The nucleotide sequences containing the rat interleukin-12 p40 gene wa
s determined. Sequencing revealed the presence of sis exons and five i
ntrons, Analysis of the 5' non-coding region showed the presence of se
veral possible sites involved in cytokine gene regulation at the trans
criptional level, Comparison of the deduced amino acid sequence of rat
IL-12 p40 with that of the mouse and of human p40, showed 92% and 65%
identity respectively.