“Gene mapping reveals architecture that controls expression of genes responsible for our sense of smell.” May 18th, 2012. Full text of the article cited (published in March 2012).
Excerpt 1: “OR promoters have therefore characteristics of non–nervous tissue–restricted genes. In the brain, the list of tissue-restricted genes that have TATA-box, non-CpG island sharp promoters includes retina-specific genes such as opsins, retbindin, and retinal S-antigen. Resemblances in the transcriptional control of those genes may be due to a similar role as sensory transduction elements with an early origin in evolutionary history, thus sharing the more ancient type of tissue-restricted regulation that is based on sharp, TATA-boxed promoters.”
My comment 1: The early origin of olfactory receptor genes predates retina-specific genes and attests to the relative salience of olfactory/pheromonal stimuli compared to visual stimuli across species from microbes to man, since many of these species don’t have eyes.
Excerpt 2: “Among the other mechanisms that can globally control gene expression, epigenetic modifications of the DNA or the chromatin may be a good complement, for instance, to select a single locus in which interaction between a shared enhancer and the stereotyped OR core promoters would then trigger the selection of a single OR gene.”
My comment 2: This suggests that adaptation of the CAGE technique for single cells will allow them to detail how nutrient chemicals cause the receptor-mediated changes in intracellular signaling and stochastic gene expression that lead to de novo olfactory receptor gene expression. These changes lead to new nutrient dependent ecological niches accompanied by social niches that are standardized and controlled by pheromones.
In the honeybee invertebrate model, and stickleback vertebrate model the nutrient chemicals and pheromones control brain development and speciation. These model organisms and other model organisms make clear the extension of the concept to nutrient chemical and pheromone-dependent neurogenic niches, human brain development, and individual differences in behavior. Sex differences in brain development and behavior are as readily linked to sex differences in pheromones as they are in every other species that reproduces sexually, from yeasts to other primates. So, why is this in the current news several months after its publication? Did someone suddenly realize that their results could be meaningfully interpreted? Shall we compare them to any other results that might be relevant to the evolution of the human brain and behavior?
If so, you start! But first, is there a model for that!