As an avid reader of Science Daily, I found a report describing an experiment conducted by Wang et al. that used bees to investigate whether the role of genes in eating. With a personal interest in nutrition, especially unwise food decisions that humans make, I was instantly hooked.

I am completely for the use of appropriate animal models in scientific studies. "Appropriate" in that meaningful data and inferences (i.e. for use in medicine or understanding the world) can be made from the use of these animals. While the specter of mid-twentieth century animal experimentation may hover over the field, such as Soviet experimentation in reviving severed dog heads (Apocal 2006), the use of animals has progressed far. Legally, acquiring funds for such experimentation requires strict adherence to laws surrounding the humane treatment of animals; other professional and regulatory bodies, such as the APA, may have further guidelines (APA 2010).

More practically, humans have a sounder understanding of proper scientific experimentation. Procedural errors were made in the 1950's experiment relating lung volume to blood oxygen volume, especially the lack of a controlled subject pool. Dogs were perhaps acquired willy-nilly, without respect to breed, overall health, or age, which made drawing sound conclusions from statistics gathered from the experiment virtually useless without further weeding. Furthermore, We now know far more about animal systems and can find closer analogues to human systems in the non-sapient animal world: dogs have been used to model behavioral conditioning; cats in studies examining the visual sensory system and in facial recognition; and Wang et al., bees used for their close metabolic analogue to humans.

Wang et al. set out with to answer if the IRS gene in bees influence food choices. The treatment was the presence or absence of IRS gene. The response variable was whether the bee preferred protein-rich pollen or sugar-rich nectar. Because of their metabolism and since virtually all aspects of insects, from genotype to environment, can be tightly controlled, bees made for excellent subjects in this experiment (Wang et al. 2010).

The scientists were very careful in their experimental design. Their bees came from well-recorded lineages and the bees chosen to receive the IRS knockdown treatment were randomly chosen from the bee stock when still eggs. When testing the bees' food preferences, the bees were placed into the exact same situation and the observer did not know if the bee he was testing was a control or not, keeping true to the notion of a double-blind experiment. In testing the relationship between IRS-deficiency and food choices, a pool of 150 control bees and 150 IRS-deficient bees were used. A few bees from each pool were discounted from the results due to various reasons (death during experiment or inability to distinguish between pollen and nectar).

All of this served to limit any undesirable sources of variability so that any conclusions from the experiment could be traced to the only significant difference in the bees: the presence or suppression of IRS gene. The scientists did as much as they could to eliminate variation among individuals; the bees were raised from the same pedigreed lineages and all but built from the ground-up with regards to their genes. Except for genetic treatments (i.e. presence or absence of the IRS gene), the bees were effectively the same.

In testing the bees' responses to pollen nectar, and honey, the bees were chilled until nearly immobile, and then presented with samples of food. While this may seem cruel if the bee were replaced by a dog or a person, I am at a loss to propose alternate tests for an insect. The insects certainly weren't starved for any period of time, merely given a (very narrow) choice of food. I must applaud the scientists for the simplicity of the choice and the bare minimum amount of suffering dealt to the bees.
Their data, summarized in various graphs and blots, show significant differences in the nectar and pollen load between control bees and IRS-deficient bees. Statistically speaking, the proportion of pollen carried by IRS-deficient bees was far greater than control bees; even the control bees' most pollen-rich outliers did not reach the IRS-deficient bees' average proportion of carried pollen.

However, there are always risks in experimenting with non-human subjects. There may always be some unforeseen difference between humans and the given animal that render certain findings if not useless, unfeasible for human use, e.g. in pharmaceuticals. Furthermore, certain fundamental differences exist between humans and animals, such as anatomical differences, not to mention nutritional requirements (e.g. a human needs far more calories to live and sustain more complex systems than does a bee). In light of certain experiments that would be unfeasible to perform on humans (e.g. for ethical or financial reasons), however, animal analogue systems are the best way for humans to learn more about not only the natural world, but how we ourselves work.

References American Psychological Association. (2010). Guidelines for Ethical Conduct in the Care and Use of Animals. Retrieved April 20, 2010 from http://www.apa.org/science/leadershi...uidelines.aspx

Apocal. (2006, February 28). Experiments in the Revival of Dead Organisms [Video file]. Retrieved April 20, 2010 from

Public Library of Science (2010, April 6). Bees with an impaired insulin partner gene prefer proteins over carbs. ScienceDaily. Retrieved April 17, 2010, from http://www.sciencedaily.com* /releases/2010/04/100401173720.htm

Wang et al. Down-Regulation of Honey Bee IRS Gene Biases Behavior toward Food Rich in Protein. PLoS Genetics, 2010; 6 (4): e1000896 DOI: 10.1371/journal.pgen.1000896

Author's note I apologize for the YouTube clip in the middle of my references; I can't seem to get rid of the video even if I remove the hyperlink; if you do want to see it, though, enjoy!