NSE-BCL-2 TRANSGENIC MICE, A MODEL SYSTEM FOR STUDYING NEURONAL DEATHAND SURVIVAL

Bcl-2 is a crucial regulator of cell survival and death. We have recen tly demonstrated that transgenic mice overexpressing the human Bcl-2 p rotein specifically in their neurons have an increased number of neuro nal cells which can survive in tissue culture in the absence of neurot rophic factors. In order to understand why only some neurons can be re scued from developmental and neurotrophic factor deprivation-induced d eath, we have studied the expression pattern of the transgene during e mbryonic development and in adulthood. We have demonstrated that trans gene expression starts in embryos at E12.5 and that only half of the s ensory neurons of the dorsal root ganglia expressed detectable levels of the human Bcl-2. These results may explain why only 40% of the sens ory neurons survived in tissue culture in the absence of neurotrophic factors.