dna barcoding

DNA barcoding is a technique in which species identification is performed by using DNA sequences from a small fragment of the genome, with the aim of contributing to a wide range of ecological and conservation studies in which traditional taxonomic identification is not practical.

1. DNA BARCODING VEENA P KUMAR MSC SCHOOL OF BIOSCIENCES MGU veena 1

2. WHAT?? DNA barcoding is a technique in which species identification is performed by using DNA sequences from a small fragment of the genome, with the aim of contributing to a wide range of ecological and conservation studies in which traditional taxonomic identification is not practical. Short DNA sequences are called as DNA barcodes- ranging from 400- 800 bp . veena 2

3. The birth of DNA barcoding The use of DNA sequences for species identification has a long history . But it received significant attention only after it was formally proposed as ‘‘DNA barcoding’’ in 2003. veena 3

4. Dr. Paul D.N. Hebert- Father of DNA barcoding veena 4

5. Successful DNA barcode Short enough to be quickly sequenced Easily identified in all species of organisms . Variable enough to provide a unique sequence for each species Size of sequence : 600 – 700 bp Universality  veena 5

6. Which gene frgments ? veena 6

7. Sequencing can be done by a single organelle region Approximately ~650-bp sequences - C-terminal fragment of the mitochondrial gene named cytochrome oxidase subunit I (COI) has been proposed as universal marker for species level identification in several animal group. Barcodes ( mtDNA ) have become one of the most contentious and animated issues in the application of genetic information to global biodiversity assessment and species identification. veena 7

8. Why COI ? Mutation rate is fast. standard region enough to distinguish closely related species. lack insertions or deletions. Greater differences among species Copy number. (100-10,000 ) . Relatively few differences within species. Absence of introns. veena 8

9. DNA Barcoding in microbes 1.5 million species of fungi exist, but 10% are formally described . Variously used barcode, 400- to 600-bp region of the nuclear large ribosomal subunit , the internal transcribed spacer (ITS) gene sequences. Partial elongation factor 1- (EF-1) sequences focused on species of Penicillium subgenus Penicillium ( Trichocomaceae , Eurotiales , Eurotiomycetes , Ascomycota) veena 9

10. DNA barcode for plants Compared the performance of 7 leading candidate plastid DNA regions ( atpF – atpH spacer, matK gene, rbcL gene, rpoB gene, rpoC1 gene, psbK – psbI spacer, and trnH – psbA spacer) Assessments of recoverability, sequence quality, and levels of species discrimination, they recommended the 2-locus combination of rbcL+matK as the plant barcode.  veena 10

11. DNA BARCODING PROCESS veena 11

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13. IBOL – International Barcode of Life Largest biodiversity genomics initiative From 25 nations Scientists are working together to construct DNA barcode reference library First phase of operations (2010-2015) - barcode five million specimens representing 500,000 species. veena 13

14. CBOL – Consortium for the Barcode of Life International initiative (2004) . To develop DNA barcoding as a global standard for the identification of biological species . 200 Member Organizations from 50 countries . ECBOL - EUROPEAN CONSORTIUM FOR THE BARCODE OF LIFE Established as part of the research infrastructure efforts of EDIT, the European Distributed Institute of Taxonomy. veena 14

15.   CCBD – Canadian centre for DNA Barcoding Largest 'barcode factory', generating hundreds of thousands of data records per year Training barcode researchers from around the world. veena 15

16. APPLICATIONS • Protection of Endangered Species ( Conservation ) • Identifying Agricultural pest • Water quality testing • Identification of all life stages, eggs, larvae, nymphs, pupa, adults • Identification of fragments or products of organisms • Identification of stomach contents, trace ecological food-chains • Food control • Customs control veena 16

17. • Invasive species control • Disease vector control • Agriculture • Forestry • Education veena 17

18. THE FUTURE Data in seconds to minutes Link to reference database A taxonomic GPS Usable by non- specialists. veena 18

19. THANK YOU… veena 19