BIOC51H3 Lecture 10: BGYB51H3 Lecture 10 Notes Oct 13
11 Aug 2010
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BGYB51H3 Lecture 10 Notes
-comparing mitochondrial DNA can be used to determine mutations/locus/generation
-mitochondrial DNA is more susceptible to errors and mutations than nuclear DNA
-mutation rates are variable because they depend on the accuracy of DNA polymerase
-DNA polymerase varies due to allelic variation and the fact that it is a synthesized protein
-mutation is a side effect of rapid cell division, which is a trade off of DNA replication
-high mutation rates are favoured in novel environments
-low mutation rates are favoured in similar and constant environments
-mutation strain is more successful in early infection due to novel environment
-when wild type strain adapts to novel environment, mutation advantage stops
-wild types eventually slow mutation to reach high level of fitness
-any factor that tries to reduce variation is a selective agent
-in most cases, strains of wild type and mutator bacteria will compete in a novel environment
for survival
-mutators are favoured in a new environment in competition with a wild type bacteria even
when initial inoculation gives a numerical advantage to wild types
-rapid DNA replication is beneficial to disease organisms
-gene duplication is one source for new genes during meiosis
- paralagous genes are duplicated genes may accumulate mutations that can acquire new
functional effects
-paralogous genes derive from a common ancestor
-orthologous genes are duplicated genes can result in the separation of lineages
-uµ]}v}v[µ]Pv](]vZvP]n allele frequencies
-synapomorphies are homologous traits that define a particular lineage
-neutral mutations result in divergence of lineages and can be analyzed by a molecular clock
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Document Summary
Comparing mitochondrial dna can be used to determine mutations/locus/generation. Mitochondrial dna is more susceptible to errors and mutations than nuclear dna. Mutation rates are variable because they depend on the accuracy of dna polymerase. Dna polymerase varies due to allelic variation and the fact that it is a synthesized protein. Mutation is a side effect of rapid cell division, which is a trade off of dna replication. High mutation rates are favoured in novel environments. Low mutation rates are favoured in similar and constant environments. Mutation strain is more successful in early infection due to novel environment. When wild type strain adapts to novel environment, mutation advantage stops. Wild types eventually slow mutation to reach high level of fitness. Any factor that tries to reduce variation is a selective agent. In most cases, strains of wild type and mutator bacteria will compete in a novel environment for survival.
