Sordaria Lab Report
Meiosis and Genetic Diversity in Sordaria
979554296
Biology 110 Lab
Introduction: In Israel there exists multiple spots in the mountains called Evolution Canyons, which are all located between a southern facing slope (SFS) and a northern facing slope (NFS). What’s particularly interesting about these locations is that despite the two slopes being on opposite sides of a small canyon, they exhibit extremely contrasting conditions. The SFS receives multiple times the UV radiation from the sun that the NFS receives, has fluctuating weather, and is generally an arid and less hospitable region compared to the temperate, stable environment of the NFS. Scientists collected wild type Sordaria fimicola inhabiting both slopes and discovered that the strains from the SFS exhibited higher mutation rates (more crossover of genes) than those from the NFS. This observation could be attributed to the conditions of the SFS, which are far harsher and more unpredictable than those of the NFS; organisms living in those kind of conditions reasonably should exhibit greater mutation and crossover of genes in order to boost genetic diversity which should allow for organisms to better adapt to changing conditions and still maintain their fitness. This experiment is meant to study this phenomenon under controlled lab conditions to observe how the crossover frequencies of S. fimicola may change under the “environmental stresses” of standard lab conditions. The general hypothesis for this experiment is that if increased crossover and mutation of DNA occurs in organisms when they are subjected to more extreme and variable conditions, then the S. fimicola strains grown in “optimal” and constant laboratory conditions should exhibit less crossover of genes. Without any pressing environmental stresses on the fungi, the tendency for genes to switch positions and need for increased genetic diversity should in fact be diminished. Two different strains of S. fimicola (tan mutant strain, gray
979554296
Biology 110 Lab
Introduction: In Israel there exists multiple spots in the mountains called Evolution Canyons, which are all located between a southern facing slope (SFS) and a northern facing slope (NFS). What’s particularly interesting about these locations is that despite the two slopes being on opposite sides of a small canyon, they exhibit extremely contrasting conditions. The SFS receives multiple times the UV radiation from the sun that the NFS receives, has fluctuating weather, and is generally an arid and less hospitable region compared to the temperate, stable environment of the NFS. Scientists collected wild type Sordaria fimicola inhabiting both slopes and discovered that the strains from the SFS exhibited higher mutation rates (more crossover of genes) than those from the NFS. This observation could be attributed to the conditions of the SFS, which are far harsher and more unpredictable than those of the NFS; organisms living in those kind of conditions reasonably should exhibit greater mutation and crossover of genes in order to boost genetic diversity which should allow for organisms to better adapt to changing conditions and still maintain their fitness. This experiment is meant to study this phenomenon under controlled lab conditions to observe how the crossover frequencies of S. fimicola may change under the “environmental stresses” of standard lab conditions. The general hypothesis for this experiment is that if increased crossover and mutation of DNA occurs in organisms when they are subjected to more extreme and variable conditions, then the S. fimicola strains grown in “optimal” and constant laboratory conditions should exhibit less crossover of genes. Without any pressing environmental stresses on the fungi, the tendency for genes to switch positions and need for increased genetic diversity should in fact be diminished. Two different strains of S. fimicola (tan mutant strain, gray
References: Cyr, R. 2002. Overview, Life and Natural Selection. In, Biology 110: Basic concepts and biodiverity course website. Department of Biology, The Pennsylvania State University. http://www.bio.psu.edu/ Meiosis and Genetic Diversity in the Model Organism, Sordaria. Written by Hass, C. and Ward, A. 2010. Department of Biology, The Pennsylvania State University, University Park, PA. Sordaria crossing over picture: https://sites.google.com/a/canacad.ac.jp/sl1-biology-ferguson/labs/unit-7-meiosis