In the past year, the project on the developmental expression of neuropeptide genes in the Xenopus CNS was terminated. However, the developmental expression of one member of the LIM class family of homeobox genes was characterized in rat cerebellum using in situ hybridization in collaboration with Dr. V. Gallo in LCMN. Northern blot analysis showed that rat rLIM-1 expression in cerebellum was at its peak level postnatal day 8, coincident with a peak period of granule cell proliferation. A dramatic decrease was observed in rLIM-1 but internal granule cells express low levels. In developing rat cerebellum, proliferative and premigratory cells express high levels of rLIM-1 but down regulates in post-mitotic cells, coincidental with onset of migration through the molecular layer.
