The Affect of Environmental Conditions on Gene to Map Distance in Sordaria Fimicola

Abstract:

This paper analyzes whether or not gene to map distance in Sordaria fimicola is affected by changes in environmental conditions. The main focus is on how temperature affects the recombination frequency in this organism. It is analyzed if under different environmental conditions wt x gray and wt x tan varies in their percent crossing over. It is investigated how factors such as temperature and ultraviolet light have affected the gene to centromere distance in Sordaria. Results obtained in lab as well as scientific researches prove that as temperatures increases the percent of crossing over increases as well.

Introduction:

Sordaria fimicola belongs to the kingdom of fungi and is part of the phylum Ascosmycota. This fungus habitat is in the feces of herbivores. As many fungi Sordaria have one life cycles which is haploid/ diploid. It is commonly exits as a haploid organism, but when the mycelium from two individuals meets, the result is a diploid zygote. This diploid zygote which undergoes meiosis forms eight haploid ascospores . The ability of Sordaria to make 8 haploid ascospores is what makes it unique and important for the laboratory exercise done in lab.

The laboratory performed had as a purpose to determine the change in crossing-over frequency or the also called map distance under different environmental conditions in Sordaria sp. This paper has a purpose to analyze with the help of scientific research the results obtained in the laboratory exercise. To investigate the crossing over in Sordaria sp., a cross between two mutant strains was performed. The mutant strains used had different genes for spore color. Tan and gray spore-color mutants are used.

The wild type of the spore color of the ...

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...the total number of asci X 100. In order to calculate the map distance, it was necessary to divide the percentage of crossover asci by 2. This has to be performed because only half of the spores in each ascus are result of crossing over. Each student had to count, at least 100 spores, in order to determine if crossing over occurred in a particular perithecium. A data was collected to determine whether various environmental conditions affected the crossing over in Sordaria sp.

In the case of temperatures the cultures were incubated at each determined temperature. For the UV radiation, cells were exposed to UV light for 10 seconds and then grown in 30oC. For the EtBr treatment, 50ul of EtBr was added to the growth medium and cells were incubated at 30oC. In the case of sunlight exposure, cells were exposed to sunlight directly and grown at room temperature