several forms of the rat preprogrp mrna are found in brain : a 1.1 kb form which initiates in both brain and gut primarily from a tataa-directed promoter , and less abundant forms of about 1.5 kb , whose initiation sites are heterogeneous , located 300-400 base pairs upstream of the 1.1 kb initiation site , and found only in spinal cord and a subset of brain nuclei expressing preprogrp mrna .
C0006104
brain
C1706993
of brain nuclei