Sordaria mapping using spore colors Courtney Smith Lab Partner: Ginni Leeman Lab Instructor: Emily Ashe Lab Section: Bio 240 Date: 10-6-17 Abstract Sordaria is an interesting fungus in the facts that it sexually reproduces and goes through a cycle called meiosis. Meiosis goes through quite a few phases starting with Prophase I and going all the way to Telophase II and consists of a process called crossing over or recombination. The purpose of this experiment was to determine the distance of a locus from the centromere and to see how crossing over can occur. This experiment consisted of using a microscope to see the spores and their colors and two dishes of each hybrid cross. These hybrid crosses would be a …show more content…
These fungi are commonly “found in fecal matter (Lichtenstein, Drew)” and will reproduce “sexually to produce spores called, ascospores (Lab 3)”. These “ascospores" are borne in sac shaped structures called ascus. “In turn the asci are borne in a special fruiting structure called a perithecium (Volk, Tom)”, which contains a small opening at the top called the ostiole. Since Sordaria only reproduces sexually and cannot reproduce asexually, it has to be “homothallic” which means it has the ability to reproduce sexually with itself. Now Sordaria “is haploid and spends most of its life cycle in the vegetative state ( Thompson, Laura)” but when the mycelium of two individuals meet then a diploid zygote is formed. This diploid zygote will then undergo meiosis which consist of the phases: Prophase I, Metaphase I, Anaphase I, Telophase I, Prophase II, Metaphase II, Anaphase II, and Telophase II. All of this was done so that it could end up with 8 haploid “ascopores which are contained in a narrow pod-like ascus (Lab 3)”. These asci will eventually burst and release ascopores to start a new colony. Sordaria is both a unique and useful fungus due to certain aspects of meiosis that den be directly investigated due to the formation of the 8 haploid ascopores in the ascus. To be specific the process of crossing over, or homologous recombination, can be seen from …show more content…
Also these results show that the hypothesis was a correct assumption in thinking that MII would produce a higher amount of numbers than MI could. This means that during the experiment that there were twice as many MII in the crosses that MI. All of these results were used to determine the recombination frequency by the equation stated above in methods where the observed frequency was figured then divided by two. The table below shows the recombinant frequency of MII for both