Fruit Fly Essay Example for Free

Fruit Fly Essay This experiment focuses on the effects water bath temperatures have on D. melanogaster entering and recovering an anoxic coma. It was found that there was an indirect relationship between the amount of time it took D. melanogaster to enter and recover from an anoxic coma and the temperature of the water bath. D. melanogaster was able to enter and recover from the anoxia coma quicker when they were drowned in a cold water bath condition when comparing these results to the warm water bath condition results. These results support other research findings that investigated the effects of the water bath temperatures. Also other mechanisms that aid D. melanogaster in being able to successfully survive an anoxia coma were researched and discussed while connecting them to current research on human patients with pulmonary diseases. Many animals have developed mechanisms that allow them to sustain anoxia comas for extended periods of time with little to no physiological consequences. This experiment is designed to test the amount of time it takes Drosophila melanogaster to enter and recover from an anoxia coma at different water bath temperatures. The purpose is to deduce the effects temperature has on the organism’s ability to enter and survive the anoxia coma, and generalize what body changes allow D. melanogaster to accomplish this feat. The results are then extrapolated to include how current research is using this information to reduce the amount of anoxia related stress humans with pulmonary diseases experience. Methods Each condition was tested with a separate single group of D. melanogaster (cold bath 8 flies and warm bath – 11 flies), and all of the flies used were approximately 1-9 day old males. Each group of D. melanogaster was held in a container that provided adequate nutrients prior to the experiment, and then transferred to a drowning container that held no nutrients. One group of D. melanogaster was put into a cold water bath (~3? C) whereas the other group of flies was put into a room temperature bath (~24. 5? C). The amount of time it took for the D. elanogaster to stop moving for each condition was recorded as well as the amount of time it took for the last D. melanogaster to stop moving. Once all movement ceased, the D. melanogasters were left submerged for one hour. Afterwards they were removed from the drowning chambers, and carefully transferred from the drowning chamber to a plastic vial with a cotton stopper using a paint brush. Each vial was tapped for one minute, with the cotton stopper at the bottom, prior to recording the flies’ recovery time in order to help dry off the flies. After the initial minute, the time it took for the first and last D. melanogaster to recover (when they started to walk around, not merely flapping their wings) was recorded, and the amount of viable flies at the end of the experiment was also determined. Results The results show that it took considerable more time for the D. melanogaster to recover from the anoxia coma than it took for them to enter the anoxia coma. The average failure time for both conditions was 124. 75 seconds whereas the average recovery time for both conditions was 690. 75 seconds. Also, the temperature of the water bath seems to have a considerable effect on the amount of time it takes for the flies to enter and recover from the anoxia coma. It took the D. melanogasters that were drowned in the cold water bath an average of 22 seconds to enter the anoxia coma, but an average of 244. 5 seconds to recover from the anoxia coma. This same pattern is seen in the D. melanogaster that were drowned in the warm water bath with an average of 227. 5 seconds to enter the anoxia coma, and an average of 1,137 seconds to recover from the anoxia coma. The Q10 value determines how a change of 10? C can increase the rate of chemical processes in an organism, and was calculated for both the failure and recovery conditions of this experiment. The Q10 value provides information about how an organism’s metabolism is affected by the temperature of its environment. It was found that the flies had a failure Q10 value of 2. 964 whereas the recovery Q10 value was 2. 044. Figure 1: This shows the average amount of time it took for D. melanogaster to stop moving and enter into a coma as a result of being drowned in the water bath. Figure 2: This shows the average amount of time it took for D. melanogaster to start walking/crawling around again after being removed from the water bath. Discussion An exothermic organism’s metabolism exhibits a direct relationship with the temperature of its environment. This means that as the temperature of the organism’s environment decreases the rate of its metabolic pathways also decreases. As an exothermic organism, D. melanogaster shows that it is easier to shut down and enter an anoxic coma when in a colder environment as compared to being in a warmer environment. This shows that when in a cold water bath more mechanisms are working together to aid the organism in entering the anoxic coma. D. melanogaster also showed that is takes significantly more time to recover from an anoxic coma than it takes to enter one regardless of the water bath temperatures. This delay could be a result of the organism recreating its supply of the metabolites it requires to restore the sodium/potassium channels and enzymes needed for the metabolic pathways which are extremely important in providing movement in D. elanogaster. When leaving an anoxic coma D. melanogaster also has to prevent reactive oxygen stress while reoxygenating after anoxia. Milton (2007) showed that T. scripta have 5 potential sites for this type of prevention: up-regulation of protective pathways, increasing antioxidants and decreasing production after reperfusion, and repair, protection, and neurogenesis after the oxidation of proteins, lipids, DNA, and RNA. CO2 and N2 concentrations are known to also affect the recovery time. According to Nilson (2006), since â€Å"chill comas, CO2, [and N2] act directly on the transmission of neuronal signals† it comes as no surprise that recovery times increase with an increase of CO2 and N2 exposure. Also Vigne (2009) showed that â€Å"strong dietary restrictions that are close to starvation conditions† can reduce the amount of stress experienced from anoxia recovery. Many organisms are able enter anoxic comas in order to conserve their energy and survive extreme conditions for long periods. Haddad (2006) has shown that D. melanogaster can sustain an anoxia coma for up to 5 hours, and T. cripta have been known to survive 2 days of anoxia with less than 3% cell death upon reoxygenation (Milton, 2007). The human brain fails miserably in comparison which will die within 10 minutes of a decreased oxygen supply, since humans do not have mechanisms that allow them to freely enter anoxic comas or effectively deal with the stresses it causes on the body. The study of the mechanisms that allow other organisms to be anoxia tolerant can be used to understand the effects of some human conditions, and develop methods that counter their effect. D. elanogaster has been used in numerous research studies because they â€Å"provide a better model to study non—cell-autonomous effects† (Azad, 2009). In humans, anoxia is specifically associated with pulmonary diseases such as congenital heart diseases with right to left shunts. Present research is focusing on the effects trehalose, a glucose dimer, has with preventing, or reducing, anoxia related stresses that patients with pulmonary diseases experience. According Azad (2009), transfecting mammalian cells with Drosophila tps 1 gene prot ects them from anoxia related injury.