What does it mean for a community that focuses on one organism to have that organism’s genome sequenced? Just ask researchers who gathered this week at the Honey Bee Genomics and Biology Meeting at the Cold Spring Harbor Laboratory on Long Island, New York. It’s the first time such a conference has been held since the honey bee genome was sequenced, and over the course of the past three days it’s become abundantly clear that this is a field transformed, greatly expanded and diversified from just four years ago.
“Before the genome… studying bees was kind of esoteric,” says Harland Patch, a behavioral genomicist at Penn State University in University Park, Pennsylvania. “But since the genome, you have these genomic molecular tools, you have a lot of people coming into the field with new skill sets, new money, as well as very interesting problems.”
Some of those problems could be crucial to the well being of honey bees and their all-important role as pollinators of food crops. They include factors related to Colony Collapse Disorder (CCD), a syndrome which began devastating Western honey bee (Apis mellifera) colonies in the US around the same time the genome was being sequenced. The urgency of the CCD crisis, along with the arrival of a new way to explore honey bee susceptibilities and genetic defenses has brought a flood of new researchers into the field.
“We were stumbling along with less than 10 immune genes before the genome,” says Jay Evans, a research entomologist at the US Department of Agriculture’s Bee Research Laboratory in Beltsville, Maryland. "And then with the genome we had a hundred or more instantly.”
Researchers have been able to identify new bee pathogens and start suggesting new ways to mitigate their threats, Evans adds. And scientists have begun to answer questions about variations in immune response and what type of pathogens trigger those responses.
“These were questions that were already there that weren’t really being addressed because we didn’t have the tools,” Evans says.
Then there are those scientists, formerly from outside bee research, who study epigenetics – heritable changes in gene expression that don’t involve changes to the underlying DNA. It turns out that unlike Drosophila melanogaster (the first insect genome to be sequenced) the honey bee is fully capable of tagging genes with methyl groups to change gene expression in the long term, a process known as methylation. Scientists used to think insects lacked this ability.
“Before, nobody realized that drosophila was the outlier,” says Greg Hunt. After the honeybee, many other insect genomes have been sequenced and were also found to have methylation genes, he adds. “We’re learning a lot more about insects in general, social insects in particular.”
Others have started looking at the genes involved in producing the different bee types in a colony. Queens, nurses and foragers all have the same genome, but have vastly differing body characteristics and behaviors depending on their type. Researchers want to know which factors affect which genes and act to change regulation over a lifetime.
Still others have flocked to honey bee research to pick apart how social behavior evolved. By comparing bees with other social insects such as ants, as well as solitary insects, they can use comparative genomics to figure out if new genes arose or if old ones were co-opted to produce social behavior.
“For anyone interested in the evolution of complex traits, this is a nice system where we can do comparative work,” says Christina Grozinger, an entomologist at Penn State.
But all this genomic information is also changing the necessary skill set of future scientists, says Olav Rueppell of the University of North Carolina at Greensboro.
“I am thrilled by the computational progress, and I’m a little bit daunted, too,” he says. “I’m thinking about my students and how unprepared they are for doing projects that involve gigabytes of data and computational methods. I’m coming away with the feeling that we need to change our undergraduate curriculum to build in more math, more computers.”
And even with a sequenced honey bee genome, there are many more questions that remain to be answered, starting with: what do all these genes do?
“After this hype of all the genome projects, we are now in need of people who know about physiology and behavior and we have to come back to the tedious task of figuring out what all these genes do,” says Dorothea Eisenhardt, a junior professor at the Freie Universitat Berlin in Germany.
One thing the arrival of the honey bee genome has not done is hand bee researchers all the secrets of their favourite organism laid out in a convenient recipe book — an often overused metaphor. Instead, says Patch, “the genome has opened up a huge vista that is seemingly unending.”