DNA-Based Identifications of Tilapia in Hawaii

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DNA-Based Identifications of Tilapia in Hawaii
Jinzeng Yang and Harry Ako
College of Tropical Agriculture and Human
Resources University of Hawaii at Manoa
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Tilapia Aquaculture

• High-quality food fish
• Easy to reproduce, breed and farm
• Farming for freshwater and brackish water
• Excellent species for aquaponics
• A potential growth area for Hawaii with
  groundwork having been laid in the marketing
  area.

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Challenges of Tilapia Farming in Hawaii
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The Goal and Objectives

• The long-term goal of the project is to have
  fast-growing tilapia for farmers in Hawaii.
• Main Objectives
• Identification of the tilapia strains and hybrids
  existing in the wild and captive populations by
  DNA barcoding method
• Successfully allow importation of fast growing
  strains or develop DNA-based testing tools for
  selection of high-growth tilapia by selectively
  breeding local tilapia resources.

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• What is DNA and genome?
• Permanent part of the body cells, inheritable
• Genome a whole collection of the DNA of a
  species
• Different species are made of different genomes
• Strains with one species have slightly different
  DNA sequences.

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How Can DNA-based Technology be Helpful for
Tilapia Farming?
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The PCR Song There was a time when to amplify
DNA, You had to grow tons and tons of tiny
cells. Then along came a guy named Dr. Kary
Mullis, Said you can amplify in vitro just as
well. Just mix your template with a buffer and
some primers, Nucleotides and polymerases,
too. Denaturing, annealing, and extending. Well
its amazing what heating and cooling and heating
will do. PCR, when you need to detect
mutations. PCR, when you need to recombine. PCR,
when you need to find out who the daddy mommy
is. PCR, when you need to solve a
crime. www.cnpg.com/video/flatfiles/539/
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PCR and DNA Sequencing

• PCR is a technology used to amplify genes of
  interest.
• Template DNA, primer, denaturing, annealing and
  extending.
• Sequencing amplified genes from fin clip.
• Each MBBE lab has about 4 PCR machines.

DNA Sequencing
PCR Amplification
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DNA Barcoding

• It is DNA sequence-based taxonomic method of
  species identification.
• A 648 base-pair region in the mitochondrial
  (maternal) cytochrome c oxidase 1 gene (COI) has
  been extensively studied. FISH-BOL database.
  Obtain sequences of known species as niloticus,
  mossambicus, aureus and so on.
• The DNA sequence COI can identify parents
  (mothers) of existing species in Hawaii,
  including niloticus.

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• Amplify and sequence DNA of available tilapia in
  Hawaii.
• If we have niloticus here already, DOA may let us
  import.
• If we have niloticus here already, we can reverse
  breed to get back a fast growing strain.
• (These methods have been used to identified
  mislabeled fillets.)

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Microsatellite DNA Marker

• Simple nucleotide repeat, very short,
  tandem-repeat sequences, such as
  ACACACACACAC-(AC)6
• Highly polymorphic- most individual animals are
  heterozygous at each locus this is because there
  is no selective pressure to maintain the
  sequences they are not translated.
• Genetics analysis DNA identification,
  marker-assisted selection, parental assignment.
  Useful to distinguish closely related organisms
  including siblings of same species.
• Can use this method in marker assisted breeding.

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Microsatellite DNA Analysis
CACACACACACACACACACACACACACA
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Plan of Work
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Summary

• Determination of genetic resources in Hawaii
• To allow importation of fast growing species
  since they may already be here or
• To back engineer to fast growing strains that
  originally got in
• To use microsatellite markers if there is a
  selected breeding program.
• Sponsored by CTSA.