Epigenetic Patterns Determine If Honeybee Larvae Become Queens Or Workers

Science Daily / Queen Mary University of London    August 22, 2018

Scientists at Queen Mary University of London and Australian National University have unravelled how changes in nutrition in the early development of honeybees can result in vastly different adult characteristics.

Queen and worker honeybees are almost genetically identical but are fed a different diet as larvae. The researchers have found that specific protein patterns on their genome play an important role in determining which one they develop into.

These proteins, known as histones, act as switches that control how the larvae develop and the diet determines which switches are activated. They found that the queen develops faster and the worker developmental pathway is actively switched on from a default queen developmental programme.

This change is caused by epigenetics -- a dynamic set of instructions that exist 'on top' of the genetic information, that encode and direct the programme of events that leads to differential gene expression and worker or queen developmental outcome.

The study, published in Genome Research, describes the first genome wide map of histone patterns in the honeybee and the first between any organism of the same sex that differs in reproductive division of labour.

Bees are also very important pollinators -- so it is crucial to understand their molecular biology, how they develop and the mechanisms that regulate this.

Lead author Dr Paul Hurd, from Queen Mary University of London, said: "The ability of an individual larva to become a worker or a queen is due to the way genes are switched on or off in response to the specific diet; this determines such differing outcomes from the same genome."

"We show that queens and workers have specific histone patterns even though their DNAs are the same. These proteins control both structural and functional aspects of the organism's genetic material and have the capacity to determine which part of the genome, and when, has to be activated to respond to both internal and external stimuli."

The histones have small chemical tags, or epigenetic modifications, that allow them to act differently to those that do not, usually by allowing access to the DNA and genes. This enables identical DNA to behave in different ways because it is wrapped around histones with different chemical (epigenetic) tags.

Co-author Professor Ryszard Maleszka, from Australian National University, added: "The extent of histone modifications uncovered by this study was remarkable and exceeded our expectations. We were able to identify where the important differences are in the genomes of workers and queen."

Epigenetic information can be altered by environmental factors, including diet. In the case of the honeybee, the queen larvae are fed a diet of royal jelly, a potent substance capable of changing developmental instructions.

Dr Hurd said: "Think of the genome as the instruction book of everything that is possible but the epigenetics is the way in which those instructions are read. Epigenetics is about interpretation and of course there are many different ways to interpret these instructions and when and in response to what."

The authors found that some of the most important epigenetic differences are in regions of the honeybee genome that are not part of genes. For the first time, these caste-specific regulatory DNA regions that are so important in making a queen or a worker have been identified.

Professor Maleszka said: "Our findings are important because a high level of similarity of epigenetic tool kits between honeybees and mammals makes this familiar insect an invaluable system to investigate the sophistications of epigenetic regulation that cannot be addressed in humans or other mammals."


Story Source:

Materials provided by Queen Mary University of London. Note: Content may be edited for style and length.


Journal Reference:

Marek Wojciechowski, Robert Lowe, Joanna Maleszka, Danyal Conn, Ryszard Maleszka, Paul J. Hurd. Phenotypically distinct female castes in honey bees are defined by alternative chromatin states during larval development. Genome Research, 2018; DOI: 10.1101/gr.236497.118

https://www.sciencedaily.com/releases/2018/08/180822130958.htm

Newly Named Bacteria Help Honey Bee Larvae Thrive

PHYS.org   By Kim Kaplan  May 7, 2015

ARS technician Lucy Snyder selects bee larvae from honeycombs for in vitro rearing with probiotic bacteria. Credit: Vanessa Corby-Harris

Honey bees are under constant pressure from a whole host of stresses—diseases, poor nutrition, sublethal effects of pesticides, and many others. While researchers have been aware for a number of years of a community of bacteria in adult bees that may aid with some of these stresses, Agricultural Research Service researchers have identified the first bacteria that offer a benefit to bee larvae.

Molecular biologist Vanessa Corby-Harris and microbial ecologist Kirk E. Anderson at the ARS Carl Hayden Bee Research Center in Tucson, Arizona, have named a new species of bacteria—Parasaccharibacter apium. An Acetobacteraceae so far found only in honey bees and their hives, it appears to give honey  a significantly better chance of surviving to become pupae.

