The fruit fly was used because they reproduce quickly, which allowed for us to see exactly what the outcomes of each cross were and the phenotypes were easily distinguishable. Crossing flies American embryologist Thomas Hunt Morgan is considered the founding father of Drosophila research, and arguably the father of genetics? For example: Bar or B, Recessive mutations are written with a lower case letter: Step 5: Observing and counting the F2 generation. Place the mutant gene on either chromosome. 1. By using Drosophila, students will: Cooked media can be stored in a refrigerator for several weeks. Dump anesthetized flies directly into the soapy water or mineral oil where they drown. Simply place the flies back into the culture vial when finished. (RRww x rrWW). Hereditary information is located in genes. It is strongly suggested that you obtain extra virgins in case a mistake is made in identification or the fly dies before mating and egg lying can occur. [Obtain] 100 + offspring = F 1 4-6 males x 4-6 females = P 2 [allow 2 weeks] [Obtain] 100 + offspring = F 2 The first vial is called the P 1F 1 vial and the second is a P 2F 2 vial. When setting up crosses, a 3:1 ratio of virgin females to males is ideal. Go to the website and click launch. Take out 5 to 6 females that you will be breeding. This guide is adapted from the University of Arizona Department of Biochemistry and Molecular Biophysics General Biology Program for Science Teachers: Drosophila Melanogaster and Mendelian Genetics, by Pete Geiger. Cross 2: Morgan then allowed males and females of F 1 generation to mate and produce F2 generation. X chromosome; chromosome II; chromosome III; chromosome IV, Dominant mutations are written with a capital letter: Understand Mendelian genetics and inheritance of traits Communicate and defend a scientific argument. There are a variety of types of food available for the flies; some require cooking and others are bought already prepared and dehydrated. It is possible to maximize the number of virgins in a morning collection by using temperature cycling. Losing cultures is the exception rather than the rule, and as long as students re-culture their flies on a regular basis and no mass contamination occurs, flies can be maintained for decades. Finally, after finishing our experiment, the Drosophila is discarded in a soup water or mineral oil, except the ones we need for the further crosses which we have to put on dry surface in the culture bottle before they come into contact with the moist medium. Visual method on the tube . As soon as you see pupae, transfer the parent (P) generation to the knockout vial, use Fly-Nap, and dispose of them in soapy water. ), enough time to quickly take the plug off the vial, invert it into the funnel, and gently tamp, together, the two vials to force flies down into the new vial. 1. Of these two choices, cooling is the simplest, requiring only a freezer, ice and petri dishes. Virgin females can lay eggs, but they will be sterile. It is a small fly, and one could question why so much time and effort have been directed to this organism. 2. Using the magnifying glass, try to observe fruit flies and see if you can identify the males and females. The FOA is an interactive evolutionary method with two particular idealized search processes based on the foraging characteristics of the fruit flies: locate the food source through smelling and fly towards the corresponding location (i.e., smell-based search process), and fly towards the food source up close using sensitive vision (i.e., vision-based search process). Pictures of virgin males and females: A newly eclosed female. Purchase and gather all your materials. At this time Gregor Mendel’s work on inheritance?had been rediscovered, but scientists still had a very limited understanding about how inheritance worked. There are a variety of laboratory exercises one could purchase, although the necessity to do so is questionable. Jessica Olivares 11/22/2014 Bio 3103 Fly lab report Fruit Fly Report Hypothesis In setting up the fruit fly experiment the predicted mutant phenotypes were to be compared in the observed F1 generation and F2 generation. If resourceful, one can use the CO2 emitted from Alka-Seltzer tablets to anesthetize flies for short periods of time. Species: melanogaster (“dark gut”) If your media is white, look for the small black area (the mouth hooks) at the head of the larvae. Remove the food, wash well, then sterilize by autoclaving (for 20 minutes at 121°C and 15 psi; if containers are plastic, be sure they can be autoclaved) or washing in a 10% chlorine bleach solution. Fruit Fly Genetics Lab. Each fly was harnessed in a small, plastic tube (3.5 cm long) with its forelegs and head extending from a cut, narrow end (0.4 cm o.d.) FlyStuff.com, A division of Genesee Scientific Glass is effective, however if dropped a student could lose 2 weeks of data in a single spill. Some dried premixed media is blue to help identify larvae however this is not a necessity and with a little patience and practice, larvae are easily seen. Organisms require a set of instructions for specifying traits (heredity) Life cycle of Drosophila melanogaster Once you've gotten finished counting the F1 generation, it's time to wait for them to breed with each other and produce the F2 generation. Hi, I'm Thomas Hunt Morgan. Ventral view of a male (top) and female (bottom). … We also studied mutations, which are the changing of an organism's genes and DNA sequence which makes the organism different than that of … The surface should be moist with a shiny appearance and there should be no spaces in the media. Put the foam rubber plug into the top of the vial. Get a plastic vial, powdered media, water, 5 grains of yeast, some orange screen, and a foam plug. The above cycle is for a temperature of about 22°C (72°F). It is about the size of President Roosevelt’s nose on a dime, but despite its small size, the fly is packed with Pictures of males and females. Take equal amounts of powdered media and water and mix in the bottom of the vial. B) An alternative way is to put the flies in the freezer for about 8 minutes. Cooked media The Mediterranean fruit fly (also referred as medfly) offers a unique opportunity for studying starvation. The problem with fruit flies is that they fly! Flies may be added minutes after media has been hydrated. Flies have a short generation time (10-12 days) and do well at room temperature. There are no long-lasting side effects to this method, although flies left in the refrigerator too long may not recover. Remove adults once it has been established that enough larvae are present (typically 7-8 days after the cross) since you may not be able to distinguish parents from the F1 generation. A dihybrid cross was carried out between the Dump Sepia Mutant male and the wild type female Drosophilia melanogaster also known as the fruit fly. Step 1: Setting up a culture for your flies. Mutagenesis. Watch the video above to learn how to make a simple homemade fly trap using a plastic bottle. When a considerable amount of the pupae have hatched, transfer them to the knockout vial and use Fly-Nap. Domain: Eukarya begins in the early years of the 1900s. Name : _____ Genetics of Organisms: Fruit Fly Lab Procedure: Monohybrid Cross 1. Genotype – The genes that an organism possesses. Simply place the flies back into the culture vial when finished. He was the first to discover sex-linkage and genetic recombination, which placed the small fly in the forefront of genetic research. Each female can lay 50-70 eggs per day. There are a variety of plugs available from soft cotton to foam plugs. This is, of course, much quicker and easier than preparing cooked media, so much so that students can fill their own vials with media. Ether is flammable, has a strong odor and will kill flies if they are over-etherized (and can anesthetize younger students!). Classification The first generation (F1) were all wild-eyed and wild-winged, and were all heterozygous with the genotype RrWw. simple introduction to Drosophila genetics, Genetics on the Fly: A Primer on the Drosophila Model System, Taking Stock of the Drosophila Research Ecosystem. However, it is always a good idea to double check using a stereo microscope. Teachers should use fruit flies for high school genetic studies for several reasons: The Construction Kit has two modes: Student Mode - Construct homozygous flies with a mutation in up to 9 fly characteristics. Virgin female showing the meconium (arrow).The meconium is a dark green area and is the remains of larval food. The coloration of the abdomen is the easiest to recognize. Get a plastic vial, powdered media, water, 5 grains of yeast, some orange screen, and a foam plug. Place your prepared culture horizontally and brush the flies with a pun brush into it. A bottle (beaker, or screw-capped jar) filled with ethanol or isopropanol can also be used as a morgue. Other great web resources: Gerard Manning wrote a simple introduction to Drosophila genetics. Prepare the banana medium to feed the fruit flies. This time around, you are going to have to do more counting than before. If there is a desire to maintain stock cultures for a long period of time, or to reuse bottles and vials it is important completely clean and sterilize them. Repeat this with the flies from the male/female vial. Taking Stock of the Drosophila Research Ecosystem by David Bilder and Kenneth D. Irvine (2017). Thse eggs will hatch and larvae will emerge. There was following progeny in The next day, add yeast and plugs. Materials-vials, fruit flies, fruit fly food, plugs, FlyNap (anesthetic), nets, microscopes, paint brushes, probes, freezer. 4. Virgins fruit flies are physically distinctive from mature adults, making it easy to obtain virgin males and females for genetic crosses. F1 is the first offspring generation. **End of Note** Sexing flies This is not long after eclosure; after 4+ hours it becomes more difficult to tell the difference between the two.Note the meconium on the virgin female. Time we got to know the little pest Place in a fresh culture vial and wait 2-3 days look for larvae. Genetics on the Fly: A Primer on the Drosophila Model System by Karen G. Hales et al (2015). The genetics of Drosophila are well documented and several public-domain web sites feature the complete annotated genome. Drosophila melanogaster exhibits complete metamorphism, meaning the life cycle includes an egg, larval (worm-like) form, pupa and finally emergence (eclosure) as a flying adult. Once you have completed all of your counting, you should be able to determine if the trait you were observing was sex-linked or not. Dispose of the remaining flies in soapy water. After the eggs hatch, small larvae should be visible in the growing medium. It all started when we found our first useful fruit fly mutation. The purpose of our fruit fly experiment was to learn about genetics which is the study of DNA, genes and traits. When directly involved, students gain proficiency and a greater understanding of the flies requirements and behavior. Carbon dioxide works very well, keeping flies immobile for long periods of time with no side effects, however CO2 mats (blocks) are expensive and a CO2 source (usually a bottle) and delivery system (vials and clamps) are necessary, increasing the costs. Experiment Overview Determine fruit fly behavior and preferences for certain environmental factors over others by giving them options within a choice chamber. Each has its strengths and weaknesses. This is not as much fun but you won’t have any flies flying around the classroom. 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