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Niederecker, Kirkpatrick, Attarian Final
- 1. The Effect of Caffeine on the Resistance to Heat in Drosophila melanogaster Richard Niederecker, Kara Kirkpatrick, Samyar Attarian Department of Biology Sciences Saddleback College 28000 Marguerite Parkway, Mission Viejo, CA 92692
- 2. Introduction • Drosophila melanogaster – Fruit fly • Research benefits: – Short Lifespan – Distinct Developmental stages – Similarities to humans • Genome • Heat shock response Lanneau, D., M. Brunet, E. Frisan, E. Solary, M. Fontenay, and C. Garrido. 2008. "Heat shock proteins: essential proteins for apoptosis regulation". Journal of Cellular and Molecular Medicine. 12 (3): 743-761.
- 3. Heat Shock Proteins (HSPs) • Historically drosophila cells have been used to study heat shock proteins • Protective function – Renature proteins • Dependent Chaperone proteins – ATP Example of Heat Shock Protein Tissieres, A., Mitchell, H. K., and Tracy, U. (1974) Heat Shock Proteins: from Bacteria to Man, Cold Spring Proteins: from Bacteria to Man, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY. J. Mol. Bio. pg. 84, 389 Beissinger, M., & Buchner, J. (1998). How chaperones fold proteins. Biol Chem, 379(3):245-59. http://www.ncbi.nlm.nih.gov/pubmed/9563819. Image by Jawahar Swaminathan and MSD staff at the European Bioinformatics Institute - http://www.ebi.ac.uk/pdbe-srv/view/images/entry/3hsc600.png, displayed on http://www.ebi.ac.uk/pdbe-srv/view/entry/3hsc/summary
- 4. Heat Shock Factors (HSFs) • Active HSFs bind to DNA to stimulate production of HSPs • Monomer to Trimer • Trimer- active form • Trimer binds to DNA Liou, S. (2010). The Heat-Shock Response. Miscellaneous Drugs. Huntington's Outreach Project for Education, at Sanford. Web. <http://web.stanford.edu/group/hopes/cgi-bin/hopes_test/the-heat-shock-response/>.
- 5. Inducers Normal Cell Conditions (low concentration HSPs) • Embryonic development • Hormonal stimulation • Cell differentiation • Cell cycle – Cancer research External Stressors (higher concentration HSPs) • Oxidants • Heavy metals • Infectious diseases • Heat • Caffeine • The Effect of Heat and Caffeine on the Development of Fruit Flies (Drosophila melanogaster) by Shiffman and Soliman (2014) Shiffman, B. & Soliman, K. (2014). The Effect of Heat and Caffeine on the Development of Fruit Flies (Drosophila melanogaster). Department of Biological Sciences Saddleback College.
- 6. Hypothesis Drosophila melanogaster consumption of caffeine will induce the production of HSPs, extending the lifespan of the flies in heat compared to heat alone.
