CHAPTER 10 MB Flashcards
Are variations of DNA sequences that are shared by a certain percentage of a population. These sequences range from a single base pair to thousands of base pairs.
POLYMORPHISMS
The probability of polymorphic DNA in humans is great due to the relatively large size of
the human genome, ___ of which does not code for genes.
98%
May occur in gene-coding regions or in intergenic sequences
SINGLE NUCLEOTIDE POLYMORPHISMS
Polymorphisms are more frequent in some areas of the genome than in others. The _________ locus is a familiar example of a highly polymorphic regions of human DNA
- The variable nucleotide sequences in this locus code for _____ that establish self-identity of the immune system.
human leukocyte antigen (HLA) ; peptides
Are highly repeated sequences, 6 to 8 kbp in length, that contain RNA polymerase promoters and open reading frames related to the reverse transcriptase of retroviruses
Long Interspersed Nucleotide Elements (LINEs)
0.3 kbp in size, are present in over 1,000,000 copies per genome.
Short Interspersed Nucleotide Elements (SINEs)
Short Interspersed Nucleotide Elements (SINEs) include __________ - named for harboring recognition sites for the Alu(I) restriction
enzyme.
Alu elements
- There are well in excess of 1 million Alu elements, accounting for almost __________
- The majority of transcribed genes contain Alu elements in their _____
11% of the human genome ; introns
Alu elements have _______ and ________, which can become activated through the accumulation of mutations and lead to alternative splicing of RNAs or premature termination of translation.
cryptic splice and polyadenylation sites
LINEs and SINEs are also known as ______ or _________. They are copied and spread by recombination and reverse transcription and may be responsible for the formation of _______
mobile elements ; transposable elements ; pseudogenes
Shorter blocks of repeated sequences also undergo expansion or shrinkage through generations.
SHORT TANDEM REPEATS (STRs) and VARIABLE-NUMBER TANDEM REPEATS (VNTRs)
SNPs, larger sequence variants, and tandem repeats can be detected by observing changes in the restriction map of a DNA region. Analysis of restriction fragments by Southern blot reveals _________
restriction fragment length polymorphisms (RFLPs).
Analysis of restriction fragments by Southern blot
RESTRICTION FRAGMENT LENGTH POLYMORPHISMS (RFLPs)
One or more nucleotide changes that affect the size of restriction enzyme products
RESTRICTION FRAGMENT LENGTH POLYMORPHISMS (RFLPs)
STRUCTURE: One or more nucleotide changes that affect the size of restriction enzyme products
DETECTION METHOD: SOUTHERN BLOT
RFLP - RESTRICTION FRAGMENT LENGTH POLYMORPHISMS
STRUCTURE: Repeats of 10–50 base sequences in tandem
DETECTION METHOD: SOUTHERN BLOT, PCR
VNTR - VARIABLE-NUMBER TANDEM REPEATS
STRUCTURE: Repeats of 1–10 base sequences in tandem
DETECTION METHOD: PCR
STR - SHORT TANDEM REPEATS
STRUCTURE: Alterations of a single nucleotide
DETECTION METHOD: SEQUENCING, OTHER
SNP - SINGLE NUCLEOTIDE POLYMORPHISMS
In RFLP typing, Original DNA targets used for ________, ___________, and __________.
gene mapping ; human identification ; parentage testing
Observed as differences in the sizes and number of fragments generated by restriction enzyme digestion of DNA
RFLP TYPING
__________ may also destroy, change, or create restriction enzyme sites, altering the number of fragments
Nucleotide changes
The first step in using RFLPs is ________________________________. Once the restriction map is known, the number and sizes of the restriction fragments of a test DNA region cut with restriction enzymes are compared with the number and sizes of fragments expected based on the restriction map
to construct a restriction enzyme map of the DNA region under investigation
___________ are detected by observing fragment numbers and sizes different from those expected from the reference restriction map.
Polymorphisms
RFLP typing in humans required the use of the
___________. DNA was cut with _______-, resolved by ________, and blotted to a _________.
Southern blot technique ; restriction enzymes ; gel electrophoresis ; membrane
Human beings are diploid with two copies of
every locus. In other words, each person has ____ alleles of each locus.
two
If these alleles are the same, the locus is ________; if the two alleles are different, the locus is ___________.
homozygous ; heterozygous
RFLP protocols for human identification in most North American laboratories used the restriction enzyme ____ for fragmentation of genomic DNA, Many European laboratories used the ______ enzyme.
HaeIII ; HinfI
_________ are used to determine the probability that an unknown gene is located close to a known marker in the genome.
Formal statistical methods
__________ used RFLP to map one of the genes mutated in inherited breast cancer.
Mary Claire King
A parentage test requires analysis of at least _______. The more loci tested, the higher the probability of positive identification of the father.
eight loci
The initial use of DNA as an identification tool relied on RFLP detectable by Southern blot. The first genetic tool used for human identification was the ____________. Although this type of analysis could be performed in a few minutes, the discrimination power was low.
ABO blood group antigens
The initial use of DNA as human identification tool relied on ______ detectable by Southern blot
RFLP
DNA Fingerprinting With RFLP
The first human DNA profiling system was introduced by the ____________ in 1985 using ______________ system
United Kingdom Forensic Science Service ; Sir Alec Jeffrey’s Southern blot multiple-locus probe (MLP) -RFLP
___________ system could take 5 to 7 days to yield clear results
P-based probe
RFLP is an example of a ____________ system in which the sizes of the fragments define alleles. Therefore, precise band sizing was critical to the accuracy of the results
continuous allele
__________, a British geneticist, first developed techniques for genetic profiling, or DNA fingerprinting, using RFLP to identify humans. The technique has been used in forensics and law enforcement to resolve paternity and immigration disputes. The method can also be applied to nonhuman species, for example, in wildlife population genetic
Professor Sir Alec John Jeffreys
The first commercial and validated typing test based on polymerase chain reaction (PCR) specifically for forensic use was the _________, now called ______, developed in 1986. This system could distinguish ___ DQA1 types
HLA DQ alpha system ; DQA1; 28
with the addition of the __________, the analyst could type five additional genetic markers.
Polymarker (PM) system
