Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The social life of honeybees coordinated by a single gene

07.03.2007
Students of the evolution of social behavior got a big boost with the publication of the newly sequenced honeybee genome in October 2006. The honeybee (Apis mellifera) belongs to the rarified cadre of insects that pool resources, divide tasks, and communicate with each other in highly structured colonies. Understanding how this advanced state of organization evolved from a solitary lifestyle has been an enduring question in biology.

In a new study published in PLoS Biology, Mindy Nelson, Kate Ihle, Gro Amdam, and colleagues reveal one possible path to community by showing that a single gene controls multiple traits related to honeybee sociability. First characterized for its role in reproduction, the gene, vitellogenin, is widely found in egg-laying insects, which depend on it for egg cell development.

A honeybee’s lot in life depends on its age, gender, and caste. Reproduction falls to the queen and drones, while essentially infertile females, the workers, perform all the other duties required to support the colony. As young adults, workers tend larvae and perform assorted tasks in the hive. After about three weeks, they switch from domestic chores to foraging, and eventually specialize in pollen or nectar collection.

Scientists began to suspect that the protein synthesized from the vitellogenin gene—vitellogenin—might affect these social life history traits in honeybees as it became clear that the protein supported an array of functions not directly linked to egg-laying. For example, sterile workers synthesize vitellogenin to make the royal jelly they feed larvae. It can also prolong the lifespan of both workers and the queen by reducing oxidative stress.

... more about:
»foraging »honeybee »hormone »juvenile »nectar »vitellogenin

As bees undergo the complex behavioral shift demanded by the change in job description, their physiology changes too: they have higher levels of juvenile hormone and lower levels of vitellogenin. It was speculated that these two physiological factors repress each other to affect the bees’ behavior, with vitellogenin repressing juvenile hormone in younger bees to inhibit the shift from nest to field, and juvenile hormone repressing vitellogenin in bees that have switched to foraging to ensure that they stay true to their task and do not revert to nest jobs. In a previous study, the researchers also proposed that changes in vitellogenin gene expression early in life could foster the selective behavior that creates the division of labor between pollen and nectar specialists.

To test these proposed roles of vitellogenin in coordinating the social life of the honeybee, Nelson et al. inhibited the expression of the vitellogenin gene with RNA interference (RNAi). This gene-silencing tool introduces a double-stranded RNA (dsRNA) product whose sequence is complementary to a target gene, thereby setting off a series of events that ultimately “knocks down” the target gene. The researchers injected a vitellogenin dsRNA preparation into the abdomen of a subset of bees and compared their behavior and lifespan to a control group. (The control group also received a dsRNA treatment designed to mimic the stress of experimental handling without affecting gene expression.) The bees’ vitellogenin levels were monitored at 10 days, 15 days, and 20 days old to make sure the RNAi effects persisted.

Compared to controls, dsRNA-treated bees had consistently lower levels of vitellogenin protein. These vitellogenin “knockdowns” started foraging at a younger age than controls—confirming that vitellogenin affects workers’ occupational fate by repressing the shift from domestic to foraging tasks. The foragers also showed a preference for nectar, in keeping with evidence that workers genetically predisposed toward nectar have lower vitellogenin levels before leaving the nest, while those predisposed toward pollen have higher levels. But more directly, the researchers argue, these results show that vitellogenin controls social foraging specialization. What’s more, the vitellogenin-deficient bees died earlier than the controls, demonstrating the protein’s influence on honeybee longevity.

Altogether, these results demonstrate that vitellogenin regulates the organizational structure of honeybee society by influencing workers’ division of labor and foraging preference. Vitellogenin, the researchers conclude, controls not only when bees start foraging and how long they live, but what they forage. Higher levels early in life favor pollen; lower levels favor nectar. Since current methods cannot yet distinguish the effects of vitellogenin from those of juvenile hormone, the researchers argue that the two physiological factors should be considered as partners in mediating task assignment and specialization. Since this partnership is uncommon in insects, it suggests that social behavior in honeybees emerged from a makeover of relations between vitellogenin and juvenile hormone. It also bolsters the notion that factors normally in control of female reproduction can lay the foundation for the transition from solitary life to complex social behavior.

Natalie Bouaravong | EurekAlert!
Further information:
http://www.plos.org
http://www.plosbiology.org

Further reports about: foraging honeybee hormone juvenile nectar vitellogenin

More articles from Life Sciences:

nachricht A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
21.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Nagoya physicists resolve long-standing mystery of structure-less transition

21.08.2017 | Materials Sciences

Chronic stress induces fatal organ dysfunctions via a new neural circuit

21.08.2017 | Health and Medicine

Scientists from the MSU studied new liquid-crystalline photochrom

21.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>