Biology 260: gENETICS
CROSSES OF SORDARIA
Sordaria of Tan and Grey Allele
To understand the details of genetic behavior, Sordaria fimicola is used in this study by observing the asci produced from monohybrid and dihybrid crosses with observance to recombination. This experiment performed extended over a three week period. The strains that were used from S. fimicola were wild type producing black, and mutants producing grey and tan strains. There are seven possible phenotypes as a result from second division segregations through the dihybrid crosses. Map units were found through results of the monohybrid cross. Expected map unit results are 33 mu for grey and 28 mu for tan. However, our results differ from that expected, 24.7 mu for the grey and 25.1 for tan. The differentiation may be due to certain factors like temperature, time, and maturation of the perithecial. Introduction:
S. fimicola is a fungus that produces asci contained in a perithecium, and individual ascus’ have ordered ascospores that are used in studies of genetics because through ascospores is the way S. fimicola reproduces. S. fimicola has a short life span and is good in studies for genetics because S. fimicola stays in a haploid state and also tetrad analysis allows for a direct observation of crossing-over. This study is extremely helpful in understanding crossing over because it’s easy to see that the genetic material that were previously on separate homologs have combined, and through laboratory experiment there’s a visual interpretation of genetic variation (Glase, 2005). S. fimicola is an excellent candidate for studying recombination and genetics and has been used in many studies. Studies of this fungus, for educational purposes and the establishing was first accomplished by obtaining spore colored mutants of S. fimicola through ultraviolet irradiation in 1956. Further, the mutants of S. fimicola were crossed with the wild strain resulting in visible...
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