2018/08/24

Histones control how DNA is read

Histones control both structural and functional aspects of our genetic hardware

https://www.scimex.org/newsfeed/honey-bees-unravel-nature-nurture-mysteries

Excerpt: "They say leaders are born not made, but it seems the opposite is true for queen bees, according to a new study by researchers from The Australian National University (ANU) and Queen Mary University of London.

Larvae turn into queen bees when they are fed a nutritious diet called ‘royal jelly’.

Royal jelly has the capacity to influence the genetic instructions encoded in the honey bee genome, a process called ‘epigenetics’ or ‘above genetics’.

So how does this quirk of nature actually work?

“We hypothesised that royal jelly acts via a special class of proteins called histones that are directly associated with DNA and control both structural and functional aspects of our genetic hardware,” Ryszard Maleszka from the ANU Research School of Biology said.

“These proteins are modified by various chemical tags, which provides them with the needed flexibility to coordinate the expression of all genes and respond to changing extremal conditions.”

Bees are eusocial insects, meaning there’s usually one individual who reproduces (the queen) and the rest of the females in the colony perform a large repertoire of tasks.
 

They all start out with the same genetic blueprint, but differential feeding controls their developmental fate, setting a larva on the path to becoming a queen, or a sterile worker.

The study found big differences in genes involved in certain behaviours and brain development.

The extent of histone modifications uncovered by this study is remarkable and exceeded our expectations. We were able to identify where the important differences are in the genomes of workers and queen,” Dr Paul Hurd from Queen Mary University said.

“We suspect here might even be specific enhancers in the genome that determine worker phenotype or queen phenotype and it might be possible in the future to manipulate those and see how we can reverse or change the trajectory.”

The workers have a much more enhanced development of the brain and neural-system, which is consistent with their sophisticated adult behaviours such as navigation, communication and long-term memory.

As expected, the queen was found to have more enhanced metabolic processes and reproductive features.

While more research is required to find a more definitive answer on the potential benefits of royal jelly to humans, these findings could change the way we look at our own diets.

“It could help us gain some understanding of what happens to humans or mammals in general when they overeat or change their dietary habits,” Professor Maleszka said."

My comment: DNA is just a passive information library for the cell. DNA is not your destiny. DNA doesn't dictate traits of an organism. DNA has no control over cellular processes. Epigenetic factors and mechanisms have the control.