Pre lab activity before you begin the online lab, sordaria in the figure below, a cross between two haploid strains of sordaria produces spores of different colors where the growing filaments of the two strains meet, fertilization occurs and zygotes form. Alexander charles, what a nice name i wonder if mrcharles was an english teacher in his poem star-crossed, charles talks about two skeletons discovered in mantua italy. Colonies of sordaria fimicola the plates were inoculated by placing small pieces of agar containing mycelia from both wild and tan-spored parental strains at four positions on the plate.
Two weeks before the fungi lab, crosses between the wild type and the tan strains of sordaria are prepared each lab member needs a petri plate with a sterile crossing agar a wax is pencil is utilized to draw a line on the bottom of the plate deciding it into quarters. 1 demonstration of crossing-over during meiosis in sordaria fimicola introduction sexual reproduction is a special case of cell reproduction in which the genes of two. In both neurospora and sordaria, the ascospores are partitioned at the eight-nucleus stage, and ascospores in eight-spored asci are initially uninucleate evidently, in hybrid crosses of the family sordariaceae, ascospore partitioning can be delayed until after one or.
Determine if they are linked the laboratory extends over 3 weeks students set up the cross during the first week asci mature during the second week and are held in the refrigerator until the third stock plates of gray spore and tan spore sordaria strains (1 each per four students, used to set up in sordaria fimicola (figure 11),. Please place a screenshot of the video into a new page of the google doc and add as many screenshots of the animation as necessary to completely and thoroughly describe the video using captions that you will synthesize from your text book. At the grey (g) spore colour locus in sordaria fimicola from crosses, with outside markers present, between g locus mutants and wild type, or involving pairs of g locus mutants that differed in spore colour (g locus mutants range from grey to hyaline) this colour difference enabled asci. The objective of this lab was to study and test the sordaria fimicola fungus crossover by determining what color it will yield during meiosis a cross over that will be between the wild type and the mutant alleles my hypothesis for this experiment is that all the mutant allele will appear in the. Sordaria crosses leave a reply in another lab project i am considering for the fall class, i have been experimenting with crossing sordaria fimicola fungi these are molds in the huge phylum of ascomycete fungi that have spores in filaments , which are ordered meiotic products so it is an excellent example of meiosis and genetic.
In a cross between a wild-type strain of sordaria fimicola, c7, having black ascospores and a mutant of the same strain, c7h (olive, 1956) with hyaline spores, it was noticed that spore colour was not segregating in a unifactorial pattern (plate 37, no i. You perform a cross between a sordaria (fungal) strain of genotype a, e and one of genotype a, e genes a and e are linked the centromere is between them. Cross-over events in harsh environments if they do not have comparable data from sordaria that was grown in ideal conditions 1 a perithecium contains many asci that can be seen under a microscope once the. Plant pathology 526 advanced fungal biology spring 2014 laboratory #1 – genetic crosses of sordaria fimicola setting up the matings: 1 find the stock plates of the wild type, gray spore mutant and tan spore mutant strains. Figure 6: sordaria cross plate 1 in each group of 4 students, 2 will set up and work on the wild/tan cross and 2 will set up and work on the wild/gray cross 2 use a scalpel to gently scrape the surface of the nutrient medium where the two strains lab 10 - meiosis and tetrad analysis.
The percentage of second ds for mutations isolated from sfs strains was generally higher (average, 600% in crosses to sfs wild types, 560% in crosses to nfs wild types) than those from nfs strains (555% in crosses to sfs wild types, 542% in crosses to nfs wild types), although their sites are intermingled along the chromosome. The sordaria cross notes 1 sordaria- fungi, easy to grow and look at mutant strain 2 cross, grow together, spores will fuse 3 diploid nuclei, undergoes dna replication, meiosis 1, meiosis 2 4 4 haploid cells ½ of genetic info from diploid parent cell 5 fungi: haploid in general, 1 haploid fuses with another haploid to create next generation 6 different lifestyle 1 cell formed from. Mapping genes in sordaria (tan) ascospore sordaria on the bottom of the cross plate write your initials with the cross plate upside down, center the petri plate over figure 3 below mark the + and t on the bottom of the cross plate now turn the plate right side up. A cross of sordaria fimicola wild type and the mutant tan strain for demonstrating genetic crossing-over for use with advanced placement® biology laboratory #3 or as a separate refresher demonstration from the exercises found in our sordaria genetics kits (item# 155847 and item# 155848. This video looks at meiosis in sordaria it considers how frequencies of cross over can lead to mapping the location of the gene producing spore color.
The crosses were set up by dividing an agar plate into fourths, and placing two pieces of black sordaria strains alternating with two pieces of gray or tan sordaria strains they then were placed in an incubator at room temperature for two weeks to allow sufficient time for it to reproduce. Sordaria crossing over : sordaria crossing over this activity involves observing the results of crossing over in a fungus, sordaria a cross between two haploid strains of sordaria produces spores of different colors. The utility of sordaria in genetics stems from its very strict method of sexual reproduction it is a member of the ascomycota, which means that it bears its sexual (meiotic) ascospores in a sac called an ascus in turn, the asci are borne in a special fruiting structure called a perithecium.
Abstract supplementation with dna bases in crosses of sordaria fimicola heterozygous for spore color markers (g 1, h 2) within the gray-spore (g) locus has been found to cause significant alterations in patterns of gene conversion at the two mutant siteseach base had its own characteristic effect in altering the conversion pattern, and responses of the two mutant sites to the four bases were. The genotypes are given of over 4500 asci showing aberrant segregation at the grey (g) spore colour locus in sordaria fimicola from crosses, with outside markers present, between g locus mutants and wild type, or involving pairs of g locus mutants that differed in spore colour. Summary asci showing aberrant segregation at the buff spore colour locus in sordaria brevicollis were selected from crosses between buff mutants and wild type in the presence of closely-linked flanking markers the frequency of crossing-over associated with aberrant segregations was calculated and corrected to allow for crossovers between the flanking markers incidental to the aberrant. Sordaria fimicola is an ascomycete fungus sordaria is a haploid (n) organism for most of its life cycle when the mycelium from two individuals meet, a diploid zygote (2n) is formed.
In the figure below, a cross between two haploid strains of sordaria produces spores of different colors where the growing filaments of the two strains meet, fertilization occurs and zygotes form meiosis occurs within fruiting bodies to form haploid ascospores, spores contained in asci (special sacs. To enable screen reader support, press ctrl+alt+z to learn about keyboard shortcuts, press ctrl+slash.