Drosophila Melanogaster Case Study

The observed results from the ¬F1 generation were that the phenotypes had to be EeNn x EeNn. The expected results for the F1 generation were also EeNn x EeNn because the P generation phenotypes for the male fruit fly were Ee and were Nn for the female P generation flies. The expected results for the F2 generation were a 9:3:3:1 ratio from the phenotypes NENenEne x NENenEne. The Chi squared value turned out to be 4.14 when the differences between observed and expected results were

Introduction: The intention of this lab was to gain a better understanding of Mendelian genetics and inheritance patterns of the drosophila fruit fly. This was tasked through inspecting phenotypes present in the dihybrid crosses performed on the flies. An experimental virtual fly lab assignment was also used to analyze the inheritance patterns. Specifically, the purpose of our drosophila crosses is to establish which phenotypes are dominant/recessive, if the traits are inherited through autosome or sex chromosomes and whether independent assortment or linkage is responsible for the expressed traits.

The conducted experiment assists in determining an unknown mutant allele found in Drosophila melanogatser. Mutant 489 illustrates a defect in eye pigmentation, which displays a dark brown eye color verses the brick red eyes in wild type flies. Based on the appearance our 489 mutation we've names our mutant rust.

Jack J, DeLotto Y. Effect of Wing Scalloping Mutations on Cut Expression and Sense Organ Differentiation in the Drosophila Wing Margin. Genetics. 1992;131(2):353-363.

When examining the D. Melanogaster mutants in the lab, our group immediately noticed an apparent difference from the wild-type flies. None of the mutants were able to fly. This led us to believe that we were dealing with a wing mutation. Upon further examination, we concluded that it was the overall wing shape that prevented the mutants from flying. The wing shapes among the mutants varied in both size and shape. Some were long, while others were short. The mutant wings could be distinguished into two general classes. One division of the mutant wing was short and stubby, almost a fourth the size of the wild-type wing. The rest of the mutants ranged in wing size and length, however many mutant wings were the same length as the wild-type wings. Although the

The scarlet pigment is made when the enzyme kynurenine hydroxylase that produces a brown pigment is blocked and the brown color isn’t prominent causing the eye to appear as a scarlet color. In the sepia eyed fly it was found that the pigments isosepiapterin and isoxanthopterin were the same as in the wild type; the pigments biopterin, 2-amino-4-hydroxypteridine, sepiapterin, xanthopterin, and xanthommatin were much more than in the wild type; and the pigment drosopterins was much less than in the wild type. The sepia pigment is made when the enzyme PDA synthase that produces a red-orange pigment is blocked so more can go towards the other pigments causing the eye to appear as a sepia pigment. This data supports the original hypothesis that there would be a difference in the pigments present based on which enzymes are changed. The white eyed fly, the brown eyed fly, the rosy eyed fly, the scarlet eyed fly, and the sepia eyed fly all differed from the wild type fly in some way due to the fact of certain enzymes being blocked or changed

There were some sources of error in crossing between certain traits, specifically in determining the genotypes of the organisms being crossed. For example, there was no method of determining whether the wild type flies were homozygous dominant or heterozygous. The method used seemed reliable, but due to the questionable results, it may be more effective to find another

Loss of function (loss of gene expression from the developing wing epithelium) of each of these genes leads to complete loss of wings:

Heterozygotes, which have the wild type phenotype, have normal sight which gives them the advantage of finding a mate and have a better success with attracting a mate with their courtship song (Kyriacou et al, 1978). The male heterozygous Drosophila had a better advantage at mating than the homozygotes, which were the ebony, and therefore we predict there will be more wild type by the end of the experiment.

Introduction Drosphila melanogaster, commonly known as the fruit fly, is an excellent organism for genetics studies because it has simple food requirements, occupies little space, is robust, completes its life cycle in about 12 days at room temperature, produces large numbers of offspring, can be immobilized readily for examination and sorting, and has many types of hereditary variations that can be observed with low-power magnification. The fruit fly has a small number of chromosomes (4 pairs), which are easily located in the large salivary gland cells. As mentioned before, the fruit fly life cycle is complete in about 12 days. First, a fertilized adult female must lay the egg, which leads to the first stage of the fruit fly life cycle, the egg stage.

Prud’homme et al. (2011) demonstrated that the wing specific gene nubbin was expressed in a similar pattern in the helmet formation as in wings and arrived at the conclusion that the treehopper helmet was serially homologous to the T1 wing. In addition the authors speculated that the evolution of the helmet is due to a change in an unknown genetic mechanism downstream of Scr (sex combs reduced), which is part of the hox gene family. Thereby suggesting that the evolution of the treehopper helmet is due to genes that were under repression by hox genes. Moczek (2011) speculated that the tree hoppers evolved a wing like structure through re- emergence of a repressed developmental program of the wing. Clark-Hachtel and Tomoyasu (2016) proposed that the treehopper helmet might be partially homologous to the wings based on the fact that the treehopper helmet and the beetle carinated margin of Tribolium beetle both originate from the T1 tergum and it was shown that the reduction of the repression of Scr lead to formation of wings in the beetle. Conversely Yoshizawa (2012), proposes that the lack of evidence for the Scr mechanism in treehoppers might be due to pleiotropy and

Introduction: The Drosophila project was fundamentally conducted to determine potential regulators of the wingless pathway in Drosophila Melanogaster. All the experiments in this project were used to establish two things. Firstly, the location of the transposon insertion and secondly, the effect the genes near the transposon insertion had on the wingless pathway.

The drosophila melanogaster is the model animal of choice due to the fact that they have a short reproduction time. They are sexually active after only two days of emerging from their casing. They then mate and can lay up to hundreds of eggs which take about a week to hatch. This makes them easy test subjects that way different generations can easily be studied. They are inexpensive and require a simple diet of carbohydrates and proteins. They are about 3mm in size, therefore they can easily be seen without a microscope. Drosophila have about 75% of homologues genes of humans this can cause better understanding of mutations that are found. Due to the fact that Drosophila are insects some aspects of the humans can’t be understood. Drosophila melanogaster is the perfect choice for the specific experiment stated because of the many genes that are present and because they have a short life span it is easy to get many offspring in a short amount of time. The genes can easily be deleted or moved throughout the embryo of the melanogaster. The experiment also calls for visual effects and with the model organism used one could clearly examine the effects. Due to the quick reproduction cycle of the drosophila melanogaster if a mistake is made and the experiment has to start over then one would not have to wait a long time before there is new offspring to experiment on. Drosophila have approximately 17,000 genes. Of these genes are the segmentation genes which are used to

The Beadex gene can go through epistasis which would in this case effect the development of the mutant’s wing. It was discovered that Beadex is a gene that is regulatory by checking for the second site mutations that would enhance the Beadex phenotype or overwhelm the gene. Two genes that are able to perform this action are Chip and apterous, each of which plays a big role in development (Hari 2008). These genes were also discovered independently while scientists were looking for genes that can single handedly alter a wing’s mutation. The Beadex protein is very complex and has two LIM domains which are connected to other

During reproduction, the inherited factors (now called alleles) that determine traits are separated into reproductive cells by a process called meiosis and randomly reunite during