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Drosophila Melanogaster Lab Report

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Identifying unknown phenotypes and determining mechanisms of inheritance of various genes in mutations of Drosophila melanogaster
Michael Fisher, Tori Hall, Lindsey Theodore

Crosses carried out with Drosophila melanogaster can be used to determine mechanisms that modify ratios of Mendelian inheritance, such as autosomal dominant and recessive inheritance, genetic linkage, and epistasis. To identify the eye color phenotypes of two unknowns (U3 and U4), crosses were carried out between the unknowns and flies with known eye color mutations (sepia, white, cinnabar, scarlet, brown, and vermillion) and the F1 generations were observed. Thin layer chromatography was also used to identify the unknowns by showing the pigment composition of each eye …show more content…

melanogaster is excellent in studying and observing genetic traits, this is due to the flies’ rapid reproduction, numerous offspring, and three chromosome genome.2 Of these three chromosomes, the X chromosome is essential in determining sex, as sex is determined by the ratio of X chromosomes to autosomes in D. melanogaster.2 Male and female D. melanogaster can be distinguished by certain morphology differences. Females are usually larger than males, with stripes along their entire abdomen.3 Males, instead of having stripes at the end of the abdomen, usually have a dark spot at its tip.3 …show more content…

The crosses were set up, and only cinnabar provided offspring that were not wild type leading to the belief that the genotype shown was true cinnabar. Thin layer chromatography

Cross Female Count Male Count Eye Color st ♀ x U3 ♂ 36 25 Brick red st ♂ x U3 ♀ 17 20 Brick red v ♀ x U3 ♂ 3 4 Brick red v ♂ x U3 ♀ 11 7 Brick red cn ♀ x U3 ♂ 16 16 Bright red cn ♂ x U3 ♀ 48 23 Bright red bw ♀ x U4 ♂ 28 19 Brick red bw ♂ x U4 ♀ 36 33 Brick red se ♀ x U4 ♂ 0 2 Brown/Black se ♂ x U4 ♀ 15 26 Brown/Black

also showed similarity’s in the extracts of U3 and cinnabar both being a coral color and also on the plates since similar Rf values were recorded. Between observations of the unknown phenotypes, the crosses run that showed the phenotypes and strong similarities in TLC extracts and Rf values there was a strong case showing U3 as cinnabar and U4 as sepia.

Identifying unknown genotypes using thin layer chromatography
Thin layer chromatography was used as a better gauge of what the unknown phenotypes for U3 and U4 were since extracts and Rf values were observes and recorded for all strains and were shown as distinct in values rather than just being observed as one similar trait of wild type as the crosses had

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