Honey bees have four major life stages: egg, larva, pupa, and adult.

Work on P. apium was initiated by an earlier post-doctoral researcher, Lana Vojvodic, who first discovered that these bacteria were abundant in larvae and also thrived in . Royal jelly is a protein-rich substance produced by adult bees in their hypopharyngeal glands, which resemble bunches of grapes on each side of the head. Nurse bees secrete and feed the jelly, which may contain P. apium, to young bee larvae. This jelly is the only food bee larvae eat during their first couple days. Then they are fed increasingly more honey, which has also been found to contain P. apium in most bee hives.

In lab experiments, ARS researchers tested honey bee larvae to see whether those fed royal jelly containing the Parasaccharibacter apium bacteria survived better those fed jelly that did not contain P. apium. Credit: Stephen Ausmus

In laboratory experiments designed by Corby-Harris, bee larvae were fed either P. apium-spiked jelly or sterile control jelly. The group fed P. apium had a 20-percent better survival rate in the first trial and a 40-percent better survival rate in the second trial.

"We haven't yet identified what P. apium does that confers this survival advantage to the larvae. It could involve the production of organic acids and lowering pH, which might have an antiseptic effect, or its presence might induce an immune response that could later work against larval pathogens," Corby-Harris says.

While P. apium found in honey bee hives is a distinct and new species from any previously identified, it has very close, naturally occurring relatives found in the nectar of many flowers, including cactus flowers, daisies, thistles, and apple blossoms.

Acetobacteraceae bacteria from flowers have not been tested yet to see if any of them might provide bee larvae with the same survival benefit, nor has there been a wider survey to determine the occurrence of P. apium-like species in economically important crops visited by bees.

A honey bee larva—the second life stage of honey bees in the egg, larva, pupa, adult sequence. Credit: Stephen Ausmus

"We have sequenced the genome of P. apium and begun to dissect the functional properties that distinguish flower-living Acetobacteraceaefrom those that have coevolved with the honey bee hive. Pinpointing these ecological differences will be key to understanding the function of P. apium in  hives," says Anderson.

With minimal sampling effort, P. apium was found in nearly every one of the healthy managed  examined by the researchers. A future study will explore the abundance of P. apium in weak or struggling managed bee colonies.

While the mechanism by which the bacteria benefit the larvae remains to be studied, the importance is clear enough that Corby-Harris and Anderson are already field testing its use as a management tool. "Along with P. apium, we are testing a number of bacteria that may benefit the pollination and honey-production industry," says Corby-Harris.

"More broadly, our research suggests that a community of bacteria that includes P. apium confers a generalized hygienic quality to the hive environment," says Anderson. "So we advise against unnecessary use of antibiotics by beekeepers, as it likely disrupts the variety and balance of microbial functions occurring throughout the hive, including the antiseptic properties of honey, pollen storage, larval health, and pathogen protection."

Read more at: http://phys.org/news/2015-05-newly-bacteria-honey-bee-larvae.html#jCp
 

Explore further: Age matters: Young larvae boost pollen foraging in honey bees

Queen & Disease Clinic

NC State University - Entomology "Queen & Disease Clinic"

If knowledge is power, then one of the most effective tools in the beekeeper’s arsenal is to know the health and productivity of their bees. However, many important factors to colony health cannot be easily quantified without sophistocated techniques. The NC State Queen & Disease Clinic is now offering a wide range of analytical tools to quantify queen reproductive quality as well as queen and colony health.

Queen

The reproductive quality of queens, and the drones with which they mate, has been among the top management concerns of beekeepers for the last decade. Being able to verify cohorts of queens for their mating success, identify failing queens, or diagnosing laying problems are all helpful for successful beekeeper management. Moreover, testing queens for infection (Nosema and viruses) can also be important for improving genetic stock, since it is known that these diseases can affect queen and colony performance.


