In this experiment, we are analyzing qualitive data of targeted characteristics of offspring Drosophila of a female Drosophila with a Gal 4 driver and male Drosophila with DNA containing UAS and genome needed for RNAi. If there is a deformation of such targeted characteristics in the offspring, in this experiment the eyes or wings, this indicates a possible disruption of metabolic genes.
When flies are crossed, the expression of a targeted gene can be present in four different ways; it can be expressed only during fly development, only after fly development, both during and after fly development, or neither during nor after fly development. We are interested in finding offspring that express the targeted gene only during development. Of the RNAi
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For this process to begin, the genome of the strand of DNA must form a specific pattern. If a line was draw down the very center of the DNA sequence, every base of the same distance away from the center line must be matching based pairs. To illustrate this concept, a diagram bound to the same rule with ten base pairs would have matching base pairs at numbers 5 and 6, 4 and 7, 3 and 8, 2 and 9, and 1 and 10.
When this pattern occurs, the genome sequence of the RNA derived from the previously described DNA can bind to itself. This creates a bend in the genome, and the transcribed RNA becomes double-stranded. This structure is like that of a virus, and the cell regards it as such. Therefore, just as it would a virus, the cell looks for matching sequences and destroys them. This disallows the gene to be expressed.
Of the flies containing Gal 4, we are utilizing virgin females in this experiment. When Gal 4 is present in a female fly, that fly’s offspring has a disposition to have a phenotype associated with that Gal 4. In this experiment, we are breeding and crossing three different types of Gal 4 females; Gal 4 eya, Gal 4 GMR, and Gal 4
The gall is made of plant tissue but aspects of genetically coded stimulus from the insect makes the gall from the normal plant tissue (Abrahamson, 1989). The gall can be many different sizes in diameter. Survival depends on the gall size, the smaller the galls means that the larvae is vulnerable to parasitoid oviposition, but when the galls are larger they are more likely to be attacked by avian predators (Abrahamson, 1989). Gallmaker enemies can influence the survival of individual gallmakers. The natural enemies of the gallmakers can have a potential effect and alter gallmaker traits for other generations if survivorship varies (Abrahamson, 1989). This study wanted to know three things, how many gallmakers there are as well as how many natural enemies there are, and to what extent of the goldenrod fly mortality was due to insect and bird enemies listed above. They also wanted to know what gall size did these natural enemies prefer and what kind of
In science, these fruit flies can be used to study genes and mutations relatively quickly because of the limited life span. Knowing mating behaviors can help scientists better understand their results and improve their experiment designs to reduce
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:
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.
Examining the Crosses Between Drosophila Fruit Flies Introduction The major topic of this experiment was to examine two different crosses between Drosophila fruit flies and to determine how many flies of each phenotype were produced. Phenotype refers to an individual’s appearance, where as genotype refers to an individual’s genes. The basic law of genetics that was examined in this lab was formulated by a man often times called the “father of genetics,” Gregor Mendel. He determined that individuals have two alternate forms of a gene, referred to as two alleles.
Robert Warren, Lisa Nagy, Jane Selegue, Julie Gates, and Sean Carroll produced this experiment that wanted to examine homeotic gene expression in butterflies. The hypothesis they tested was do homeotic genes have driven morphological change or do the homeotic genes provide a pre-existing plan where insects segment diversity evolved. The genes Antp, Scr, Abd-A, and Ubx were isolated from a cDNA library and were used to explore differences in limb and wing numbers between flies and butterflies. Where Ubx and Abd-A are expressed, the limb and wing numbers arose. They started to wonder if the expression of BX-C genes were different in butterflies (P.Coeni) and fruit flies (drosophila). When they did tests, they saw that conservation of BX-C and ANT-C homeotic gene expression are fundamentally similar and don’t explain the differences in appendages in each species. They looked into embryogenesis, and at 20% of the embryogenesis of butterflies, they saw Abd-A protein and RNA are expressed in the anterior and abdominal segments. High levels of Antp expression are seen in the thorax. Past the 20% mark of embryogenesis, the patterns seen of Abd-A, DII, and Antp expression differed extremely - no DII or Antp were expressed in the abdominal proleg.
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.
What has to happen for a gene to be transcribed? The enzyme RNA polymerase, which makes a new RNA molecule from a DNA template, must attach to the DNA of the gene. It attaches at a spot called the promoter.
strands which make up the letters of a genetic code. In certain regions of a DNA strand
17. Fruit flies normally have eight chromosomes. The diagram below shows the result of meiosis in three fruit flies to produce gametes with the number of chromosomes indicated. The male then mates with both female A and female B to produce three zygotes (1, 2, and 3).
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 F2 punnett square shows that there should not be a female fly that has apterous wing mutation. Our observed experiment showed that female flies are capable of forming in the F2 Generation. Therefore, the mutation is located on autosomal chromosomes. In trial 1, the p value is not significant. This could be due to the fact that the male to female ratio in the F1 generation was unequal. In trial 2, the p value is significant and likely due to chance. The probability error is between 1 % and 5%.
Conclusion for class di-hybrid cross: The p value 0.779 is in the non-significant range in the chi square table. The null hypothesis is therefore correct. Sepia eyes and vestigial wings in the flies is a mutation in the genes that is not linked meaning it is a product of independent assortment.
A chromosome is made up of two identical structures called chromatids. The process of nuclear division is called interphase; each DNA molecule in a nucleus makes an identical copy of itself. Each copy is contained in the chromatid and a characteristic narrow region called the centromere holds the two chromatids together. The centromere can be found anywhere along a chromosome but the position is the characteristic for a particular chromosome. Each Chromatid contains one DNA molecule. DNA is the molecule of inheritance and is made up of a series of genes. The fact that the two DNA molecules in the sister chromatids, and hence their genes, are identical is the key to precise nuclear division.
Secondly the gene has to be cut from its DNA chain. Controlling this process are many restriction endonucleases (restriction enzymes). Each of these enzymes cut DNA at a different base sequence called a recognition sequence. The recognition sequence is 6 base pairs long. The restriction enzymes PstI cuts DNA horizontally and vertically to produce sticky ends.