RESUMO
In the past few years, the plasticity of the regional specification of the CNS has been widely debated on the results from in utero transplantation. Two different results are reported with this transplantation method. One is that the distribution of transplanted cells is dependent on the donor origin, and the other is that the distribution is independent on the donor cell origin. The present study attempted to examine closely the plasticity of the regional specification by in utero transplantation method with clonal neural cell lines, 2Y-3t and 2Y-5o2b. These lines were established from a cerebellum of an adult p53-deficient mouse. Our results showed that transplanted cells migrated into various regions of the CNS and supported the independent distribution. Moreover, different distribution patterns of transplanted cells were observed between host sexes. Labeled cells were localized around the ventricle of neonatal host brains, where they were undifferentiated. In 2-3 weeks after birth, labeled cells were found in the brain parenchyma and some of them took neuronal morphology. In the rostral migratory stream (RMS), cells with unipolar or bipolar morphology were still undifferentiated. In other regions, labeled cells were often associated with blood vessels; the soma were on the surface of vessels, extending processes or neurites into surrounding brain parenchyma. Time-lapse imaging demonstrated that they were migrating with blood vessels.
