Term
| What types of repeat units are there? |
|
Definition
Mononucleotide
Micro satellites
minisatellites
satellites
telomeres
rDNA arrays |
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Term
| By what methods do tandem repeats tend to change? |
|
Definition
change in copy number (usually) via:
de novo synthesis
unequal crossover
unequal sister chromatid exchange
unequal gene conversion
replication/repair slippage |
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Term
| What effect do the mutations that change tandem repeat copy number have on variation? |
|
Definition
|
|
Term
| What are microsatellites useful for? |
|
Definition
| Linkage mapping and individual indentification |
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Term
| Where do minisatellites cluster? |
|
Definition
|
|
Term
| What structure does human mtDNA have? |
|
Definition
|
|
Term
| How is the mtDNA 'economical'? |
|
Definition
| Densely packed, little non-coding DNA between genes, sometimes they even ovelap |
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Term
| What is the D-loop region? |
|
Definition
| The only extensive non-coding DNA in the mtDNA - contains heavy strand origin and promoters - high level of substititional polymorphism |
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Term
|
Definition
| Leber's hereditary optic neuropathy - 90% of sufferers have missense mutations in ND1 - in mtDNA- Affects optic nerve, leading to loss of vision as an adult - maternally inherited, incomplete penetrance |
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Term
| Why is mtDNA maternally inherited? |
|
Definition
in egg - 10^5 mitochondria
in sperm - 50-100
Sheer numbers
Paternal mtDNA can be seen in the zygote, but later, even very deep resequencing finds none - suggests active elimination of paternal mtDNA |
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Term
|
Definition
| A mix of different mtDNA sequences |
|
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Term
| What happens when a new mutation arises in mtDNA? |
|
Definition
| Initially present at one copy - must pass through a phase of heteroplasmy before fixation or elimination |
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|
Term
| What is the reason for the seemingly high rate of mitochondrial mutations? |
|
Definition
| Detection of mutations that will not persist due to election, mutations found at highly mutable positions |
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Term
|
Definition
| Nuclear insertions of mtDNA - cause issues with sequencing |
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Term
|
Definition
| Gene linked to fertility-strong selection on Y chromosome |
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Term
|
Definition
| On the Y chromosome, just past the boundary where Y and X are no longer homologous |
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Term
| What reasons could there be for low diversity in Y chromosomes? |
|
Definition
Lower Ne
Selective sweeps
Link to low male migration |
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|
Term
| What polymorphisms are found on Y? |
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Definition
| satellites, minisatellites, indel polymorphisms |
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Term
| What occurred in the British surname/Y chromosome experriment? |
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Definition
| Sharing surname = increased probability of sharing Y haplotype, rarer surnames more likely |
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