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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. Tilapia Aquaculture. High-quality food fish; Easy to reproduce, breed and farm; Farming for freshwater and brackish water;
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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
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.
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.
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.
How Can DNA-based Technology be Helpful for Tilapia Farming?
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 it’s 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/
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 isolations from fin clip DNA Sequencing PCR Amplification
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.
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.)
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.
SSR Unique sequence Unique sequence SSR with 15 copies of CA repeats Microsatellite DNA Analysis CACACACACACACACACACACACACACA
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.