FINALS: DNA POLYMORPHISMS AND HUMAN ID Flashcards
(44 cards)
- Variations of DNA sequences (ranging
from a single base pair to thousands of
base pairs) that are shared by 1%-2%
or more of a given population
POLYMORPHISMS
STRUCTURE:
Single-nucleotide differences (1-bp), may occur in gene-coding
regions or in intergenic sequences
DETECTION METHODS;
Sequencing, other
SINGLE NUCLEOTIDE POLYMORPHISMS (SNPs)
STRUCTURE:
Highly repeated sequences (6-8kbp in length), containing RNA
polymerase promoters & open reading frames
DETECTION METHODS;
Sequencing
LONG INTERSPERSED NUCLEOTIDE ELEMENTS (LINES)
STRUCTURE:
Highly repeated sequences approximately 0.3
kbp in length, including Alu elements
DETECTION METHODS:
Sequencing
SHORT INTERSPERSED NUCLEOTIDE ELEMENTS (SINES)
STRUCTURE:
Head-to-tail repeats of DNA sequences with
(LESS THAN) <10-bp repeat units
DETECTION METHODS;
PCR
SHORT TANDEM REPEATS (STRs)
STRUCTURE:
Head-to-tail repeats in DNA with 10-50-bp repeat units
DETECTION METHODS;
Southern Blot, PCR
VARIABLE - NUMBER TANDEM REPEATS (VNTRs)
STRUCTURE:
A sequence variation that results in CREATING, DESTROYING
, or MOVING a restriction site
DETECTION METHODS;
Southern Blot
RESTRICTION FRAGMENT LENGTH POLYMORPHISMS (RFLPs)
RFLP IS USED TO FORM PATTERN BY?
BREAKING DOWN DNA
- DIFFERENCES IN SIZE & NUMBER of FRAGMENTS generated by restriction enzyme digestion of DNA
Nucleotide changes may also destroy, change, or create restriction enzymes sites, altering the number of fragments.
RESTRICTION FRAGMENT LENGTH
POLYMORPHISMS (RFLPs)
RFLP typing in humans required the use
of
Southern blot technique
The ________of the collection of polymorphisms in each individual is the BASIS FOR HUMAN ID AT THE DNA LEVEL.
uniqueness
RFLP protocols for human ID:
North American labs use?
Haelll restriction enzyme
(Haemophilus aegyptius)
RFLP protocols for human ID:
European labs use?
Hinfl restriction enzyme
(Haemophilus influenzae strain Rd.)
A. GENETIC MAPPING WITH RFLPs
Polymorphisms can be used as __________ in the genome to determine the location of other genes
landmarks/markers
A. GENETIC MAPPING WITH RFLPs
More frequently a particular polymorphism is present in persons with a disease phenotype =
MORE LIKELY THE AFFECTED GENE IS LOCATED CLOSE TO THE POLYMORPHISM
❖ Inherited breast cancer:
RFLP location:
17q21
❖ Inherited breast cancer:
_____: mapped to this position
BRCA1 gene
- Fragment sizes of an individual are a combination of those from each parent
RFLP & PARENTAGE TESTING
alleles/fragment sizes of
the child & the mother are analyzed
Paternity test
provide the remaining alleles/fragments (inclusion)
Alleged fathers (AFs)
C. HUMAN ID USING RFLPS
- 1st genetic tool for human ID:
ABO blood group antigens
C. HUMAN ID USING RFLPS
- 1st human DNA profiling/fingerprinting
system:
UK Forensic Science Service (1985) using Sir Alec Jeffrey’s Southern blot multiple-locus probe (MLP)-RFLP system
- Single-locus probe (SLP) (1990) in Europe & N. America
RFLP Southern blot technique:
(how much/many?)
100 ng to 1 ug of DNA (1-20 kbp)
- HEAD-TO-TAIL repeats of DNA sequences with <10-bp repeat units
- Detection method: PCR
SHORT TANDEM REPEATS (STRS)
