DNA Typing

Types of polymorphic DNA sequences

• SNP = change in a —— base pair

• STR = short tandem repeats (——— bp)

• VNTR = variable number tandem repeats (—— bp)

• RFLP = restriction fragment length polymorphism

single, 1-8, 8-50

Single Nucleotide Polymorphisms

• ——— nucleotide polymorphism between DNA sequences

• Occur very ———

• Detected through ———, ———-, and —— —— analysis

• Applications = particular SNPs are associated with a ——- to develop a certain disease

single, frequently, microarrays, sequencing, melt curve, predisposition

Tandem Repeats

• islands of short sequences repeated all over the chromosome

  • The number of repeats ——- in each individual

  • The number of repeats is a measure of individual ———

    • ID is based on the —— of repeats, NOT the —— of the repeat

• Can be large or small repeats

  • Mini satellites (VNTRs)

    • ——— bp

    • Easier to distinguish since there is greater room for ———

    • Usually tested for using —— ——-

  • Microsatellites (STRs)

    • ——— bps

    • Usually tested for using ——-

vary, identity, number, sequence, 8-100, variation, southern blot, 1-7, PCR

Restriction length Polymorphisms

• Restriction fragment sizes are altered by changes in or between enzyme ——- sites

  • SNPs, VNTRs, point mutations, STRs, duplications, insertions, deletions can all cause RFLPs

  • RFLP is NOT a specific type of ——-, but rather a good mechanism at ——- polymorphisms

    • Any changes to a restriction site will change the —— and —— of fragments produced during a digestion

    • Performing RFLP will determine if there was an ———- or ———- of a restriction site

recognition, polymorphism, detecting, number and size, addition, elimination

Amelogenin locus

• This locus is NOT an ——-

• Used to differentiate ——- from ——-

  • Used for —— differentiation

• Homozygous X = ———

• heterozygous X = ——-

STR, males ,females, gender, female, male

Objectives of DNA typing

• to demonstrate the differences in DNA —— at specific polymorphic sites and use that to ——- and ——- individuals

• samples from the same individual should have the same exact ———- present = basis of identification

sequence, distinguish, identify, polymorphisms

Forensic DNA Typing

• Matching the criminal suspect DNA profile to the DNA found at the crime scene (——- an individual)

• Suspect profile must match —— to the number of ——— on the DNA found at the crime scene in order to consider a match

  • One mismatch = ———, even if there are other matches

• The power of discrimination increases with the more ——- profiled

identify, exactly, repeats, exclusion, loci

Paternity DNA Typing

• Find out if two or more people are biologically ——- (determine a ———)

• Child will NOT have an identical profile to the mother or father, but rather a ——- of both

  • All alleles from the child should match with either the ——- or ———

related, relationship, combination, mother, father

Methods for DNA Typing

• Southern blot

  • Use ———- of ——- for polymorphic sites

  • Used for —— products/repeats (——) and if material is sufficient

  • Can use a —— ——- ——- to test multiple loci at a time and develop a unique DNA profile called a ————- ————

• PCR

  • ——— of a polymorphic site using a pair of ——- located ——— of the polymorphic site

  • Used for ——- products (——) or if material is less/degraded

  • Can use ——- PCR to detect multiple loci at a time and develop a profile similar to a DNA fingerprint

  • Uses —— ——- to guesstimate the number of repeats in a product

hybridization ,probes, larger, VNTRs, multi locus probe, DNA fingerprint, amplification, primers, outside, smaller, STRs, multiplex, allelic ladders

Obligate paternal allele

• Alleles belonging to the child that are NOT shared with the ——-, and therefore MUST belong to the alleged ——— in order for inclusion to be determined

  • If a suspected father does not contain the OPA at ——— of more loci = ———-

mother, father, three, exclusion

Inclusion

• Means that the child-father relationship is ———

• two criteria

  • The alleged father shares ALL ——— with the child at three or more loci

  • A probability value of at least 99.99%

    • Equation determines how likely matches between alleged father and child could be due to ——- ——-

consistent, obligate paternal alleles, random chance

Exclusion

• When the child-father relationship is NOT ———

• When the father does NOT share all ——- with a child at ——- or more loci

  • 3 or more mismatches = ————

    • Probability of paternity would be calculated at 0.0%

• This is —— to determine than inclusion

consistent, obligate paternal alleles, three, exclusion, easier

Review how to interpret all forensic and paternity testing examples in week 6 - Did you it?

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