Environment can affect the size of animals, a new study on ants has shown.
Height and weight, as well as intelligence and tendencies toward developing some diseases, have long been known to be influenced by both genetic as well as environmental factors. However, it is not known exactly how the two factors interact to produce these different characteristics in living beings.
McGill University researchers studied ants in an effort to determine how inheritance and environment interact in the insects. The investigators identified sections of genetic code that direct certain characteristics, including body length, and studied how they are affected by the environment. By altering the living conditions of the ants, it could be possible to alter the degree to which the gene is expressed in their bodies, researchers stated.
Florida carpenter ants (Camponotus floridanus) were examined in the study. In any colony of the insects, about three-quarters of all the insects in a given colony are related to each other, providing a genetic base with little diversity. This allowed researchers to study the effect of the environment on the insects with a standard genetic influence. The genome of C. floridanus has already been mapped, aiding the research.
A gene called Egfr plays a vital role in growth, and its expression is controlled by a biochemical process known as DNA methylation. This can act to either enhance or diminish the role played by the gene, like turning the volume switch of a radio up or down.
"Basically, what we found was a kind of cascading effect. By modifying the methylation of one particular gene, that affects others, in this case the Egfr gene, we could affect all the other genes involved in cellular growth," Sebastian Alvarado of McGill University said.
These complex traits appear to be influenced by environment as much as they are by genetics, the study revealed.
The process might be compared to adding more or less of a chaser to alcohol in order to make a drink weaker or stronger. Investigators found that by controlling the degree of DNA methylation, they were able to direct the growth of the insects. As the process became more pronounced, the insects grew larger, researchers discovered.
"So many human traits, whether they are intelligence, height, or vulnerability to diseases such as cancer, exist along a continuum. If, as we believe, this epigenetic mechanism applies to a key gene in each area, the change is so enormous that it's hard to even imagine right now how it will influence research in everything from health to cognitive development to farming," Ehab Abouheif of McGill University said.
Study of how environment interacts with genetics to produce growth in ants was published in the journal Nature Communications.
Photo: Bob Peterson | Flickr
