Genetic Mapping Flashcards
Linkage Map
A genetic map of a species or experimental population that shows the position of the known genes or genetic markers relative to one another.
Recombination
The act of recombining.
Rearrangement of genetic material (e.g crossing over in chromosomes)
Genetic Mapping
- Isolate a gene
Provides firm evidence that a disease transmitted from parent to child is linked to to one or more genes
provides clues as to which c/some contains the gene and where it lies on that c/some
Hemophilia Gene
The function of the wild-type hemophilia A gene is to produce a normal clotting factor, and mutations that inactivate this factor, produce hemophilia A.
Blood-clotting cascade
Enzyme events
Formation of a clot
Blood Tests
Can determine whether an active form of each factor involved in the clotting cascade is present.
Determine amino acid sequence
- Purify factor 8
- Obtain amino acid sequence.
- Reverse translation into coding sequence.
- Synthesize degenerate oligonucleotides
- Probe library
- Find factor 8 clone
- Structure of gene as determined from clone
Genomic Library
A collection of DNA clones that carry a representative copy of every DNA sequence in the genome of a particular organism.
Crossing Over
Can re assort alleles
Sister chromatids of one pair of c/somes crosses over with a sister chromatid from another pair of homologous c/somes
Linked Genes
Do not assort independently in meiosis.
usually inherited together when chromosomes are packaged into a gamete
Do not produce typical Mendelian ratios
Frequency of Recombination
The correlation between crossover frequency and gen distance is used to construct LINEAGE MAPS
If genes are far apart, crossing over is MORE likely to happen.
If genes are close together, genes are less likely to cross over
Location of CFTR gene
located on 7q31.2
Why are genetic maps useful?
- Understand the overall complexity and genetic organisation of a particular species
- Help molecular geneticists to clone genes
- Improve our understanding of the evolutionary relationships among different species
- Diagnosis inherited human diseases
- Help predict the the likelihood that a couple will produce children with certain inherited diseases
- Helpful info for improving agri important strains through selective breeding programs
Linkage maps
Is a diagram indicating the relative distance between genes
and estimates the relative distance between linked genes based on the likelihood that crossing over will occur between them.
Linkage Maps
Map unit = number of recombinant offspring/ total number of offspring x 100
1% = 1 map unit = 1 centimorgan (cM)
