Transgenerational epigenetic inheritance of sexual orientation

The Scientist

News & Opinion

Controlling Bee Fate

Reversible marks on the genome allow honeybees to swap between lives as nurses and foragers.

By Ed Yong | September 16, 2012

Excerpt: “Bees start off as nurses and then become foragers,” said Gro Amdam of Arizona State University, who co-authored the study. “It’s as different as being a scientist or journalist. It’s really amazing that they can sculpt themselves into these two roles that require very specialist skills.”

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My comment: Actually, it may be as different as being a heterosexual or homosexual organism. The adaptive plastic behavior that allows organisms such as bees to respond to their immediate environment with epigenetically-determined changes in their behavior was predicted by what is known about the adaptive evolution of sexual reproduction in microbes. Sex differences in behavior (e.g., in yeasts) appear to result from gene duplications driven by the need for genomic adaptation to a changing nutrient chemical environment, as evidenced in paralogues of genes that enhance the ability to use glucose.

Cellular metabolism of nutrient chemicals to pheromones allows conspecifics to recognize and to learn and to remember what evolved to become the epigenetic effects of what we call sex pheromones that control reproduction in all species — as pheromones also do in asexual microbes prior to the evolutionary advent of sexual reproduction.  The difference in behaviors that adaptive evolution has established via ecological, social, neurogenic, and socio-cognitive niche construction in the honeybee model organism are simply an extension of the epigenetic effects of nutrient chemicals and pheromones that were transgenerationally inherited via the behavior of species from microbes to man.

The concept that is extended is the epigenetic tweaking of immense gene networks in ‘superorganisms’ (Lockett, Kucharski, & Maleszka, 2012) that ‘solve problems through the exchange and the selective cancellation and modification of signals (Bear, 2004, p. 330)’. It is now clearer how an environmental drive probably evolved from that of food ingestion in unicellular organisms to that of socialization in insects. It is also clear that, in mammals, food odors and pheromones cause changes in hormones such as LH, which has developmental affects on sexual behavior in nutrient-dependent, reproductively fit individuals across species of vertebrates.” — Kohl (2012)

Oddly, what we presumed in 1996 to be a known established biological fact when we published our Hormones and Behavior review, titled: From fertilization to adult sexual behavior, may not have been fully considered and may not be now, in the light of new evidence that can be integrated across disciplines and across species in the context of transgenerational epigenetic inheritance of bee behavior. But the epigenetic effect on behavior in the honeybee can not truly be considered the first evidence that DNA methylation alters behavior, can it?

Sexual orientation in any species is epigenetically and transgenerationally linked to their survival despite wide variations in nutrient-dependent, stress-dependent, endocrine disruptor-dependent and pheromone-dependent sexual behaviors. We wrote: Parenthetically it is interesting to note even the yeast Saccharomyces cerevisiae has a gene-based equivalent of sexual orientation (i.e., a-factor and alpha-factor physiologies). These differences arise from different epigenetic modifications of an otherwise identical MAT locus (Runge and Zakian, 1996; Wu and Haber, 1995).

Since the epigenetic effects of these modifications on sexual orientation and associated behaviors in a unicellular organism were known 16 years ago, does anyone else wonder why they now appear to show up only in the behavior of the honeybee model organism?

About James V. Kohl 1307 Articles
James Vaughn Kohl was the first to accurately conceptualize human pheromones, and began presenting his findings to the scientific community in 1992. He continues to present to, and publish for, diverse scientific and lay audiences, while constantly monitoring the scientific presses for new information that is relevant to the development of his initial and ongoing conceptualization of human pheromones. Recently, Kohl integrated scientific evidence that pinpoints the evolved neurophysiological mechanism that links olfactory/pheromonal input to genes in hormone-secreting cells of tissue in a specific area of the brain that is primarily involved in the sensory integration of olfactory and visual input, and in the development of human sexual preferences. His award-winning 2007 article/book chapter on multisensory integration: The Mind’s Eyes: Human pheromones, neuroscience, and male sexual preferences followed an award winning 2001 publication: Human pheromones: integrating neuroendocrinology and ethology, which was coauthored by disinguished researchers from Vienna. Rarely do researchers win awards in multiple disciplines, but Kohl’s 2001 award was for neuroscience, and his 2007 “Reiss Theory” award was for social science. Kohl has worked as a medical laboratory scientist since 1974, and he has devoted more than twenty-five years to researching the relationship between the sense of smell and the development of human sexual preferences. Unlike many researchers who work with non-human subjects, medical laboratory scientists use the latest technology from many scientific disciplines to perform a variety of specialized diagnostic medical testing on people. James V. Kohl is certified with: * American Society for Clinical Pathology * American Medical Technologists James V. Kohl is a member of: * Society for Neuroscience * Society for Behavioral Neuroendocrinology * Association for Chemoreception Sciences * Society for the Scientific Study of Sexuality * International Society for Human Ethology * American Society for Clinical Laboratory Science * Mensa, the international high IQ society