First part of 206 Flashcards
HIV into Aids 3 phases
Acute, Chronic, AIDS
Acute phase
- retrovirus in immune cells with CD4
- Binds to CD4
- Fuses and releases DNA
- DNA splicing (into our DNA), transcription and translation of HIV mRNA
- Reassemble into new virions, bud into proteases, makes mature virus
Chronic phase
- dentritic cells capture virus
- present polypeptides to naive helper T cells
- Divide to produce activated helper T
- stimulate B cells to mature into plasma cells
- Make antibodies against virus
- Activate killer T cells to destroy infected host cells
- Recruit macrophages to destroy virions and infected host cells
AIDS
- Lots of immune cells trying to protect against HIV = More cells for HIV to infect!
- Compromised immune system so can’t fight off infections
How understanding evolution helps control HIV/AIDS
- need to stop viral reproduction w/o stopping regular cells
- Can stop: co-reception, fusion, reverse transcription or maturation
- Drug resistance evolves fast since reverse transcription=error prone
- New epitopes evolve faster than host
- viral pop gets more aggressive due to competition
- virus evolves new strains that can attach to diff co-receptors
- Can be controlled with 3 diff drugs taken CONSISTENTLY (just 80% of the time is the worst)
Patterns a unifying theory must explain (7)
- changes in traits w environmental changes
- results of artificial selection
- emerging infectious diseases
- vestigial organs
- homologous traits
- succession
- transitional forms
Evolution
Change in allele frequencies between generations
Natural selection
differences in lifetime reproductive success of individuals with different phenotypes
Evolution by natural selection 4 postulates
- Individuals within pop vary phenotypically
- phenotypic variation is at least partially heritable
- individuals vary in lifetime reproductive success
- Variation in survival/reproduction is nonrandom with respect to phenotype
What does natural selection and evolution act on
Natural selection acts on individuals and phenotypes/evolution occurs in populations and consists of changes in allele frequencies
What is standing variation
Multiple alleles at loci
3 types of quantitative analysis
- continuous
- discrete
- Meristic
Vp (variation of pop)=what
Vg+Ve+V(g x e)
heterozygosity = what
number of alleles/locus
Ve (phenotypic plasticity) example
- tanning in humans
V (g x e) (genetic variation in phenotypic plasticity) example
- how I burn easier than some people in the sun
V (g x e) generated 2 main ways
- Mutations
2. Recombination
Types of mutations (5)
- Point
- gene duplications
- chromosomal mutations
- chromosomal duplications
- epigenetic
3 statements of Hardy weinberg theory
- genotype and allele frequencies predicted from each other using binomial distributions
- Allele and genotype frequencices will not change between generations
- This is under certain assumptions
Formula of HW
(p+q)^2=p^2+2pq+q^2
5 HWE theorem assumptions + 1 new one
- No mutation
- Infinite population size
- Random mating
- No migration
- No selection
(No linkage)
Finite pop on genetic diversity
- sampling error
- genetic drift
- evolution but not adaptation due to drift
- smaller pop = hit harder by drift
- drift reduces genetic variation
- bottleneck
- founder effects
Bottleneck
severe short-term reduction in pop size
Founder effect
establishment of new population by small number of individuals
