Expression analysis of the 5'-upstream region of mouse P/Q-type Ca(2+) channel alpha( lA) subunit gene fused to Escherichia coli lacZ reporter gene in the spinal cord using transgenic mice.

The P/Q-type Ca(2+) channel alpha(1A) subunit is expressed in spinal cord including ventral motor neurons and interneurons and dorsal horn. To identify the transcriptional mechanisms of the mouse alpha(IA) subunit gene in spinal cord, transgenic mice carrying a 0.5, 1.5, 3.0 or 6.3-kb 5'-upstream region fused to the Escherichia coli lacZ reporter gene were examined. Transgenic mice carrying the 3.0-kb region expressed the reporter gene in dorsal horn and interneurons of ventral horn, although those with the 0.5-kb, 1.5-kb or 6.3-kb region did not. No transgenic mice expressed the reporter gene in motor neurons of ventral horn. These results suggest that in spinal cord, the expression mechanisms of the alpha(1A) subunit gene are complex, involving both positive and negative cis-regulatory elements, and the 6.3-kb 5'-upstream region alone is not sufficient for the expression.