Drosophila melanogaster, commonly known as fruit flies, is commonly used as a model organism in chromosomal genetic studies of inheritance. The reason they are considered an attractive organism is because their genome has been widely studied and mutations have been found to be present in every locus. Also, their generation time is only two weeks, obtaining a large sample size is easy, and their cultures are cheap to maintain (Plunkett and Yampolsky, 2010). Additionally, a complete lifecycle of Drosophila only takes 10 days through four distinct stages (Arbeitman, Furlong, Imam, Johnson, Null, Baker and White, 2002). This species begin their life as an egg, which a naked human eye cannot see. The larva soon hatches from the egg, molts twice …show more content…
In the pupa stage the eyes, wings, and legs become visible. After 4 days in the pupa stage, the adult Drosophila will emerge and will appear as a light white color, after a few hours they will darken and the Drosophila’s features will become more visible (Arbeitman, et al., 2002). Once the Drosophila is an adult, it is able to mate with other Drosophila. When mating Drosophila, it is crucial to start the parental cross with virgin females in order to obtain accurate results (Menon, Varma and Sharma, 2014). This is because female Drosophila have the ability to store sperm for a lifetime, therefore if female virgins are not used, it is impossible to know for sure the type of male gamete the female would give to her offspring. With that being said, all adult Drosophila must be cleared out of the culture vial before the pupa hatch. After the first pupa emerges, the Drosophila can only be scored up to 2 weeks to prevent the risk of scoring the wrong generation (Menon, et al., …show more content…
The wild-type and mutant stock vial were anesthetized and 7 wild-type virgin females and 7 mutant males were added to a new culture vial. In a different culture vial, 7 mutant virgin females and 7 wild-type males were added.
Analysis of F1 and F1 Self Cross
The Drosophila was anesthetized and the F1 cross corresponding to the wild-type female x mutant male parental cross was created with 7 winged females and 7 winged males. The F1 cross corresponding to the mutant female x wild-type male parental cross, was also created with 7 winged females and 7 winged males. The F1 generation of each parental cross was scored until 100 flies were counted for each vial. All excess Drosophila was disposed of in the fly morgue.
Analysis of F2
The F2 generation of each F1 cross was anesthetized and scored until 100 flies were counted from each vial. All of the Drosophila was then disposed of in the fly morgue.
Chi-Square
Test 4: All three phenotypic frequencies saw a reduction in their number as the homozygote fishes saw a reduction in their number and were not able to pass on their alleles to create either their colored fish or a heterozygote. Both yellow and blue allele frequencies decreased by the same
The gels were run at 90-100 volts for 1-1.5 hours. Upon completion of the experiment, we were able to examine the DNA. First, the electrophorese. revealed that three of the fourteen samples were homozygous while the other eleven were
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
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.
Nettie studied Tenebrio molitor beetles and found that unfertilized eggs in female beetles always contain an X chromosome. Sperm from male beetles contain either an X chromosome or a Y chromosome. She found that eggs fertilized by sperm carrying the X chromosome produce female beetles. The combination of egg and Y-chromosome sperm produce male beetles.
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.
Sexual reproduction is that the union of male and feminine gametes to create a fertilised egg or zygote. The ensuing offspring inherit one-half their traits from every parent. Consequently, they 're not genetically similar to either parent or siblings, except within the case of identical twins. As theorised by Mendel, adults are diploid, meaning as 2N, having 2 alleles offered to code for one attribute. The gametes should be haploid, signified by N, containing just one allele in order that once 2 haploid gametes mix, they manufacture a traditional diploid individual. The method where haploid sex cells are created from diploid parents is known as meiosis, and it happens solely within the reproductive organs.
The exercise involved a series of ‘mating’ events resulting in 6 generations. Each mating event produced offspring with ‘possible’ newly inherited traits. The idea of ‘chance’ was included through simple coin tosses. Also, ideas of selection and mutations were introduced into the ‘gene pool’, which presented a deeper and more clear understanding of Mendelian inheritance and the Hardy-Weinberg equilibrium. Upon reaching the third generation, A B1 mutant allele was introduced to the blue locus-influencing fin shape and a G1 mutant allele was introduced to the green locus-influencing Mouth
Daly and Wilson also refer to the research done by a British geneticist named A.J. Bateman to strengthen their arguments for the idea of status competition. Bateman's research focused on lab experiments done on Drosophila or fruit flies. The experiments consisted of taking fruit flies with "distinct genetic markers" and placing them in jars. It was made sure that each jar contained an equal number o...
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%.
In my third year at Michigan State, I was enrolled in a class called Research in Biology. The goal of this course was to determine if there was a genetic marker to tell three different species of Rhagoletis flies apart due to their shared phenotypes and the infestation of apples, which became quarantined when one species was found in the orchards. If the other two species were found in the orchards, they would do no harm and the apples would be safe. Using their mitochondrial genomes, we ran gel electrophoresis and Nanodrop analysis and sent the DNA to Michigan State’s genomic core lab to be processed by Illumina. After getting the data back, our lab used a development node called Trimmomatic to eliminate adapter sequences, poor quality control bases, and ambiguous bases.
The idea of the project was to experiment breeding Drosophila Melanogaster (fruit fly) to figure out if certain genes of that species were sex linked or not (autosomal). A mono-hybrid cross and di-hybrid cross was performed. For the mono-hybrid cross, white eyed female and red eyed male were placed in one vial for them to reproduce. For the di-hybrid cross, red eyed and normal winged flies and sepia eyed and vestigial winged flies were placed in their vial to reproduce. In the mono-hybrid cross the results expected were within a 1:1:1:1 ratio. Expected results similar to the expected desired null hypothesis proposed with what the F1 parental generation breeds. The potential results would have had to have been within the ratios of 9:3:3:1. The results were clear and allowed the null hypothesis to be correct. The white eyed gene in the fruit flies is sex linked. Sepia eyes and vestigial wings are not sex linked and are examples of independent assortment.
Insect, small, air-breathing animal characterized by a segmented body with three main parts—head, thorax, and abdomen. In their adult forms, insects typically have three pairs of legs, one pair of antennae, and in most instances, two pairs of wings. Insects rank among the most successful animals on Earth. About one million species of insects have been identified so far, which is about half of all the animals known to science. That is why for every pound of human on the earth there are 10 pounds of insects. So that is why there are many reasons why insects are so successful, their exoskeleton, their size, their body function, the way they reproduce, and their development of metamorphosis.