Crosses of sordara
For a class of 30 students cross the wild-type sordaria strain with the mutant tan strain hybrid asci are produced containing 4 dark- and 4 light-colored ascospores students then use tetrad analysis to calculate the gene to centromere distance in map units for the mutant tan gene. 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. To enable screen reader support, press ctrl+alt+z to learn about keyboard shortcuts, press ctrl+slash. Shows a wild-type and a mutant cross the arrangement of ascospores in the asci are clearly displayed and are used to estimate the percentage of crossing over between the centromere and the gene that controls the tan spore color. In this video paul andersen shows you how a cross between mutant and wild types of sordaria fimicola can be used to show and measure frequency of crossing-over he begins by reviewing the process.
Creation of sordaria crosses cross plate i illustrates cross between wild-type black and mutant tan strains cross plate ii shows cross between wild-type black and mutant gray strains using a sterilized wooden splint, cut small 05 cm cubes from the stock culture dishes it is important to sterilize all equipment to minimize contamination. 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. Crosses involving spore color mutants of sordaria brevicollis all showed a decline in the frequency of second division asymmetric asci (2:2:2:2's) as the cross matured this decline was due to the preferential maturation and/or discharge of these asci.
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. 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. - let's now jump into understanding meiosis in some depth so let's start with the germ cell as we mentioned already, a germ cell is a cell that it can either go to mitosis to produce other germ cells or it can undergo meiosis in order to produce gametes.
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. 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. Students prepare cross plates and cross wild-type and mutant strains of sordaria fimicola in this advanced genetics laboratory daily observation of the growing culture provides an opportunity to observe the life cycle of a member of the fungal kingdom during meiosis, crossing over occurs in some.
To the left is a photo of asci that resulted from the cross between two tan strains all of the spores are tan below is a photo of asci that resulted from a cross between black and tan strains. 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. 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.
Crosses of sordara
Both neurospora and sordaria belong to the family sordariaceae and in hybrid crosses of both the genera bdmi (and/or msud) appears to uncouple ascospore partitioning from the postmeiotic mitosis, and allows one or more additional mitoses to occur. 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. By means of cross-species microarray analysis using neurospora crassa oligonucleotide microarrays hybridized with s macrospora targets and quantitative real-time pcr, we identified genes expressed under the control of smta - 1 and smta - 2. Alex wilcox october 22, 2014 sordaria lab write up summary introduction background information about phenomenon of increased cross-over frequency found in sfs compared to nfs: sfs receives more radiation than the nfs.
- 11138 032712 publication no 11138 add up and cross over sordaria genetics simulation introduction crossing over occurs during metaphase i of meiosis during crossing over, homologous pairs of chromosomes exchange sec.
- 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.
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. Aberrant asci containing one or more wild-type spores were selected from crosses between pairs of alleles of the buff locus in the presence of closely linked flanking markers. 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.