Solving mysteries using DNA technology DNA Detectives Solving mysteries using DNA technology Presented by Dawn Crisologo and Justin Guce Biology Unit, PSHS – Main Campus, Diliman, Quezon City http://www.virginmedia.com/microsites/technology/slideshow/vm-tech-gallery/civilliberties/img_5.jpg

THE SCENE DNA fingerprinting in the Biology classroom Basic features of DNA Restriction enzymes How DNA fingerprinting works Simulation activity Real world and scientific applications Ethical issues

Why teach DNA fingerprinting? Extension activity to lessons on the molecular basis of inheritance Real-world connections Link to biotechnology careers and industries Integration of science and technology with society Images from http://www.csi-pi.net, http://www.fbs.leeds.ac.uk/, and http://www1.istockphoto.com/

DNA 101: Basic features http://genetic-identity.com/Basic_Genetics/DNA-of-life.jpg

Restriction enzymes named after bacterial genus, species, strain, and type e.g. EcoR1 Genus: Escherichia Species: coli Strain: R recognize specific base sequences in DNA and cut DNA at these recognition sites e.g. GAATTC Restriction site Palindrome Fragment 2 Fragment 1

Organism from which derived Target sequence (cut at *) 5' -->3' Enzyme Organism from which derived Target sequence (cut at *) 5' -->3' Ava I Anabaena variabilis C* C/T C G A/G G Bam HI Bacillus amyloliquefaciens G* G A T C C Bgl II Bacillus globigii A* G A T C T Eco RI Escherichia coli RY 13 G* A A T T C Eco RII Escherichia coli R245 * C C A/T G G Hae III Haemophilus aegyptius G G * C C Hha I Haemophilus haemolyticus G C G * C Hind III Haemophilus inflenzae Rd A* A G C T T Hpa I Haemophilus parainflenzae G T T * A A C Kpn I Klebsiella pneumoniae G G T A C * C Mbo I Moraxella bovis *G A T C Pst I Providencia stuartii C T G C A * G Sma I Serratia marcescens C C C * G G G SstI Streptomyces stanford G A G C T * C Sal I Streptomyces albus G G * T C G A C Taq I Thermophilus aquaticus T * C G A Xma I Xanthamonas malvacearum C * C C G G G

DNA Fingerprinting 101 technique used to distinguish between individuals of the same species using only DNA samples relies on the ability of restriction enzymes to cut DNA from different individuals into fragments of different lengths invented by Alec Jeffreys of the University of Leicester (1985) Images from http://evolution.berkeley.edu/evolibrary/images/news/ and www.telegraph.co.uk

Uniquely you Sequence repeats in the human genome Variable Number of Tandem Repeats (VNTR) Amplified Fragment Length Polymorphisms (AmpFLP) Short Tandem Repeats (STR) 10 – 13 sites needed for criminal investigations 4 sites to establish parentage Single Nucleotide Polymorphisms (SNP) Y-STR analysis Mitochondrial DNA (mtDNA) analysis

DNA Fingerprinting Procedures DNA extraction and isolation Cutting by restriction enzymes Loading of samples into the electrophoretic gel Running samples through the gel Visualization of bands Analysis and comparison of profiles obtained DNA Fingerprinting Procedures Images from www.virtualsciencefair.org, images.jupiterimages.com, www.flutrackers.com, www.topac.com, www.bioinformatics.vg, and www.scq.ubc.ca

Real-world applications Crime scene investigations Genealogy Paternity-testing Animal-relatedness Anthropology studies Disease-causing organisms Food identification Human remains Monitoring transplants

Some ethical issues Fairness in the use of genetic information Privacy and confidentiality of genetic information Psychological impact and stigmatization due to an individual's genetic differences Clinical issues involving implementation of standards and quality-control measures in testing Uncertainties associated with gene tests for diseases