GenotypingTesting colonies for diseases and genetics is equally important. We can measure virus levels within colonies and compare them to baseline data to determine potential deviations that affect colony health. The importance of Africanized bees is also an ever-increasing threat, particularly on the Eastern seaboard, so a diagnostic genetic test is the standard means of determining Africanization. Finally, intracolony genetic diversity is important for many aspects of colony function, thus our high-throughput process of calculating effective paternity frequency of the queen (=mating number) can be useful for both the beekeeper and honey bee scientists.

Queens (or drones)

PROCESS [PER SAMPLE BASIS]
5-10
11-20
21-40
>40
Insemination quality (includes morphometric analysis, sperm viability, and total sperm count) $20.64 $18.84 $16.33 $15.17
Nosema analysis (includes morphometric analysis, Nosema species identification, and detected presence/absence) $227.47 $208.70 $183.57 $170.67
Viral analysis (includes morphometric analysis plus presenece/absence and relative levels of ABPV, BQCV, CBPV, DWV, IAPV, KBV, and SBV) $155.27 $112.39 $82.25 $71.83

Colonies (~100 workers each)

PROCESS [PER SAMPLE BASIS]
5-10
11-20
21-40
>40
Nosema analysis (includes Nosema species identification, and detected presence/absence) $227.47 $208.70 $183.57 $170.67
Mitotyping for Africanization (includes genetic analysis of maternal ancestory as African or European) $129.06 $110.29 $93.89 $86.55
Viral analysis (includes presenece/absence and relative levels of ABPV, BQCV, CBPV, DWV, IAPV, KBV, and SBV)
$155.27 $112.39 $82.25 $71.83
Genotyping analysis (includes a full assessment of paternity for 48 workers and estimate of queen mating frequency) $285.20 $242.26 $206.58 $189.28


How to arrange and ship your samples

To request a quote for any of the above services, please email us directly.Because of processing and time constraints, there is a minimum of 5 queens or colonies per order. We will then generate and email you an invoice for the requested services. Remit by check made out to “NC State University” to schedule a delivery date, or pay by credit card using our online payment system.Nexcelom

Once a date is arranged to send samples, all bees must be mailed while alive unless otherwise indicated. Overnight delivery should be made to the shipping address outlined on the invoice. No samples will be processed until payment is received.

Processing time depends on the type and number of analyses, as well as the number of samples to be measured. However, our high-throughput processing procedure typically results in sending a report within 1-2 weeks of receiving the samples.

Example Queen Bee Clinic Reports:

Reports of all analyses are summarized into a simple format that provides relative measures. This places the findings into context and makes it much easier for fast and reliable interpretation.

Scanned image of example Queen Bee Clinic Report

 Contact Queen & Disease Clinic: http://entomology.ces.ncsu.edu/apiculture/queen-disease-clinic/

Ground Honey Bee Larvae has Health Benefits

By Lady Spirit Moon June 29, 2012  (Walter T. Kelley Co./Apitherapy: Apilarnil July 5, 2012)  

Apilarnil is an acronym: 
■ Api – bee 
■ lar for larvae 
■ n for Nicolae, the first name of the man who discovered Apilarnil, and 
■ il the two initials for the discoverer’s last name, Iliesiu.

About 30 years ago in Romania, Nicolae discovered when he fed his chickens and ducks dead bees, the weak ones not only got stronger, but the birds grew faster than normal. Apilarnil is the white, almost fully formed, drone larvae. When ground, strained through special filters, and added to bee pollen, Apilarnil has compositions similar to and is administered like Royal Jelly. It is anti-viral as Royal Jelly. It’s high in nutrients for memory, and is good for male sexuality and gastro-intestinal use. Often it is administered in powder or tablet form.

Like many bee products, Apilarnil’s medicinal properties are undergoing constant research and discovery. These are amazing insects!

https://kelleybees.com/blog/2012/06/apitherapy-apilarnil/

(From Kelley's Bees Editor’s Note: Lady Spirit Moon is an ambassador for the Center for Honeybee Research,www.chbr.org. We featured the Center a few issues ago, and are making it easier for our readers to help the Center help honeybees by clicking here. The Walter T. Kelley Company will donate a dollar for every contribution our readers make. Thank you!)