Drosophila Fruit Fly

The motivation of this lab report is to use Mendel’s Laws of Inheritance to analyze and predict the genotypes and phenotypes of an offspring generation (F2) after knowing the genotypes and phenotypes of the parent generation (F1). The hypothesis for this experiment is that the mode of inheritance for the shaven bristle allele in flies is autosomal recessive in both male and female flies.

It was decided that there would be 80 vestigial flies and 20 wild type flies to total to an initial population of 100 drosophila. Next, the flies were anesthetized flies using Fly Nap. The flies were counted out to reach desired ratio, sexing the flies making sure there are equal amounts of males and females to be sure there is ample individuals to allow successful mating. The fly’s food was prepared by taking a frozen rotten banana, cutting it in half, mashing up the banana meat, and mixing yeast into it. The

We started out with three populations; B, D, and G. In order for us to properly create controlled genetic crosses, we had to ensure that all the female flies were “virgins”.

Again the flies were sorted and the first twenty males and twenty females were chosen and their body phenotypes were recorded. The same transfer techniques were used to place the flies in the fresh culture vial. The excess flies were disposed of in the morgue. The allele frequencies and expected heterozygosities at each transfer were

Steps 7-11 were repeated to record the phenotype of the F2 generation and number of male or female flies.

METHODS: In this experiment, the instructor provided us with 30 ebony individuals and 20 wild type individuals. In order to get an exact amount of each type, we anesthetized the flies and counted them off by gently using a fine point paint brush. Then all 50 Drosophila were put into a population cage which had a lid that had six holes for the centrifuge tubes. Two food tubes and four clean, empty tubes were added on the first day. Each food tube consisted of half a cup full of food mixed with 6-7 milliliters of water. This was the fly medium. The food should turn blue once the water is added. Each tube was labeled with a number and with the date. Every two to three days we added one more food tube until all 6 tubes contained the fly medium. After all 6 tubes were filled, the following days after we exchanged the first food tube with a new food tube. At the end of the experiment, we fed the flies with a total of 8 food tubes. Then the flies were anesthetized, again. At the end of this four week lab, the number of living ebony and wild

It would be expected that the mutant F1 flies would be heterozygous for the allele responsible for the grounded trait. If two F1 flies were mated, the percentage of flies that would be expected to be wildtype in the F2 generation would be 25% mutants given that the mutant allele (ap) is predicted to be recessive and, leaving 75% to be wildtype (ap+).

we said goodbye and placed them in the fly morgue. We allowed the F2 larval

This lab had 2 exercises. Exercise 9.1 involved observing pictures of 60 F2 offspring and recording the phenotypes for 6 different traits. Exercise 9.2 required us to perform the “chi-square test” to determine whether the data we collected matches the standard Mendelian ratio.

11. The progeny of a Drosophila female (heterozygous at three loci: y, ct, and w) crossed to a wild type male are listed below:

The F1 generation that we had just decanted was then moved to a dissecting microscope for scoring, this generation included 20 Drosophila flies that we could then inspect for different traits using the microscope (traits being the sex of

The parents are both homozygous. The homozygous dominant would represent the wild type. And the homozygous recessive would represent the other fly parent of a different strain. The F1 generation would consist of 100% Wild Type but they would all be heterozygous in carrying the recessive gene.

The spotted wing Drosophila suzukii (Diptera: Drosophilidae) is an attacking pest of berries crops. Unlike most other Drosophila, this insect can oviposit into ripe and ripening berries, so that they make them unmarketable. D. suzukii is spreading quickly throughout the continental US and they give a serious damage in horticultural areas and the fruit industry. Spotted wing drosophila (SWD) puts its eggs in both commercial fruit and wild fruits, so it is of great concern to fruit and vegetable growers. It became a pest of economic significance, but it is important point that requires early detection, monitoring and moderation to control it. Last researches show that D. suzukii infests a number of wild plant species and also those may be harvested commercially like cranberry. Gray dogwood (Cornus racemose Lam.), Tatarian honeysuckle (Lonicera tatarica Linneaus), Mulberry (Morus alba L.), Nanking cherry (Prunus tomentosa L.), Common chokecherry (Prunus virginiana L.), Common buckthorn (Rhamnus cathartica R. Davurica), Elderberry (Sambucus Canadensis L.), White snowberry (Symphoricarpos albus L.), Yew (Taxus

This may have been the cause of the low numbers of white lozenge in the F2 generation of flies. However, the cause of white eyes is a defective red pigment gene and should not affect the vision of the flies, whereas the lozenge gene should have a greater affect due to it causing the malformation of the fly's eyes. Therefore the lozenge flies should have also been in lower than expected numbers, but it was found that they were actually in higher than expected numbers making the validity of this argument questionable.

For our first generation (F1) of flies we chose to cross apterous (+) females and white-eye (w) males. We predicted that the mutation would be sex linked recessive. So if the female was the sex with the mutation then all females would be wild type heterozygous. Heterozygous is a term used when the two genes for a trait are opposite. The males would all be white eye since they only have one X chromosome. If the males were the sex that had the mutation then all the flies would be wild type but the females would be heterozygous.