- 7. Methods and Materials • 3 colonies – 120 flies each – Control and test groups • Control groups standard medium • Test groups caffeinated medium • Incubated at 32C • Medium production
- 8. Methods and Materials • Two analyses – Pupae (1st colony) – Larvae (2nd and 3rd colonies) • Extended caffeine exposure • Incubated for full lifespan • Medium rehydrated frequently – Increased caffeine concentration – Dehydration of flies
- 9. One-tailed unpaired t-test p = 0.0047 0 1 2 3 4 5 6 7 8 9 10 Caffeinated Non-caffeinated Lifespan(days) Fly Groups Pupa to Adult Lifespan
- 10. 0 1 2 3 4 5 6 Caffeinated Non-caffeinated LifeSpan(days) Fly Groups Larva to Pupa Lifespan One-tailed unpaired t-test p = 1.45 x 10-13
- 11. Discussion and Conclusion • Hypothesis rejected for all colonies • Caffeine and heat are independent stressors • Caffeine toxicity and heat • Conditioning Muller, P. & Vernikos-Danellis , J. (1969). Effect of Environmental Temperature on the Toxicity of Caffeine and Dextroamphetamine in Mice. The Journal of Pharmacology and Experimental Therapeutics. Vol. 171 no 1 pg. 153-158 Krebs, R. A., & Loeschcke, V. (1994). Costs and Benefits of Activation of the Heat-Shock Response in Drosophila melanogaster. Functional Ecology, 8(6), 730–737. http://doi.org/10.2307/2390232
Hinweis der Redaktion
- (Sam) -Drosophila melanogaster is a species of fruit fly which produces the heat shock proteins as a response to stressful situations. -The enhanced synthesis of a few proteins immediately after subjecting cells to a stress such as heat shock was first reported in drosophila cells in 1974 -Heat shock proteins are chaperone proteins that renature denatured proteins. Stressors such as heat, oxidants, heavy metals and bacterial and viral infections are inducers of HSFS that stimulate the production of HSPs. -Last year Benjamin Shiffman, Kareem Soliman found that more flies developed when given caffeine under heat than under heat alone
- By Jawahar Swaminathan and MSD staff at the European Bioinformatics Institute - http://www.ebi.ac.uk/pdbe-srv/view/images/entry/3hsc600.png, displayed on http://www.ebi.ac.uk/pdbe-srv/view/entry/3hsc/summary, Public Domain, https://commons.wikimedia.org/w/index.php?curid=6202710
- The Drosophila melanogaster consumption of caffeine will induce the production of HSPs, extending the lifespan of the flies in heat compared to heat alone.
- (Kara): -flies were provided by saddleback biology department -Three colonies of flies were bred, each consisting of 120 flies. Each colony was broken up into two groups: a control and a test group. -Testing on the first colony began at the pupal stage -The second and third colony testing commenced at the larval stage for extended caffeine exposure -After being placed into the fly culture tubes, all flies were placed into the incubator at 32C -The control group was given non-caffeinated medium, or food, which was produced using equal parts of dehydrated medium and water, and the test group was given caffeinated medium, which was made using a 1% caffeine solution in place of water --Because of the heated conditions, the medium was rehydrated as frequently as possible to prevent an increased concentration of caffeine in the medium and dehydration of the flies
- (Kara) -A one-tailed, unpaired t-test was utilized to compare the average lifespans of caffeinated and non-caffeinated fruit flies -First colony found that caffeinated flies had a significantly shorter life span compared to the non-caffeinated. -Caffeinated flies had an average lifespan of nearly seven days; non-caffeinated flies had an average lifespan of about eight-and-a-half days -However, more than twice as many caffeinated pupae developed into flies than non-caffeinated pupae, which agrees with the previous research by Shiffman and Soliman.
- (Kara) -The second and third colony caffeinated flies also had a significantly shorter lifespan compared to the non-caffeinated. -Caffeinated flies had an average lifespan of two-and-a-half days, while non-caffeinated flies had an average lifespan of nearly five days. - More noncaffeinated fruit flies developed into pupa than caffeinated did
- (Richie) -Based on our results, the hypothesis that lifespan of flies given caffeine, under heated conditions, would increased compared to that of heat alone was rejected. -The data shows that lifespan was significantly reduced in caffeinated flies. -This shows that caffeine and heat are independent stressors of one another when combined and lifespan of the flies is decrease - Muller and Vernikos-Danellis have shown that caffeine's toxicity increases in elevated temperatures of 30 deg. Celsius. This combined with the increase in concentration of caffeine, due to dehydration of the medium could explain the decrease in lifespan of the text group. -Medium in the 2nd and 3rd colonies began to turn brown on the surface after a couple days in the incubator. -The effect of these adverse conditions on the lifespan of the flies is unknown, but it may have impacted the development and lifespan of the flies -Although caffeine increases the likely hood for development in fruit flies are study shows that caffeine does not increase the lifespan under heat
- Thank you Dr. Huntley for providing us with your students’ previous research and helping with the fly cultures. Thank you professor Teh for your guidance throughout our experiment and helping with the fly cultures. We would like to thank Dr. Huntley and professor The for their guidance throughout our experiment