Sordaria Fimicola Lab Report
Nicole Hain
Bio 110
Sordaria fimicola Lab Report
Introduction
“Evolution Canyon” consists of two slopes in Israel that are close in proximity, but have a huge difference in environment. This makes the slopes a good model system for exploring evolution, especially because they’re so close to one another. The South Facing Side (SFS) receives more sunlight than the North Facing Side (NFS). This extreme sun exposure causes the South slope to have drought and arid conditions whereas the North side has more temperate conditions and is shady and humid. The model, Sordaria fimicola, reproduces through the process of Meiosis and their chromosomes cross over in Prophase I (Stern). S. fimicola have different crossover frequencies between the slopes in Evolution Canyon; there are higher crossover frequencies on the SFS compared to the NFS. One possible explanation of this outcome is the harsh conditions on the South side causing an increase in crossing over. To prove if climate conditions really did have an effect on crossover, we controlled the conditions in lab on common lab strains of dark and tan Sordaria. Having lab strains of Sordaria fimicola makes it a good model organism because it has a short life cycle, produces fruiting bodies, and it’s easy to keep alive. The defining characteristic of the phylum Ascomycota is the production of four to eight sexual spores in a sac-like cell called an ascus (Lamb). As stated before, S. fimicola reproduces through Meiosis where crossover occurs in Prophase I. The process of meiosis can cause three patterns to arise in asci; a 4:4 pattern has four black spores and four tan spores next to each other. This occurs when there is no cross over between the different strains. A 2:2:2:2 and 2:4:2 pattern result from crossover; the set patterns are determined through Meiosis. As soon as Meiosis II is complete and there are four daughter cells in the ascus, the pattern is determined. Mitosis is the final step in completing the process; at
Bio 110
Sordaria fimicola Lab Report
Introduction
“Evolution Canyon” consists of two slopes in Israel that are close in proximity, but have a huge difference in environment. This makes the slopes a good model system for exploring evolution, especially because they’re so close to one another. The South Facing Side (SFS) receives more sunlight than the North Facing Side (NFS). This extreme sun exposure causes the South slope to have drought and arid conditions whereas the North side has more temperate conditions and is shady and humid. The model, Sordaria fimicola, reproduces through the process of Meiosis and their chromosomes cross over in Prophase I (Stern). S. fimicola have different crossover frequencies between the slopes in Evolution Canyon; there are higher crossover frequencies on the SFS compared to the NFS. One possible explanation of this outcome is the harsh conditions on the South side causing an increase in crossing over. To prove if climate conditions really did have an effect on crossover, we controlled the conditions in lab on common lab strains of dark and tan Sordaria. Having lab strains of Sordaria fimicola makes it a good model organism because it has a short life cycle, produces fruiting bodies, and it’s easy to keep alive. The defining characteristic of the phylum Ascomycota is the production of four to eight sexual spores in a sac-like cell called an ascus (Lamb). As stated before, S. fimicola reproduces through Meiosis where crossover occurs in Prophase I. The process of meiosis can cause three patterns to arise in asci; a 4:4 pattern has four black spores and four tan spores next to each other. This occurs when there is no cross over between the different strains. A 2:2:2:2 and 2:4:2 pattern result from crossover; the set patterns are determined through Meiosis. As soon as Meiosis II is complete and there are four daughter cells in the ascus, the pattern is determined. Mitosis is the final step in completing the process; at