A Comparison of the Evolutionary Distribution of the Two Neuroendocrine Markers, Neurone‐Specific Enolase and Protein Gene Product 9.5

Abstract

One‐ and two‐dimensional polyacrylamide gel electrophoresis followed by immunoblotting has been used to examine the phylogenetic distribution of the two neuronal and neuroendocrine proteins, neurone‐specific enolase and protein gene product 9.5, in animal brains. A new immunoblotting procedure was used in which complex two‐dimensional patterns of brain proteins were transferred to nitrocellulose paper simultaneously with the Coomassie Blue stain. This produced a copy of the blue spot pattern against which brown protein spots reacting in a specific antibody‐immunoperoxidase procedure could be identified unequivocally. Extracts of human, bovine, sheep, rabbit, rat, guinea‐pig, chicken, trout, and frog brains were examined. Proteins cross‐reacting with antisera to the human forms of both proteins could be demonstrated in all species examined. This suggests that proteins corresponding to neurone‐specific enolase and protein gene product 9.5 could have evolved at least 400 million years ago and have been highly conserved throughout evolution.