Drosophila Melanogaster Experiment Essay

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.

In most kitchens the small flies that are found are Drosophila Melanogaster also called fruit fly. They are often brought in by ripened tomatoes, grapes and other perishable items from the garden. Drosophila melanogaster is a little two winged insect about 3mm long two winged insect that belongs to the Diptera, the order of the flies. The drosophila egg is about half a millimeter long. Fertilization takes about one day the embryo to develop and hatch into a worm-like larva. The larva eats and grows continuously, after two days as a third in star larva; it moults one more time to form an immobile pupa. Over the next four days, the body is completely remodeled to give the adult winged form, which then hatches from the pupal

A variation among individuals must be present that is inherited and allows some of these individuals to be more successful at survival than others. The theory of its action was first fully expounded by Charles Darwin and if one trait has consistently experienced greater success, then that trait will become more prevalent over time in that population. Jacobs (1961) found that the frequency of ebony (e/e) flies dropped rapidly in the light compared to dark environments. Tan (+/+) males showed a direct advantage in light as compared with dark, thereby allowing relatively greater numbers of the heterozygote (+/e) males and homozygote ebony males to mate in dark conditions. The stabilization of the ebony gene is due to the ebony allele in the heterozygous fly, which increases sexual activity of males. The ebony (e/e) homozygotes have decreased sexual activity as compared with the wild type (+/e). While genetic drift typically behaves differently in each population, the results of natural selection are consistent from population to population.

The following procedure comes from BIOL 2040 Laboratory Manual written by Elizabeth Welsh (Welsh, 2016).

Throughout this experiment a number of random and procedural errors were apparent; these errors could have affected the results of the experiment in a number of ways. One experimental error that occurred during the experiment was that some flies became stuck in the food source and died. The main cause of this was the fact that the fly vials were stood up (vertically) before the flies had fully recovered from the anaesthetic. This could be overcome in future experiments by ensuring that the vials are kept horizontal until all of the flies fully recover from the anaesthetic.

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.

Drosophila melanogaster may just be small little fruit flies that feed on rotten fruit but this little creature happens to be one of the most valuable organisms in understanding genetic research. The D. melanogaster are commonly used in studying genetic traits because they are useful, small and have an extremely short life cycle (6). Our experiment shows precisely how D. melanogaster are used to identify mechanisms of transmission genetics in eukaryotes. Simple parental crosses were done to obtain both F1 and F2 generations. This was done so we could determine if the apterous (a wingless phenotype) and the sepia (dark brown) eye color of the fruit flies follows Mendelian inheritance or not. Our F1 generation displayed all offspring with red-eyes and wings; which follows Mendel’s principles. Our hypothesis is that our experiment will follow the classic inheritance patterns because the sepia traits and the wing traits display a dominant/recessive pattern in the D. melanogaster (4). If our hypothesis is correct, then we predict to see an entire F1 generation of red eyed fruit flies with wings and an F2 generation of 9 normal

Although we did not use this fly as a parent in the F2 cross, we did end up with a completely white fly. When looking at this fly, we were unable to determine if it was a male of a female due to the fact that it had no visible striping pattern or sex combs (colorless). Due to the fact that all the other fly offspring exhibited the predicted phenotypes, we cannot state with certainty that we made in error in the selecting the correct genotypes and phenotypes of the P1 flies. This pigment-less fly is likely the result of a gene in the fly that determines albinism. Albinism is a rare gene in organisms. It is typically inherited via autosomal recessive inheritance, meaning the two parents of this specific albino fly must have also been heterozygous for the albinism trait (SOURCE F). Of course, this is assuming that the colorless fly is a direct result of inheriting two albino alleles from the parents. We also can consider DNA errors, environmental factors, or errors in the initial F1 cross that could have led to this completely white

The fruit fly, Drosophila melanogaster, became an important model organism for the study of human genetics and for the establishment of more biological principles (Roberts 2006). This organism became a good candidate to work with because of its short life cycle, its inexpensiveness, small size, its genetic variability, easily cultured and its ability to produce many offspring. Nichols and Phandey made an important discovery: approximately 75% of disease-causing genes in humans are homologous to genes found in Drosophila melanogaster (Russell and Tickoo). This is an important observation, because it made it possible to discover treatments for human diseases. For example, the fly has a tumor gene homologous to the human LATS1 gene.

Drosophila is an ideal model organism that is largely used for the biological research study for over the centuries. In history, there is much research relevant to Drosophila contribute to the understanding of human towards different fundamental biological phenomena. The first published research paper on Drosophila in 1910, “Sex limited inheritance in Drosophila” was written by Dr. Thomas Hunt Morgan who was known as “father of Drosophila”. The theory of inheritance which was first proposed by Gregor Mendel was proved in the research paper by investigation on mutant fly lines. The research claimed that the genes are the physical basis of heredity that are present within the chromosomes. This made a big step forward to the understanding of modern genetics and it give rise to manipulation of

In this experiment, vestigial flies as well as wild type flies were used to create some diversity as well as test one of our hypotheses. Our hypotheses are as follows; 1) The wild type flies will have a greater relative fitness compared to the vestigial flies based on only sexual selection.  The wild type has a relative fitness of 1 since it has fully functional wings.  Vestigial Winged flies are not as sexually appealing since their wings are not functional and the wing movement is a vital part of their mating ritual.  2) The vestigial fly will have a greater relative fitness when considering both sexual and natural selection. With the presence of

Drosophila melanogaster is an important model organism in biological research and has been prevalent for over one hundred years. Fruit flies are used by researchers because they having many qualities that make them favorable in research including their genetics, size, and reproductive capacity. The goal of the experiment is to test the different genetic mutations and sex linked crosses that each generation of the fruit fly can make. This lab sets up crosses of flies that reproduce in two-week span. The parents for the initial cross in the F1 generation are homozygous recessive white- eyed females and wild type red-eyed males (Shoup). After two weeks, the F1 generation phenotypic ratios change for the F2 offspring. We expect that the

The studies in Drosophila melanogaster have helped scientists to have better understand about genetic and scientifically discover the variety of human diseases from mutations. After observing under 50X magnification, the differences between the female and male unknown mutants 651 are that the shape of male’s pseudopupils are larger than female’s and the volume of bristles and hairs on male’s notum are greater than female. In addition, the larva of wild type is a little larger in length and width than the larva of unknown mutant while the color of mutant’s larva is a bit whiter than wild type’s. Most of the distinguish differences of phenotype between wild type and unknown mutant are found on the thoracic notum, which includes the arrangement,

2. Six Sepias (3 males, 3 females) were added to both vials. Six Wildtypes (3 males, 3 females) were added to both vials. This was done by transferring them while they were FlyNapped. They were topped immediately after with the vial being placed on its side so the flies would not drown in their food when they woke up. These vials contained the parental generation.

A gene is a trait that is passed down from one generation to another and gives an organism its characteristics. In this experiment, there are two different genes that affect whether a fruit fly, or Drosophila melanogaster, is winged or wingless. Most fruit flies have wings, this is the dominant trait. If an organism carries a dominant trait, that trait will always appear in the organism’s offspring. Compared to the number of winged flies, few fruit flies are wingless. Wingless is the recessive trait. If an organism carries a recessive trait and a dominant trait, the recessive trait will not show up in the organism’s physical appearance; however it will still be present in their genes (Mendelian Genetics, Biology). In this experiment, wingless