White Eyed Phenotypes

The observed results from the ¬F1 generation were that the phenotypes had to be EeNn x EeNn. The expected results for the F1 generation were also EeNn x EeNn because the P generation phenotypes for the male fruit fly were Ee and were Nn for the female P generation flies. The expected results for the F2 generation were a 9:3:3:1 ratio from the phenotypes NENenEne x NENenEne. The Chi squared value turned out to be 4.14 when the differences between observed and expected results were

DROSOPHILA CULTURE We will study basic principles of Mendelian inheritance with the use of the fruit fly, Drosophila melanogaster [the name means “black-bodied fruit-lover”]. Drosophila was one of the first organisms to be studied genetically: its small size, short life cycle (10 ~14 days at 25oC), high reproductive rate (an adult female can lay 400-500 eggs in 10 days), and ease of culture and genetic manipulation have made it perhaps the best understood animal genetic system. Many different species, and a large number and wide variety of naturally-occurring and artificially-induced genetic variants are available. The partial genetic map in Appendix B describes the location of all the mutations used in

When examining the D. Melanogaster mutants in the lab, our group immediately noticed an apparent difference from the wild-type flies. None of the mutants were able to fly. This led us to believe that we were dealing with a wing mutation. Upon further examination, we concluded that it was the overall wing shape that prevented the mutants from flying. The wing shapes among the mutants varied in both size and shape. Some were long, while others were short. The mutant wings could be distinguished into two general classes. One division of the mutant wing was short and stubby, almost a fourth the size of the wild-type wing. The rest of the mutants ranged in wing size and length, however many mutant wings were the same length as the wild-type wings. Although the

Genetics shows us that we inherit traits in many different ways. A perfect example to show us the different ways we inherit traits is fruit flies. Fruit flies are commonly used by scientists to conduct genetic experiments due to their reaction to the experiment being very quick. Scientists mainly look at how the flies inherit basic traits such as brown body color, or red eyes(basic trait flies are known as wild-type flies) from their parents, but sometimes they can come across some abnormal traits. Some of these abnormal traits include having a yellow body color or having curly shaped wings and have made scientists wonder how the flies have inherited these specific traits. So how do the flies inherit

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.

We began with F1 generation set of flies consisting of dihybrid males and females. The F1 generation consisted of all heterozygous genotypes. By examining the F2 offspring’s at the end of the lab and using the Chi-square test to test our hypothesis we were able to determine

In 1910, a single white-eyed mutant was found in a Drosophila melanogaster population, which usually has dark red eyes. The mutant was male. It was crossed with wild-type females and over generations led scientists to conclude that this mutation was somehow physically connected to the “factor” that determined sex. Crossing white-eyed males and red-eyed females from the second generation produced equal number of offspring with each eye color. Males have white eyes when they inherit the gene on the X chromosome from their mother. Females only show the trait if they inherit mutant genes on both X chromosomes. This can be demonstrated by using a Punnett Square to show allele frequencies with dominant and recessive

Based upon observation of the F1 generation, we hypothesize that the inheritance of the white-eye (W) mutation is sex-linked and recessive wild type.

Using b for blue eyes and B to represent the brown eyes the genotype of the man would be BB or Bb this is because to have the brown eyes the gene for that must be dominant in order to be able to be transferred to the kids.

Drosophila melanogaster is a species of fruit fly, used as a model organism in genetics research. We used this species to test the pattern of inheritance of two traits; eye color and wing type. With Mendelian Genetics, we assume genes are not linked. Thus, our hypothesis is that the genes are not linked. We ran two crosses, one with a wild type female and mutant male, and one with a mutant female and wild type male. We then proceeded to look at the two generations following this original cross; the F1 generation, or children of original cross, and the F2 generation, created when the flies from F1 were crossed again (essentially breeding the children amongst each other), using wild type females with wild type males, and wild type females and mutant males. Looking at our results in a chi square test, we find that we reject the assumption that the genes are not linked for cross 1, and accept that they are not linked for cross 2. However, we know that the trait for eye color is X-linked, and the trait for wing type is autosomal, so they cannot be linked. Thus, something must have gone wrong in our lab procedure.

After female fly laid eggs, it took 1 day for embryos to developed and hatched into a worm-like white larvae, attempting to eat as much of the food for storage and prepared for pupation. From day 3-4 (first, second, and third instar larva), white larvae stopped eating and formed an immobile brown pupa. On the next 4-5 days, the body began to give the adult wings form and hatched in the next 3-4 hours. The newly enclosed flies look very pale, larger in size and poor pigmentation compared to adults. The whole timing was 25 C, set for both wild type and mutant. Mutant’s eyes are more sparkles than their wild types so their nickname is “diamond”. One of the possible genes would rise to the mutant phenotype is ruby, rb, 1-7.5 which decreased the number of pigmentation of eye cells [4]. Mutations in carnation, car, 1-62.5 and henna, hn, 3-23.0 characterized eye mutation and cell defected which caused eyes texture deficiency [1, 2]. Also garnet, g, 1-44.4, contributed to slight roughness eye mutation [5] and moire, me, 3-19.2 affected the expression of normal eye texture gene of wild type population [3]. Observation of the mutant flies possibly shown that the phenotypic “diamond” is 100%. Thus the penetrance is 100% in the all the mutants. Environment and genetic background displays a key role in expressivity of mutant

This experiment looks at the relationship between genes, generations of a population and if genes are carried from one generation to another. By studying Drosophila melanogaster, starting with a parent group we crossed a variety of flies and observe the characteristics of the F1 generation. We then concluded that sex-linked genes and autosomal genes could indeed be traced through from the parent generation to the F1 generation.

The mode of inheritance for the four traits of eye shape, eye color, bristle morphology, and body color were studied in Drosophila melanogaster, or commonly known as the fruit fly. Each gene was analyzed through true breeding crosses and then reciprocal crosses of the wild type and mutant flies. The gene for body color encodes either a honey yellow or ebony color in the fly. It was determined that the honey, which is the wild type, is the dominant allele and the ebony color is the recessive allele. Eye color, eye shape, and bristle morphology were all determined to be sex linked on the X chromosome as they are more prevalent in the males. If these genes were found on the Y chromosome, there would be no females found with mutations in the eye

The 20th century was a time of change for many fields of science, but in terms of genetics, Drosophila melanogaster rose as one of the most significant organisms to use as a model for scientific findings to come. Drosophila melanogaster is a small fly, approximately 2 mm in length that feeds on old, decomposing fruit. Over its 100+ years as a model organism, two decades, 1910-1920 and 1970-1980, proved to hold Drosophila melanogaster in utmost importance. Thomas Hunt Morgan, who did most of his work at Columbia University, led the first decade. He set forth the standards for transmission genetics and proved his theory that genes were located on individual pieces made up of DNA known as chromosomes. Furthermore, his methods and theories proved useful in the second decade and were used to establish control of the genetics of organisms. Specifically, this involved how the organism’s genes behaved and developed over time (Roberts 2006).

The purpose of this lab was to develop the understanding of the inheritance patterns using fruit flies, Drosophila Melanogaster. We chose Drosophila Melanogaster because of the fact that they are small and are an easy use in the laboratory. As well, they have qualifying characteristics to be able to use. They are very easy to distinguish the differences between female and males, have a short life cycle, inexpensive, and understandable traits to be a perfect example. Also, fruit flies produce a large amount of offspring, which helps us out when finding out pattern of inheritance (Morris and Cahoon, p. 5). In