How the Environment, Not Necessarily Genetics, Controls Size in Ants

It turns out that variations in traits may not just be all down to genetics. Scientists have looked at ants and have found a key mechanism by which environmental factors influence the expression of traits that range from height to color to weight.

In this latest study, the researchers conducted epigenetic, or environment, experiments on a species of ants called Camponotus floridanus. Better known as the Florida carpenter ant, this species can vary in size even within a colony. The genome of this species had already been sequenced, which meant that the researchers could focus on the influence of epigenetic factors.

The researchers increased the degree of DNA methylation, which is a biochemical process that controls the expression of certain genes, of a gene involved in growth called Egfr. In fact, the scientists were able to create a spectrum of worker ant sizes despite the lack of genetic difference between one ant and the next. The more methylated the gene, the larger the size of the ants.

"Basically what we found was a kind of cascading effect," said Sebastian Alvarado, co-first author of the new study, in a news release. "By modifying the methylation of one particular gene that affects others, in this case the Egfr gene, we could affect all of the other genes involved in cellular growth. We were working with ants, but it was a bit like discovering that we could create shorter or taller human beings."

This latest study reveals that researchers can influence how much or how little of a gene is expressed by focusing on the key genetic position that is affected by epigenetic factors.

"It's a discovery that completely changes our understanding of how human variation comes to be," said Ehab Abouheif, one of the researchers. "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 now how it will influence research in everything from health to cognitive development to farming."

The findings are published in the journal Nature Communications.

For more great science stories and general news, please visit our sister site, Headlines and Global News (HNGN).