Nematodes: nutrient and pheromone-controlled adaptations
November 14, 2013 | James Kohl
Excerpt: “These animals are genetically identical, and they were raised together in the same environment, so where do their different choices come from?”
My comment: Their choices are experience-dependent, nutrient-dependent, receptor mediated and pheromone-controlled. I detailed that fact.
Excerpt 1: …the epigenetic effects of food odors and pheromones are involved in neurogenic niche construction as exemplified in nematodes (Bumbarger, Riebesell, Rödelsperger, & Sommer, 2013)…
Excerpt 2: Differences in the behavior of nematodes are determined by nutrient-dependent rewiring of their primitive nervous system (Bumbarger et al., 2013). Species incompatibilities in nematodes are associated with cysteine-to-alanine substitutions (Wilson et al., 2011), which may alter nutrient-dependent pheromone production.
Predictably researchers will next find that species-specific pheromones associated with the cysteine-to-alanine substitutions differentially light up these nerve cells in nematodes of different species.
This will extend my model from yeasts to nematodes with even more experimental evidence that refutes mutation-initiated natural selection and replaces that ridiculous theory with nutrient-dependent pheromone-controlled adaptive evolution as should have happened when we provided details of molecular epigenetics in our 1996 review article: From Fertilization to Adult Sexual Behavior
Excerpt: Small intranuclear proteins also participate in generating alternative splicing techniques of pre-mRNA and, by this mechanism, contribute to sexual differentiation in at least two species, Drosophila melanogaster and Caenorhabditis elegans…
Caenorhabditis elegans is the model organism that led to the report on the glowing worms and their behavior: High-throughput imaging of neuronal activity in Caenorhabditis elegans
Nutrient-dependent alternative splicings cause different responses to food odors and also cause sex differences and species differences in pheromone-controlled behavior in species from microbes to man. In microbes, see for example: Signaling Crosstalk: Integrating Nutrient Availability and Sex. The molecular mechanisms are conserved across all species.
See for example in Kohl (2012): Socioaffective neuroscience and psychology may progress more quickly by keeping these apparent facts in mind: Olfaction and odor receptors provide a clear evolutionary trail that can be followed from unicellular organisms to insects to humans (Keller et al., 2007; Kohl, 2007; Villarreal, 2009; Vosshall, Wong, & Axel, 2000).
My comment to Science Magazine (as a follow up to the article Mosaic Copy Number Variation in Human Neurons)
Submitted on 11/15/13 at 07:32 and approved at 07:50 EST.
Re: Aplysia. Why not nematodes?
“High-throughput imaging of neuronal activity in Caenorhabditis elegans” http://www.pnas.org/content/110/45/E4266.full
The article helps to elucidate the conserved molecular epigenetics of cause and effect in a model organism of ecological, social, and neurogenic niche construction sans mutations theory.
Altered transcription can be associated with minimal variability in epigenetic landscapes that results in neurons with different genomes and distinct molecular phenotypes.
Effects of olfactory/pheromonal input appear to directly link the epigenetic landscape to the physical landscape of DNA in the organized genomes of species from microbes to man. In nematodes, conserved molecular mechanisms now link pulsing food odors and observed responses to the pulsatile secretion of gonadotropin releasing hormone (GnRH) in vertebrates. GnRH pulses links the epigenetic effects of food odors and pheromones to human behavior via systems biology and the ability of pulses to integrate information and rapidly transmit it throughout neuronal networks.
We can better understand the development of subtle differences in human behavior that are genetically predisposed and epigenetically effected. This will help us distinguish between genetic predisposition (nature) and effects of the sensory environment (nurture)during behavioral development.
The advantage is that we can also avoid attributing differences to mutations-initiated natural selection or to mutation-driven evolution by using what is known about biologically based cause and effect.