Gene mapping Chapter 6
20.000 protein coding genes
Synteny: 2 or more genes located on the same chromosome and physically linked
Genetic linkage: genes close together transmit as a unit (inheritance)
Linkage group: Chromosomes that are linked together (22 autosomal, x, y)
Dihybrid cross: linkage between 2 genes on the same chromosome
Trihybrid cross: linkage between 3 genes on the same chromosome
Bivalent: structure during crossing over of homologous chromosomes
Chiasma: place of crossing over
Nonparental recombinant cells: genes that crossed over (not found in parental cell)
Hypothesis
-The genes are all on x chromosome
-Homologous x chromosomes can exchange pieces of chromosomes
-The further apart 2 genes are, the bigger the chance for crossing over
High frequency of parental phenotypes: genes are on same chromosome
Frequency of crossover phenotypes: tells us the distance between genes
Combination of different alleles in low frequency: means there is cross -over
Extremely low frequency: 2 crossover events meaning an allele is in the middle
EXAM!!!! (how can you find out if a gene is located in the middle?)
Gene mapping: to determine the order of linked genes along the same chromosome
- Overall complexity of a species
- Help clone genes
- Help understand evolution
- Diagnose/treat inherited diseases
- Predict inherited diseases
- Help improve agriculturally important strains
- distance between linked genes
- Percentage of recombinant offspring linked to distance
Map distance: recombinant offspring / tot number * 100
Mapunits or 1% recombination frequency
Locus: each gene has its own site within a chromosome
Mitotic recombination: new cells all have the recombination but 2 different fenotypes
Skip chi square and 6.4
20.000 protein coding genes
Synteny: 2 or more genes located on the same chromosome and physically linked
Genetic linkage: genes close together transmit as a unit (inheritance)
Linkage group: Chromosomes that are linked together (22 autosomal, x, y)
Dihybrid cross: linkage between 2 genes on the same chromosome
Trihybrid cross: linkage between 3 genes on the same chromosome
Bivalent: structure during crossing over of homologous chromosomes
Chiasma: place of crossing over
Nonparental recombinant cells: genes that crossed over (not found in parental cell)
Hypothesis
-The genes are all on x chromosome
-Homologous x chromosomes can exchange pieces of chromosomes
-The further apart 2 genes are, the bigger the chance for crossing over
High frequency of parental phenotypes: genes are on same chromosome
Frequency of crossover phenotypes: tells us the distance between genes
Combination of different alleles in low frequency: means there is cross -over
Extremely low frequency: 2 crossover events meaning an allele is in the middle
EXAM!!!! (how can you find out if a gene is located in the middle?)
Gene mapping: to determine the order of linked genes along the same chromosome
- Overall complexity of a species
- Help clone genes
- Help understand evolution
- Diagnose/treat inherited diseases
- Predict inherited diseases
- Help improve agriculturally important strains
- distance between linked genes
- Percentage of recombinant offspring linked to distance
Map distance: recombinant offspring / tot number * 100
Mapunits or 1% recombination frequency
Locus: each gene has its own site within a chromosome
Mitotic recombination: new cells all have the recombination but 2 different fenotypes
Skip chi square and 6.4
