PowerPoint PresentationSlide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29When genes reside on the same chromosome, they are said to be linked (not to be confused with sex linkage); therefore, as the chromosomes go, so go the genes As an example, genes controlling body color and wing form in fruit flies are linked, and normal gray body color (b+) is dominant to black body color (b), and normal wing shape (vg+) is dominant to vestigial wings (vg)Slide 31Slide 32Slide 33Slide 34In the cross b+ b vg+ vg x b b vg vg where the heterozygous/heterozygous individual has the dominant alleles on one chromosome and the recessive alleles on the other and there is no crossing over, only two phenotypes will be produced - Dom/Dom and Rec/RecSlide 36Slide 37Slide 38Slide 39Slide 40Slide 41Slide 42Slide 43Slide 44Slide 45Slide 46Slide 47In the cross b+ b vg+ vg x b b vg vg where the heterozygous/heterozygous individual has a dominant allele and a recessive allele on one chromosome and a recessive allele and a dominant allele on the other and there is no crossing over, only two phenotypes will be produced - Dom/Rec and Rec/DomSlide 49Slide 50Slide 51Slide 52Slide 53Slide 54Slide 55Slide 56Slide 57Slide 58Slide 59Slide 60Slide 61Slide 62Slide 63In the cross b+ b vg+ vg x b b vg vg where the heterozygous/heterozygous individual has the dominant alleles on one chromosome and the recessive alleles on the other and there is crossing over with a 17% recombination frequency, all four phenotypes will be produced, but 83% will be parental-type (Dom/Dom and Rec/Rec) and 17% will be recombinants (Dom/Rec and Rec/Dom)Slide 65Slide 66Slide 67Slide 68Slide 69Slide 70Slide 71Slide 72Slide 73Slide 74Slide 75Slide 76Slide 77Slide 78Slide 79Slide 80Slide 81Slide 82Slide 83Slide 84Slide 85Slide 86Slide 87In the cross b+ b vg+ vg x b b vg vg where the heterozygous/heterozygous individual has a dominant allele and a recessive allele on one chromosome and a recessive allele and a dominant allele on the other and there is crossing over with a 17% recombination frequency, all four phenotypes will be produced, but 83% will be parental-type (Dom/Rec and Rec/Dom) and 17% will be recombinants (Dom/Dom and Rec/Rec)Slide 89Slide 90Slide 91Slide 92Slide 93Slide 94Slide 95Slide 96Slide 97Slide 98Slide 99Slide 100Slide 101Slide 102Slide 103Slide 104Slide 105Slide 106Slide 107Slide 108Slide 109Slide 110Slide 111Slide 112Slide 113Slide 114Slide 115Slide 116Slide 117Slide 118Slide 119Slide 120Slide 121Slide 122Slide 123Slide 124Slide 125Slide 126Slide 127Slide 128Slide 129Slide 130Slide 131Slide 132Slide 133Slide 134Slide 135Slide 136Slide 137Slide 138Slide 139Slide 140Slide 141Slide 142Slide 143Slide 144Slide 145Slide 146Slide 147Slide 148Slide 149Slide 150Slide 151Slide 152Slide 153Slide 154Slide 155Slide 156Slide 157Slide 158Slide 159Slide 160Slide 161BIO 325 – GeneticsGenetic Linkage and Mapping in EukaryotesOf all that is good, sublimity is supreme. Succeeding is the coming together of all that is beautiful. Furtherance is the agreement of all that is just. Perseverance is the foundation of all actions.I ChingStatement: Chromosomes consist of more than one gene, typically many hundreds to a few thousand. Linkage and Crossing OverStatement: Chromosomes consist of more than one gene, typically many hundreds to a few thousand. What does the term synteny mean? Linkage and Crossing OverStatement: Chromosomes consist of more than one gene, typically many hundreds to a few thousand. What does the term synteny mean? What is genetic linkage and how does it influence inheritance patterns? Linkage and Crossing OverStatement: Chromosomes are sometimes called linkage groups, because the genes on a chromosome are physically connected to one another. Linkage and Crossing OverStatement: Chromosomes are sometimes called linkage groups, because the genes on a chromosome are physically connected to one another. What are the linkage groups in humans? Linkage and Crossing OverWhen geneticists follow traits they rely upon dihybrid (two-character) and trihybrid (three-character) crosses. Linkage and Crossing OverWhat is the result of genetic recombination (crossing over)? Linkage and Crossing OverWhat is the result of genetic recombination (crossing over)?What do we call cells that contain the new allelic combinations? Linkage and Crossing OverWhat is the result of genetic recombination (crossing over)?What do we call cells that contain the new allelic combinations?What do we call cells that contain the original combination of alleles? Linkage and Crossing OverWhat does this diagram show? Linkage and Crossing OverWhat does this diagram show? What would you expect to see in F2 if the genes were located on separate chromosomes? Linkage and Crossing OverLinkage and Crossing OverOops, what happened? Linkage and Crossing OverThe first direct evidence that different genes are physically located on the same chromosome was provided by Thomas Hunt Morgan, who studied X-linked patterns of inheritance in Drosophila. We will not cover the details of his work. Linkage and Crossing OverCreighton and McClintock are responsible for providing the first direct evidence that crossing over is associated with genetic recombination. We will not go into the details of their work.Linkage and Crossing OverGenetic Mapping in Plants and AnimalsStatement: Genetic mapping determines the linear order of genes on a chromosome and the separation of those genes on the chromosome. Genes have a specific place on a chromosome, called a locus. Genetic Mapping in Plants and AnimalsStatement: Genetic mapping determines the linear order of genes on a chromosome and the separation of those genes on the chromosome. Genes have a specific place on a chromosome, called a locus. Why is genetic mapping important?Genetic Mapping in Plants and AnimalsThe linear order of genes on a chromosome is called a genetic linkage map. Genetic Mapping in Plants and AnimalsWhat do we mean by the frequency of recombination between two genes?Genetic Mapping in Plants and AnimalsWhat do we mean by the frequency of recombination between two genes?How does recombination frequency correlate with their map distance along a chromosome?Genetic Mapping in Plants and AnimalsTestcrosses typically involve an individual that is heterozygous