Tuesday, 15 May 2012

So Bees Have Personalities, Who Knew?

By Kelsie O'Leary

Figure 1 - Apis mellifera or Western Honey Bee [7]
A recent article published earlier this month documents the genetic differences within bee hives that promote the tendency to explore. These bees, called scouts, are known for searching for new possible hive locations and food sources even when there are sufficient known sources already available.  What’s interesting about this is that only scout bees do this, and never ‘non-scout’ bees [1]. This phenomenon interested Gene. Robinson, a professor of Entomology at University of Illinois, who lead the project. He asked the question "In humans, differences in novelty-seeking are a component of personality, Could insects also have personalities?" [2] , and set out to answer it; and answered he did.

The experiment was undertaken in three parts, the first involving the relocation of several natural and artificial hives of bees to an unfamiliar environment. They then observed the bee’s behaviour when searching for food sources and found that bees that would search for new food sources were typically ‘nest scouts’, which are bees that would usually find a new and more suitable location for a hive [1]. This shows that there is something atypical about the scout bees that make them preform these jobs, while other members of the hive don’t.

Figure 2 - [8]
The second part of the experiment involved determining whether the genomic sequence had anything to do with this unusual behaviour. To do this, the bee hives were again relocated into an enclosure and the bees were lead to a single food source for a period of time until the bees were ‘trained’ to gather food form this area. Then, a couple of days later, another food source was added to the enclosure and any bee that used this food source was marked with a specific colour. This process, seen in figure 2, was repeated for three days. At the end of the experiment, bee’s that were seen at, at least two of the new food sources and at the original food source were considered as scouts [1].

Then the collect scout bees genetic material was compared to non-scout bees, who never visited different food source. This showed a an almost 16% difference between scout and non-scout bee’s mRNA, with many of these differences in the expression of genes related to catecholamine, glutamate and y-aminobutyric acid signalling [1]. These chemicals can all been related back to the novelty seeking behaviour that is evident in the ‘scout’ bees.

The third part of the experiment took these findings further and tested the effects of these chemicals on non-scouting bees to determine their effects. The results showed that glutamate ‘caused a significant increase in scouting’ [1] and a dopamine blocker caused a significant decrease in scouting’[1]. These outcomes illustrated their expected results and proving that these chemicals have everything to do with the ‘novelty seeking’ personality in these bees.

So bees have personality. Who knew? These results are expected to shed light on behavioural genetics and help us understand where personality developed in the evolutionary map. It maybe, but unlikely, that humans and bees personality developed personality from a common ancestor; but more likely that it was developed side by side as time went on [1]. 


References 


[1] Liang, Nguyen, Mattila, Rodriguez-Zas, Seeley & Robinson; 2012; ‘Molecular Determinants of Scouting Behavior in Honey Bees’; Science, vol 335, no. 6073, released on 9th March 2012, <http://www.sciencemag.org/content/335/6073/1225.full>
[2] ScienceDaily; 2012; Insects Have 'Personalities' Too, Research On Novelty-Seeking Honey Bees Indicates; viewed 18th March 2012, < http://www.sciencedaily.com/releases/2012/03/120308143201.htm>
[3] Healthwise Staff; 2010; Health Library: An extensive resource for information on illnesses, conditions, drugs, medical tests, and more., Catecholamines; Viewed on 18th March 2012;
[4] Psychology Today; PSYCH BASICS: Dopamine; viewed 18th March 2012; <http://www.psychologytoday.com/basics/dopamine>
[5] N. Danbolt; Glutamate as a Neurotransmitter - An overview; viewed 18th March 2012; <http://www.neurotransporter.org/glutamate.html>
[6] SM Vereshtchagin; 1961; The effect of γ-aminobutyric acid and β-alanine on bioelectrical activity of nerve ganglia of the pine moth caterpillar (Dendrolimus pini); Viewed 18th March 2012; <http://www.sciencedirect.com/science/article/pii/S0166223607001336>
[7] LP Aiello, European Honey Bee on Stoncrop Flowers; http://wildernessportraits.photoshelter.com/image/I0000lOB4S_eqPno
[8] Liang, Nguyen, Mattila, Rodriguez-Zas, Seeley & Robinson; 2012; ‘Fig. 1’; Science, vol 335, no. 6073, released on 9th March 2012, <http://www.sciencemag.org/content/335/6073/1225.full>

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