Human Genetic Variation Slides Flashcards
What is our genome?
A complete set of genetic instructions
What is our genome required to do?
It is required to build an organism, to grow and develop, to function and react to our environment
How is our genome packaged?
Chromosomes
-Packaged into coiled linear strands of DNA
How many times is Unique DNA present in our genomes?
Once or a few times
What 6 things does Unique DNA include?
- Protein-coding genes
- Pseudogenes
- Promoters
- Introns
- Regulatory sequences
- Non-coding DNA
What are the three types of Repetitive DNA?
- Highly repetitive (centromere and telomere)
- Tandem repeats (Microsatellites, Minisatellites, rRNA genes)
- Interspersed repeats (tRNA genes, transposons)
Do we know the function of a large number of protein-encoding genes?
No, a large number is unknown
What 3 things are non-coding regulatory regions?
- Promoters
- Introns - splice enhancers and silencers
- 5’UTR and 3’UTRs
Pseudogenes
Regions of the genome that contain defective copies of genes
What is a Gene Family?
Genes that show a large amount of similarity at the nucleotide and protein level and thus, provide a similar function
How much of the genome is repetitive DNA?
60%
Satellite DNA
Different density
more GC content
How can you separate Satellite DNA?
Centrifugation through a CsCl gradient
based on density
Transposable elements
DNA elements that move around the genome
Genetic variation
How much are we identical?
99.9%
What is the difference b/w any two unrelated individuals?
0.1%
What is the most common type of variation?
Single nucleotide variant (SNV)
or single nucleotide polymorphism (SNP)
Insertion/ Deletion (Indels)
aka deletion insertion polymorphism (DIPs)
How do insertion/deletions result?
Errors in DNA replication, recombination, and repair
How do coding indels alter the reading frame?
If not a multiple of 3
Simple Sequence Repeats (SSRs)
Microsatellite repeat, short tandem repeats
Where are SSRs?
Dispersed throughout the genome
Minisatellites
Larger # of nucleotides per repeat unit
How to SSRs and STRs occur?
Strand slippage
Copy number variation (CNV)
AKA copy number polymorphism (CNP)
How many copies in CNV?
0-6
most often 1-3
