Experiment: Mutation in Drosophila Melanogaster Flies.

Introduction

Drosophila melanogaster, also known as the fruit fly, has been a valuable tool in scientific research for over a century. Its short lifespan, easy handling, and ability to produce large quantities of offspring have allowed scientists to study a variety of biological processes, including genetics, development, physiology, and behavior. In addition, the genome of Drosophila has been fully sequenced, which has allowed for a better understanding of molecular biology and the relationship between genes and human diseases. Drosophila melanogaster continues to be a valuable tool for scientific research and has been instrumental in advancing our understanding of biology and genetics.

Why use Drosophila Melanogaster (or fruit fly) in genetic experiments?

D. melanogaster is an ideal organism for experimentation for several reasons. Firstly, it is abundant and easy to capture, and can be easily cultivated in the laboratory. Additionally, it produces a large number of offspring, making it suitable for testing Mendelian ratios. Its biological cycle is completed in 10-11 days at 25°C, and it has only 4 pairs of chromosomes, 3 autosomes and 1 sexual, with sex determination of XX females and XY males. Since its use in 1905, an abundant bibliography has been accumulated. Finally, there are a large number of natural and induced mutants and special strains that allow for careful genetic analysis.

What are the mutations present in Drosophila Melanogaster?

There are several known mutations in Drosophila melanogaster. These are the most common mutations and their characteristics:

• “White-eye” mutation: This mutation is due to a recessive gene on the X chromosome that causes the absence of pigment in the eyes, resulting in white eyes instead of red.
• “Sepia” mutation: This mutation also affects eye color, but instead of resulting in white eyes, it produces dark brown eyes.
• “Vestigial” mutation (short wing): This mutation affects wing development and produces shorter and more wrinkled wings than normal.
• “Bar” mutation: This mutation affects the development of hairs on the fly’s legs and produces shorter and thicker hairs.
• “Antennapedia” mutation: This mutation affects antenna development and produces a transformation of the legs into antennas.
• “Flamingo” mutation: This mutation produces defects in the formation of epithelial cells, resulting in deformed legs.
• “Ubx” mutation: This mutation affects leg development and produces additional or fused legs in different parts of the body.

These are just some of the known mutations in Drosophila melanogaster. There are many other mutations that affect the shape, color, and behavior of fruit flies. Mutations in Drosophila melanogaster have been an important tool in genetic research for decades.

Eye mutations in Drosophila melanogaster.

Drosophila melanogaster is a species commonly used in genetic studies due to its short life cycle and ability to produce large amounts of offspring. In this species, there are several known mutations that affect the appearance of the eyes. Below is a table with some of these mutations and their characteristics:

It is important to note that there are many more mutations that affect the appearance of the eyes in Drosophila melanogaster, and each mutation can have additional effects on the health and behavior of the fly. Additionally, the expression of these mutations may be influenced by additional environmental and genetic factors.

Procedure

1. Collect flies in each house and place them in glass jars containing food (decaying fruit). Cover with cotton or gauze and a rubber band.
2. Bring the jars with the flies to school (always have reserve jars at home). Search for information on fly characteristics on the Internet, print it in color or draw it.
3. Look for information on mutations. Submit partial report.
4. Put the flies to sleep and start noting their characteristics, as well as separating males from females. Note eye color and wing size characteristics.
5. Prepare jars for pairs: at least 5 jars per group.
6. After sterilizing the jar with alcohol, put the food and then introduce the pair of flies. Label the jar with the characteristics, date of assembly, and group name. If changing the food, notify the teacher and/or laboratory assistant.
7. Store the jar in a warm place. Observe every two days. When the eggs appear, remove the pair and wait for the births.
8. Observe the larvae, look at them with a magnifying glass and draw them. Look for information on the larvae on the Internet. Submit partial report.
9. Observe the pupae, describe them and note how many days they are in that stage.
10. Observe the born flies, count and draw one. Separate them into male and female. Count them according to eye color and wing size.
11. Note if there are mutants and separate them. The non-mutants should be reserved separately and classified as “Generation F1”.
12. Extract a new pair from this F1 to obtain the F2 and proceed in the same way in each case.
13. Always consider hygiene, sterilization, food preparation, care when handling, and order in the group for the procedure.
14. Always take notes on observations, stay informed about the zoology of the flies, and apply what was learned in theoretical classes.

Conclusion questions:

• What were the characteristics observed in fruit flies in this experiment and how were these characteristics transmitted from one generation to another?
• How can a fruit fly’s genotype be determined based on its phenotypic characteristics?
• What is the importance of fruit flies in scientific research and how have they been used in genetics and other fields of biology?
• What role do genes play in determining physical and behavioral characteristics in fruit flies and how can these characteristics affect the survival and reproductive success of the flies?
• What are some of the limitations and challenges associated with the use of fruit flies in scientific research and how can they be overcome.

Sources

Here are some sources where it is possible to find simulations or videos about the importance of Drosophila melanogaster in genetics:

1. Interactive Drosophila Melanogaster Simulation: This is an interactive simulation where you can breed fruit flies and observe the results of different crosses. You can find it at: https://phet.colorado.edu/sims/html/drosophila-genetics/latest/drosophila-genetics_en.html
2. Drosophila genetics tutorial: This tutorial is a step-by-step guide to the genetics of Drosophila melanogaster, with explanations and interactive activities. You can find it at: https://www.genetics.org/content/147/3/1189.full
3. The Virtual Fly Lab: This website provides a range of interactive simulations and activities related to Drosophila genetics, including breeding experiments, mapping genes, and observing mutant phenotypes. You can find it at: http://virtualflylab.org/
4. The importance of Drosophila in genetics: This video from the National Human Genome Research Institute explains why Drosophila melanogaster is an important model organism for genetic research, and how its use has contributed to our understanding of genetics. You can find it at: https://www.youtube.com/watch?v=0gZ5oGQ5I5g
5. Fruit Fly Genetics – Drosophila melanogaster: This video from the Dolan DNA Learning Center provides a clear explanation of the use of Drosophila melanogaster in genetics research, and how it has led to important discoveries. You can find it at: https://www.youtube.com/watch?v=v1lr9n1pMvE