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FDA Assessment of DNA BarCoding for Species Identification of Fish Part One: The Potential Use of DNA Barcodes in Regulatory Science Applications of the Regulatory Fish Encyclopedia. Haile Yancy, Ph. D. U.S. FDA, Center for Veterinary Medicine, Office of Research.
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FDA Assessment of DNA BarCoding for Species Identification of FishPart One: The Potential Use of DNA Barcodes in Regulatory Science Applications of the Regulatory Fish Encyclopedia Haile Yancy, Ph. D. U.S. FDA, Center for Veterinary Medicine, Office of Research
The U.S. Food and Drug Administration (FDA) is responsible for protecting the public health by assuring the safety, efficacy, and security of food, human and veterinary drugs, biological products, medical devices, cosmetics, and products that emit radiation.
Center for Veterinary Medicine (CVM) is responsible for regulating, drugs, devices, feeds and feed additives given to over one hundred million companion animals, plus millions of poultry, cattle, swine, and minor animal species.
A DNA barcode is a short gene sequence used to identify species taken from a standard position in the genome
The Barcoding Process Specimen or Tissue Sample DNA Barcode PCR COI Sequence COI Extract DNA
Barcoding ProjectGoals and Objectives • Develop proficient protocols to extract, amplify, and sequence DNA to develop barcodes • To create DNA barcodes of targeted species of FDA’s interest
Regulatory Fish Encyclopedia (RFE) • The Regulatory Fish Encyclopedia (RFE) is a compilation of data in several formats that assists with the accurate identification of fish species • It was developed by FDA's RFE Team to help federal, state, and local officials and purchasers of seafood to identify species substitution and economic deception in the marketplace • http://www.cfsan.fda.gov
Regulatory Fish Encyclopedia (RFE) • Includes 94 commercially relevant fish for sale in the U.S. market • Visual comparison • Scanned digital images (whole fish and their market form) • Biochemical comparison • Isoelectric focusing (IEF)
Isoelectric Focusing(IEF) Protein Fingerprint Isoelectric focusing protein patterns for the pH range 3-10 for fresh, frozen, uncooked seafood based on AOAC 980.16
Problems with IEF Identification • Proteins • Sample condition • Will not work on denatured samples (cooked/neglected) • Sample preparation • Uses Association of Official Analytical Chemists (AOAC) validated method, but control samples are becoming exhausted • Different platforms • Inconsistent gel patterns
CVM’s Proposed Supplement to the RFE • To create barcodes for 94 fish contained in the RFE • Replace the restriction fragment length polymorphism (RFLP) DNA information or to create barcode data link
FISH-BOL • Dr. Paul Hebert and Dr. Bob Hanner Biodiversity Institute of Ontario, University of Guelph • Established June 2005 • 4,189 species barcoded • 21,981 barcodes
FISH-BOL • FDA RFE project • 179 specimens • 172 barcodes (sequences) • 73 species • Blind Sample Test • 60 samples were tested • 60/60 were identified correctly
PCR product ~650 bp PCR product ~350-250 bp PCR product ~250- 50 bp
Assay Development • Microarray Assay • 40-80k species in single assay • Ability to analyze cooked, processed, or mixed samples • Real- Time PCR Assay • Develop assay in 2-3 days • 3-4 species in single assay • Ability to analyze cooked, processed, or mixed samples • Results in ~1 hour
Tuna Mixed Sample (tuna/catfish)
Tuna Ch. Catfish Blue Catfish Allele ID Fish Sample Oligo Extract DNA ………………………………………….......………………………………………..………………………………………… Create Zoo Chip Label HYB ……………………………………………………………………………………………………………………………………… Identify Species (Tuna and Ch. Catfish)
Allele ID • Allele ID aligns sequences of different species to identify unique regions • Species specific primers and probes are designed based on differences in sequence • Taxa specific primers and probes can also be designed
5’ 3’ 5’ 5’ 5’ 3’ 3’ 3’ 1 2 3 4 5 Designing Probes from the COI Gene Generally probes are designed at a specific place along a gene sequence Available DNA of cooked, processed, or degraded sample Several Probes Designed Along Span of Gene 45-55 nucleotides in length 5
Negative Negative (Spotting Solution Residues) Positive Criteria for Analyzing Microarray Slides 1. Color of spots (specificity) 2. Ratio of detection (red) to background (green) fluorescence above 2.0 (sensitivity)
Tuna DNA with Tuna Probes Ch. Catfish DNA with Tuna Probes Great Barracuda DNA with Tuna Probes Rainbow Trout DNA with Tuna Probes Blue Catfish DNA with Tuna Probes Microarray results: Binding of DNA to Tuna Probes Fluorescence of Tuna DNA
Binding of DNA to Rainbow Trout Probes Channel Catfish DNA with Rainbow Trout probes Great Barracuda DNA with Rainbow Trout probes Blue Catfish DNA with Rainbow Trout probes Fluorescence of Rainbow Trout DNA Rainbow Trout DNA with Rainbow Trout probes
Real- Time PCR Assay • Allele ID • Aligned RFE and puffer fish barcode sequences • Created three Taqman® probes that detected all species of puffer fish contained in the BOLD database • PU016 • PU050 • PU038
Pufferfish Assay Methods • Extract DNA • Taqman® RT-PCR Protocol • 95°C: 2 minutes • 50 cycles • 95°C 15 sec. Denaturation • 60°C 30 sec. Annealing and Extension • Analyze Results
Optimization of Pufferfish Primers Pufferfish Primer PU016: Ct=25.44 Pufferfish Primer PU050: Ct=25.5 Pufferfish Primer PU038: Ct=42.7
Pufferfish Primer PU016 Specificity Figure 1. Primer PU016 was tested against 16 other fish species closely related to pufferfish to determine specificity. All samples came up negative
Known Pufferfish Samples with Primer PU016 Left: Florida Southern Puffer: Ct=22.84 Right: Florida Bandtail Puffer: Ct=30.7 Left: Florida Checkered Puffer: Ct=41.54
Cooked Fish from Soup Figure 1. Cooked puffer sample from the soup that caused the illnesses. Primer PU016 was used. Ct=41.26
Pufferfish Assay • PU016 • PU050 • PU038
Next Step of Assay Validation • FDA is in the process of submitting the assay for AOAC® Peer-Verified Method • After validation, the pufferfish assay will be used by Office Of Regulatory Affairs (ORA) labs
A Regulatory Tool for the Third Millennium
CVM Dr. Marleen Wekell Dr. Russell Frobish Jewell Washington Jacquline Mason Michelle LeCluyse CFSAN Dr. Fred Fry Spring Randolph Dr. Jon Deeds CONSORTIUM FOR THE BARCODE OF LIFE Dr. Paul Hebert Tyler Zemlak Dr. Scott Miller Dr. David Schindel Dr. Bob Hanner Acknowledgements Seafood Products Research Center Pacific Regional Laboratory – Northwest Dr. Rick Long Dr. Cindy Wu Jim Barnett Ngoc-Lan Nguyen Dr. Michelle Moore Dr. Bradley Tenge
Thank You Questions?