Some of the neuropeptides the researchers discovered were a result of direct measurements of bee brains using an extremely sensitive mass spectrometer. Some of the genes were found because they resembled genes discovered in other species, such as the fruit fly (Drosophila melanogaster). And, because genes that produce neuropeptides often have repeating sequences, some of the genes were found by a computer algorithm that scanned the honey bee genome for such telltale sequences.
"We found 36 genes, from which we detected 100 peptides by mass spectrometry," said Sweedler, who also is a researcher at the university's Beckman Institute for Advanced Science and Technology and an affiliate of the university's Institute for Genomic Biology. "By combining other techniques, from bioinformatics to proteomics, we inferred an additional 100 peptides."
Some of the inferred peptides may not have been measured because they were present at too low a level to be detected, Sweedler said. Others may have been missed because they are present only during particular developmental stages. Future work will no doubt find and confirm more of the brain's peptides.
"The potential of our blended technology approach to facilitate discovery of these peptides is not only significant for advancing honey bee research," the researchers wrote, "it demonstrates promise for neuropeptide discovery in the large number of other new genomes currently being sequenced."