Polymorphism of the untranslated regions of the F3/contactin mRNA in the rat nervous system

F3/contactin is a neural adhesion molecule implicated in various physiological processes. In rat brain tissues, we cloned various mRNA with the same coding region but differing in 3′ and 5′UTR. The 3′UTR presents two polyadenylation signals. At the 5′ end, we identified two leader exons, multiple transcription initiation sites and splicing events, leading to at least 19 different 5′UTR. The F3/contactin rat gene differs from the mouse gene for two reasons: (1) it contains two additional untranslated exons that are alternatively spliced and (2) it lacks the homologue mouse untranslated exon 0.