maturation of Car oligodendrocytes.