Queen Bee Microbiomes Differ From Those of Worker Bees

 DigitalJournal.com/Science   By Sravanth Verma     March 14, 2015 

Researchers from the University of Indiana have published the very first comprehensive analysis of queen honey bee gut bacteria, and have reported that these defer markedly from those of worker bees.


The gut bacteria (gut microbiomes) are generally transmitted through the maternal line, in contrast with the findings of the honey bee (Apis mellifera). Study co-author Irene L.G. Newton, also an assistant professor of biology at the University of Indiana said, “In the case of the honey bee, we found that the microbiome in queen bees did not reflect those of worker bees — not even the progeny of the queen or her attendants. In fact, queen bees lack many of the bacterial groups that are considered to be core to worker microbiomes.”

Unlike most other mammals, including human beings, honey bees' gut bacteria transmission takes place through the insect's environment and social context, which is referred to as horizontal transmission. Thus, the striking differences between queen bee and worker bee diet and environment are reflected in the microbiome. Queens usually consume protein-laden royal jelly and have very limited exposure to the outside world and the rest of the comb, besides her nest. Workers by contrast feed on “bee bread” and travel about quite a bit.

“In some ways, the development of the queen microbiome mirrors that of workers, with larval queens’ associated bacteria resembling those found in worker larvae,” Newton said. “But, by the time they mature, queens have developed a microbial signature distinct from the rest of the colony.”

Honey production and bee-keeping is a multi-million dollar business thanks to the many uses and benefits of honey. Bee keepers sometimes remove a queen bee and transfer them to new hives. Based on this study, such practices may not have a detrimental effect on colony health.

“Because the queen microbiome does not reflect the workers within a specific colony, the physical movement of queens from one colony environment to another does not seem to have any major effects on either the queen gut or worker gut communities,” Newton said.

The study titled "Characterization of the honey bee microbiome throughout the queen-rearing process" was published in the journal Applied and Environmental Microbiology, in February 2015.

Read more: http://www.digitaljournal.com/science/queen-bee-microbiomes-differ-from-those-of-worker-bees/article/428288#ixzz3V91zcwuS

Single Gene Separates Queen From Workers

Michigan State University    Contacts: Layne Cameron, Zachary Huang   1/29/14

Scientists have identified how a single gene in honey bees separates the queens from the workers.

A team of scientists from Michigan State University and Wayne State University unraveled the gene’s inner workings and published the results in the current issue of Biology Letters. The gene, which is responsible for leg and wing development, plays a crucial role in the evolution of bees’ ability to carry pollen.

“This gene is critical in making the hind legs of workers distinct so they have the physical features necessary to carry pollen,” said Zachary Huang, MSU entomologist. “Other studies have shed some light on this gene’s role in this realm, but our team examined in great detail how the modifications take place.”

The gene in question is Ultrabithorax, or Ubx. Specifically, the gene allows workers to develop a smooth spot on their hind legs that hosts their pollen baskets. On another part of their legs, the gene promotes the formation of 11 neatly spaced bristles, a section known as the “pollen comb.”

The gene also promotes the development of a pollen press, a protrusion also found on hind legs, that helps pack and transport pollen back to the hive.

While workers have these distinct features, queens do not. The research team was able to confirm this by isolating and silencing Ubx, the target gene. This made the pollen baskets, specialized leg features used to collect and transport pollen, completely disappear. It also inhibited the growth of pollen combs and reduced the size of pollen presses.

In bumble bees, which are in the same family as honey bees, queens have pollen baskets similar to workers. In this species, Ubx played a similar role in modifying hind legs because the gene is more highly expressed in hind legs compared to front and mid legs.

Besides honey bees, which aren’t native to North America, there are more than 300 species of other bees in Michigan alone. These include solitary leaf cutter bees, communal sweat bees and social bumble bees.

“The pollen baskets are much less elaborate or completely absent in bees that are less socially complex,” Huang said. “We conclude that the evolution of pollen baskets is a major innovation among social insects and is tied directly to more-complex social behaviors.”

Future research by Huang may pursue investigating how bees could be improved to become better pollinators. While this won’t provide a solution to bee colony collapse disorder, it could provide an option for improving the shrinking population of bees’ pollen-collecting capacity.

Huang’s research is supported in part by MSU AgBioResearch.

See more at: http://msutoday.msu.edu/news/2014/single-gene-separates-queen-from-workers/#sthash.ASB4RXEQ.dpuf

 Source: Michigan State University

A Day in the Life of a Single Worker Bee

Bug Squad - Happenings in the Insect World   By Kathy Keatley Garvey   5/7/13

A day in the life of a single worker bee...

A honey bee tumbles off the flowering catmint (Nepeta) and struggles to right herself. 

Her wings tattered, her body battered, she does not buzz away.

Perhaps she is approaching the end of her six-week lifespan--three weeks working inside the hive and three weeks working outside the hive. Bee scientists say that worker bees literally work themselves to death.

As a forager, she likely made about 40 trips a day gathering nectar and pollen.  Forty trips a day. It's like going to the grocery store 40 times a day. Oops, forgot something. Got to return to the store.

Bees can forage from a distance of up 5 miles away from their colony, according to Extension apiculturist Eric Mussen of the UC Davis Department of Entomology.

She's just one bee of about 60,000 in the colony. And now, she will not return. She may have eaten something she shouldn't have or may have an intestinal infection, surmised  Mussen. 

Or maybe she was poisoned by a pesticide, snagged by a bird, bitten by a spider, or ravaged by Varroa mites.

Still, seeing a honey bee tumble off a blossom and die is something we humans rarely observe. 

Meanwhile, her sisters keep working the blossoms, tasks needed to keep the colony alive. Back at the hive, the queen bee is busily laying about 2000 eggs a day to replace all the adult bees who die every day.

A day in the life of a single worker bee...


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