Comparative expression analysis of the genes encoding polypyrimidine tractbinding protein (PTB) and its neural homologue (brPTB) in prenatal and postnatal mouse brain

The polypyrimidine tract binding protein (PTB) and its recently discovered homologue brain-enriched PTB (brPTB) are RNA binding proteins involved in t he control of alternative splicing, We have characterized expression patter ns of the PTB and brPTB in course of mouse brain development, using mRNA in situ hybridization. PTB is expressed in choroid plexi and ependyma at all the stages of development and temporarily in the mantle layer of migrating neuroblasts of fore-, mid- and hindbrain and in the external granular layer of cerebellum. Ln the neurons of adult mouse cerebrum and cerebellum expre ssion of PTB is undetectable. In contrast to this, brPTB is expressed ubiqu itously in neuroblasts of various parts of embryonic brain and in the diffe rentiated neurons of postnatal cerebrum and cerebellum, brPTB mRNA is not o bserved in choroid plexi and ependymal layer. Thus. in the embryonic brain expression patterns of PTB and brPTB overlap, but in the course of brain de velopment the patterns become complementary to each other. (C) 2001 Elsevie r Science Ireland Ltd. All rights reserved.