TEMPORAL AND SPATIAL CHANGES IN GATA TRANSCRIPTION FACTOR EXPRESSION ARE COINCIDENT WITH DEVELOPMENT OF THE CHICKEN OPTIC TECTUM

The molecular mechanisms specifying patterns of gene expression in the vertebrate brain, which in turn determine the developmental fates of specific neurons, are yet to be clearly defined. Individual members of a recently identified family of transcriptional regulatory proteins, the GATA factors, are required for the differentiation of certain hema topoietic cell lineages. We show here that two of the members of this gene family, GATA-2 and GATA-3, are expressed within discrete cell pop ulations of the chicken optic tectum during embryogenesis, and that th ey have highly restricted patterns of expression in the developing chi cken brain. Furthermore, the induction of GATA factor expression withi n specific cell layers parallels the well established spatial (rostral to caudal) and temporal pattern of optic tectum development. The obse rvation that both the timing of appearance and the localization of exp ression of GATA-2 and GATA-3 are correlated with optic tectum developm ent suggest that these transcription factors may be associated with th e initiation of gene transcription required for the determination of s pecific neuronal fates within visual areas of the vertebrate brain.