Fruit Flies Experiment
Bio 111
November 16, 2015
Samuel Bautista
Abstract
Since the turn of the 19th Century, Biology departments have used Drosophila melanogaster (fruit flies) as a way to understand and observe Mendelian Genetics. Since fruit flies share “share 75% of the genes that cause disease with humans” (The Fruit Fly and Genetics). They are also easy to take care of and affordable, which works well for scientist doing the experiment. The two types of fruit flies; Apterus and Drosophila, where use and put in separate vesicle and left to mature for about 8 to 12 hours. Virgin flies must be collected within 15 hours of emergence. After 12 hours flies are then cross breed into a new culture. . This experiment shows many traits where mutations have occurred by observing the fruit fly throughout the whole process.
Introduction
From the mid to the late 1800’s Gregor Johann Mendel was an Augustinian friar who became known as the Father of Genetics. Mendel discovered the basic understanding of genetics through the selective breeding of pea plants. Through Mendel’s research, the discovery of two fundamental principles that gave scientists a basic understanding of how genetic traits are passed down what we call today as Principles of Mendelian Inheritance.
Principle of Mendelian Inheritance 1) Law of Segregation .When any individual produces sex cells (gametes), during cellular division a copy of a gene is separated and as a result each parent will pass on a copy of a gene to each gamete. One allele will be received by one gamete. Law of Independent Assortment. When multiple traits or alleles are being crossed, one pair of traits is being distributed to the gametes. Drosophila melanogaster or fruit flies are a common ...
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Appendix
Male Female Overall Total of Fruit Flies
Culture 1: Zero Flies of both wild type & Apertous Zero Flies of both wild type & Apertous ZERO
Culture 2:
18 Wild types
0 Apertous 15 Wild types
0 Apertous 33
0
Culture 3:
27 Wild types
2 Apertous 19 Wild types
10 Apertous 46
12
Culture 4:
Zero Flies of both wild type & Apertous Zero Flies of both wild type & Apertous ZERO
Culture 5:
67 Wild types
9 Apertous 62 Wild types
7 Apertous 129
16
Total 123 113 236
Amount of Fruit Fly
Shows the amount of fruit flies in each generation and how many female and males of each species are in each generation.
Reference
"The Fruit Fly and Genetics." The Fruit Fly and Genetics. N.p., n.d. Web. 16 Nov. 2015 /
In order to figure out the genes responsible, there are several other factors that must be determined. These factors include the number of genes involved, if each gene is x-linked or autosomal, if the mutant or wild-type allele for each is dominant, and if genes are linked or on different chromosomes. Proposed crosses include reciprocal crosses between the pure-breeding mutants of strains A and B with the wild-type will help determine if the genes or sex-linked or autosomal, in addition to which alleles are dominant (8). Another proposed cross includes complementation crosses between pure-breading mutants from strains A and B to determine if one or two genes are involved (8). Furthermore, testcrosses between F1 progeny and pure-breeding recessive mutants from strains A and B, which will help determine if genes are linked on the chromosome or if they assort independently (8). These proposed crosses are shown in the attached
The idea of the project was to experiment breeding Drosophila Melanogaster (fruit fly) to figure out if certain genes of that species were sex linked or not (autosomal). A mono-hybrid cross and di-hybrid cross was performed. For the mono-hybrid cross, white eyed female and red eyed male were placed in one vial for them to reproduce. For the di-hybrid cross, red eyed and normal winged flies and sepia eyed and vestigial winged flies were placed in their vial to reproduce. In the mono-hybrid cross the results expected were within a 1:1:1:1 ratio. Expected results similar to the expected desired null hypothesis proposed with what the F1 parental generation breeds. The potential results would have had to have been within the ratios of 9:3:3:1. The results were clear and allowed the null hypothesis to be correct. The white eyed gene in the fruit flies is sex linked. Sepia eyes and vestigial wings are not sex linked and are examples of independent assortment.
Introduction: The purpose of this laboratory activity is to investigate the Hardy-Weinberg Law of Equilibrium using the fruit fly Drosophila melanogaster. According to the Hardy-Weinberg Law of equilibrium, allele frequencies should remain the same in large populations that do not experience gene flow, mutations, nonrandom mating, and natural or artificial selection. We will be studying the alleles that determine wing shape, either normal (wild type) wings or vestigial wings.
In this experiment, Mendelain Models are observed. The purpose of the experiment is to understand how traits are passed from one generation to the other as well as understanding the difference between sex linked and autosomal genes. One particular trait that is observed in this experiment is when a fly is lacking wings, also known as an apterous mutation. In this experiment, we will determine whether this mutation is carried on an autosomal chromosome or on a sex chromosome. The data for this experiment will be determined statistically with the aid of a chi-square. If the trait is autosomal, then it will be able to be passed to the next generation on an autosomal chromosome, meaning that there should be an equal amount of male and
The fruit fly, or the Drosophila melanogaster, was used in this experiment to study patterns of inheritance. It only takes a fruit fly 14 days to develop from an egg to an adult and then 12 hours before they become reproductive, so these factors made the fruit fly a good species to study, because we had enough time to do crosses. We were investigating the patterns of inheritance in the eye color and the wings. The wild type flies had red eyes and full wings, while the mutant phenotype had brown eyes and no wings. We also had to study the sexes of the flies. The male flies had darker abdominal tips and sex combs on both of their forearms. For the results, my group had predicted as follows:
An individual can be homozygous dominant (two dominant alleles, AA), homozygous recessive (two recessive alleles, aa), or heterozygous (one dominant and one recessive allele, Aa). There were two particular crosses that took place in this experiment. The first cross-performed was Ebony Bodies versus Vestigle Wings, where Long wings are dominant over short wings and normal bodies are dominant over black bodies. The other cross that was performed was White versus Wild where red eyes in fruit flies are dominant over white eyes. The purpose of the first experiment, Ebony vs. Vestigle was to see how many of the offspring had normal bodies and normal wings, normal bodies and vestigle wings, ebony bodies and normal wings, and ebony body and vestigle wings.
