RESUMO
Ligands for only two human olfactory receptors are known. One of them, OR1D2, binds to Bourgeonal, a volatile chemical constituent of the fragrance of the mythical fl ower, Lily of the valley or Our Lady’s tears, Convallaria majalis (also the national fl ower of Finland). OR1D2, OR1D4 and OR1D5 are three full-length olfactory receptors present in an olfactory locus in the human genome. These receptors are more than 80% identical in DNA sequences and have 108 base pair mismatches among them. Apparently, these mismatch positions show no striking pattern using computer pattern recognition tools. In an attempt to fi nd a mathematical rule in those mismatches, we fi nd that an L-system generated sequence can be inserted into the OR1D2 subfamily-specifi c star model and novel full-length olfactory receptors can be generated. This remarkable mathematical principle could be utilized for making new subfamily olfactory receptor members from any olfactory receptor subfamily. The aroma and electronic nose industry might utilize this rule in future.