During the Mendel's rule in 1900, Drosophila melanogaster became a favorite model organism for genetics research. The life cycle of the fruit flies or Drosophila melanogaster, consists of the egg-larva-pupa-adult (male and female). The chromosomes are detailed structurally in comparison to the other normal chromosomes. The chromosomes also have the capacity to show during interphase when normal chromosomes are invisible. The main objective of this experiment is to oversee setup of reciprocal crosses with pure-breeding males and virgin females in relation to the application of Drosophila melanogaster.
Following the rediscovery of the Mendel's rule in 1900, Drosophila melanogaster became a favorite model organism for genetics research. The model (fruit fly) enhanced its popularity among the genetic researchers because of several reasons. One of the essential reasons for its popularity is because of the essence of small flies with increased rearing abilities within the context of the laboratories. This is essential for realization of the goals and objectives of the researchers in the execution of the experiments. The fruit flies also have a short life cycle. This is an indication that adult flies can be obtained every two weeks thus effective for the execution of genetic research exercises (Capy et al., 2006).
The life cycle of the fruit flies or Drosophila melanogaster, consists of the egg-larva-pupa-adult (male and female). Another essence of popularity for this model in the context of genetic research is that the fruit flies or Drosophila melanogaster are fecund. This is based on the capacity of the female to lay hundred of fertilized eggs in the course of the brief life span (Capy et al., 2006). The resulting population is essential for execution of easy and reliable statistical analysis during the execution of the experiment.
Another aspect of popularity is the concept of the giant chromosomes within the salivary glands of the mature larvae. The chromosomes are detailed structurally in comparison to the other normal chromosomes. The chromosomes also have the capacity to show during interphase when normal chromosomes are invisible. The embryo also grows outside the body thus facilitating effective study at each stage of development. There is also the possibility of targeting mutations in relation to specific genes. The genome is relatively small thus essential for execution of a reliable and credible statistical analysis (Capy et al., 2006).
Overview of the Experiment
The main objective of this experiment is to oversee setup of reciprocal crosses with pure-breeding males and virgin females in relation to the application of Drosophila melanogaster. The project focuses on the application of a pair of reciprocal crosses in the form of monohybrid and di-hybrid crosses. The experiment seeks to adopt wild-type flies and flies with white eyes, yellow bodies, or abnormal antennae to facilitate the goals and objectives of the concept of monohybrid crosses. In this cross, the focus will include mutant females and wild-type males while the other will be the opposite of the initial cross. The focus of this group is on the antennapenia cross of wild type (male antennapedia x female wt & male wt female antennapedia).
Materials & Methods
In the execution of this research, the fruit flies were essential to facilitate the goals and objectives of the process. The execution of the research focused on an outlined procedure in order to achieve the desired outcome. The first aspect was the need to prepare fresh bottles for the crosses during the experiment. This required acquisition of two clean milk bottles for the purposes of each cross. Each bottle was to contain approximately 30 ml of instant Drosophila medium flakes (Carolina Biologicals). It was also essential to measure 30 ml of ddH2O. The next step was to swirl the water and media gently to avoid stickup of the components on the sides of the bottle. Following gentle swirling of the medium, few grains were placed on top of the mixture.
An opportunity of approximately five minutes was essential for the medium to setup. The bottles were to contain the sex and phenotype of the flies applicable in the experiment plus the name and date of the exercise. The next step was the collection of appropriate virgin vials with the aim of acquiring virgin females for the execution of the research. There was also the possibility of isolating the males from the stock bottles of non-virgin flies for the purposes of this experiment. In anesthetizing the flies, it was essential to apply FlyNap in the form of 1-2 minutes (one wand) for the small vials and 2 wands for the larger bottles during the experiment. In order to achieve the desired objectives or outcomes, it is essential to monitor the process of anesthetizing with the aim of preventing over-anesthetizing of the flies. The next step was to drop the flies on the white card with the aim of verifying the sex and phenotype prior to setting up of the crosses for the experiment. The experiment adopted and implemented approximately ten virgin females and ten males for the achievement of the main objective in relation to genetic crosses.
A+ female *** male
A female ***+ male
46 wt females
58 wt females
48 wt males
33 wt males
36 ant females
33 ant females
35 ant males
15 ant males
101 wt females
96 wt females
106 wt males
91 wt males
58 ant females
62 ant females
52 ant males
54 ant males
In the first aspect of crossing focusing on the E1 data, there were 46 wild-type females and 58 wild-type females in the second crossing. This was aided with the aspect of 48 wild-type males in the first crossing and 33 wild-type males in the second crossing. The first crossing focuses on the crossing between antennapedia female and wild type males. The second crossing focuses on the crossing of the wild type females and antennapedia males. According to the results of the first bottle in the context of the F1 data, (first crossing), the outcome illustrates 46 wild type females and 48 wild type males. The data also illustrates the concept of 36 antennapedia females in comparison to 35 antennapedia males. In the second crossing within the context of the F1 data, the outcome illustrates 58 wild type females in comparison to 33 wild type males. The data also indicates the outcome of 33 antennapedia females and 15 antennapedia males. In the second bottle (F2 crossing), the outcome illustrates 101 wild type females and 106 wild type males. The data also illustrates the concept of 58 antennapedia females in comparison to52 antennapedia males. In the second crossing within the context of the F2 data, the outcome illustrates 96 wild type females in comparison to 91 wild type males. The data also indicates the outcome of 62 antennapedia females and 54 antennapedia males.
According to the results of the first crossing, mutations of the wild type females are dominant over the genes of the wild type males. This is essential in the outcome of the large number of antennapedia wild type females and males. The dominant mutation in this context of crossing is illustrated through A+. In the second crossing in relation to the F1 crossing, the dominant gene is the X chromosomes of the antennapedia wild type males. This is essential in the illustration of the outcome of the crossing with the essence of various antennapedia flies with reference to the results as indicated in the F2 table or data. The two sets of data are applicable in the examination of the frequency of different types of double exchanges.
The results from this experiment confirm the essence of relative frequencies of two and four strand double exchanges. There is no existing assumption in relation to the 1:1 ratio for the crossing with reference to F1 and F2…