We then allowed the larvae to hatch, and counted and recorded the total number of flies, the phenotype, and the sex. After taking down all this information this would allow us to perform a F1 cross, we made sure to examine the flies carefully since we needed virgin flies. We prepared a new vial with the a 1:1 ratio of medium and water. After recording the data of the F1 generation, and picking out the virgin flies for the crossing, and we killed of the rest of the flies using the oil method. After some time passed the F1 generation had larva in the vial. Once we noticed the larva we had to put the flies to sleep and collect the data. We then had to prepare another two new vials and medium and water. Carefully observing the flies and picking out three males and three female virgin flies to place into the new vial. Than killing of the other flies. After about a week we had the F2 generation. This was the most important generation, it was what we were looking for to allow us to observe and compare our experiment to Mendel’s experiment. We were looking for a 9:3:3:1 ratio with our flies. Using a basic Punnett square table and the crossing that we had accomplished our results should have looked like the following Punnett square.
Multiple allele is when more that one allele is being crossed and all of the traits are being crossed together. Sex linked inheritance is when the gene for a certain trait is carried on either the X or Y chromosomes for the parent. The goal of this lab is to better understand genetics. The guiding question is, Which model of inheritance best explains how a specific trait is inherited in fruit flies? In first population, the model of inheritance was dominant-recessive and the wild body type is dominant and the aristapedia body type is recessive.In the second population, the model of inheritance is incomplete dominance because the mellow trait crossed with the hyper trait combines to make the spontaneous trait. In the third population, the model of inheritance was sex linked recessive to the yellow colored trait on the X chromosome. In the fourth population, the model of inheritance was a multiple allele autosomal cross for the different traits.
Gregor Mendel was born into a German family, as a young man Mendel worked as a gardener and studied beekeeping. In his later life Mendel gained his fame as the founder of the modern science of genetics. The research that was his claim to fame was his pea plant experiment. Mendel looked at seven different characteristics of the pea plants. For example with seed colors when he bred a yellow pea and green pea together their offspring plant was always yellow. Though, in the next generation of plants, the green peas reemerged at a 1:3 ratio. To explain what he had discovered, Mendel put together the terms “recessive” and “dominant” in reference to specific traits. Such as, in the previous example the green peas were recessive and the yellow peas
Mendel wrote that genes are passed from parents to their children and can produce the same physical characteristics as the parents.
The exercise involved a series of ‘mating’ events resulting in 6 generations. Each mating event produced offspring with ‘possible’ newly inherited traits. The idea of ‘chance’ was included through simple coin tosses. Also, ideas of selection and mutations were introduced into the ‘gene pool’, which presented a deeper and more clear understanding of Mendelian inheritance and the Hardy-Weinberg equilibrium. Upon reaching the third generation, A B1 mutant allele was introduced to the blue locus-influencing fin shape and a G1 mutant allele was introduced to the green locus-influencing Mouth
The Queensland fruit fly is significant pest for many states and attacks a wide range of plants which decreases the production and making fruits inedible. This has large consequences for the local and international fruit and vegetable trade. The most common way that the Queensland fruit fly spread to new areas is by being carried interstate by infested fruit and vegetables. This fruit fly has a large potential to infest a large range of crops, garden plants, native plants and weeds. The female Queensland fruit fly is the main pest as it lays eggs inside of many fruits. The larvae then hatch of the fruit and eat the inside of the fruit which in turn destroys the fruit and deems it inedible. The larvae then shelter themselves in soil until they are fully formed flies. They then repeat the cycle and breed into fruits.
When Mendel’s research was rediscovered in the early 20th century, many geneticists believed that his laws of inheritance conflicted with Darwin’s theory of natural selection.
Genetic testing has become very popular as technology has improved, and has opened many doors in the scientific community. Genetic testing first started in 1866 by a scientist known as, Gregor Mendel, when he published his work on pea plants. The rest was history after his eyes opening experiments on pea plants. However, like any other scientific discovery, it bought conflicts which caused major controversies and a large population disagreed with the concept of playing with the genetic codes of human beings. Playing God was the main argument that people argument that people had against genetics. genetic testing became one of the major conflicts conflicts to talk about, due to the fact that parents could now have the option of deciding if they
Gregor Mendel, born as Johann Mendel, is considered to be one of the most significant historic scientist of all time. He was an Austrian scientist and monk and is best known as the “Father of Modern Genetics.” He founded the science of genetics and discovered many things that dealt with heredity that still applies to our world today. He is remembered for paving the way for scientists and future generations to come. Unfortunately, Mendel’s work went unnoticed until 16 years after his death and 34 years after he published his research. Though Mendel lay covered in his grave, his work would eventually be uncovered. Although Mendel was not there to see it,