LIFESCI 4 Lecture Notes - Lecture 17: Population Genetics, Panmixia, Genotype Frequency
LIFESCI 4 - Lecture 17 - Population Genetics
Microsatellites (STR)
- Using PCR, can still spot difference between homozygous and heterozygous
Minisatellites - Variable Number Tandem Repeats (VNTRs)
- 1 molecular marker → more number of alleles
- To detect alleles, can design probe for PCR → amplify variable regions through the
genome
- Look at combination of different markers
Population Genetics
- Look at population as a whole
- Help calculate risk for certain diseases
- Gives framework for understanding gene flow, disease risk, evolution at the population
level
Hardy Weinberg Equilibrium
→
There is no change in allele frequency
1. Large size population
2. Random mating
3. No migration
4. No mutation
5. No selection
- When there is evolution, there is no equilibrium → allele frequency will change when
there is evolution and is no longer predictable
- HW equations:
-p+q= 1
-pqp2+2 +q2= 1
MN Blood Group and HWE
- From allele frequency → can predict genotype frequencies
- Homozygous = MM and NN
- heterozygous = MN
Clicker 1:
Explanation:
- *if the population is in equilibrium → then the frequencies can be predicted
- Curly hair (16/100) = 6%q2= 1
-.4 and p.6 since p q= 0 = 0 + q= 1
- Heterozygous = 2pq = 2 (0.4) (0.6) = 0.48
Document Summary
Lifesci 4 - lecture 17 - population genetics. Using pcr, can still spot difference between homozygous and heterozygous. 1 molecular marker more number of alleles. To detect alleles, can design probe for pcr amplify variable regions through the genome. Gives framework for understanding gene flow, disease risk, evolution at the population level. Hardy weinberg equilibrium there is no change in allele frequency: large size population, random mating, no migration, no mutation, no selection. When there is evolution, there is no equilibrium allele frequency will change when there is evolution and is no longer predictable. Hw equations: p + q = 1 p2 + 2 pq. From allele frequency can predict genotype frequencies. Homozygous = mm and nn heterozygous = mn. *if the population is in equilibrium then the frequencies can be predicted. Heterozygous = 2pq = 2 (0. 4) (0. 6) = 0. 48. Must be told that the population is in equilibrium. 1 out of 3600 births are affected by cystic fibrosis.
