DNA BARCODING Meaning and
Definition
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DNA barcoding is a method used in biological taxonomy and biodiversity research that involves sequencing a specific gene fragment in the DNA of an organism to identify and differentiate species. The technique is based on the fact that different species possess unique DNA sequences, specifically in a gene region known as the mitochondrial cytochrome c oxidase subunit 1 (CO1) gene. By comparing the DNA barcode sequence of an unknown organism to a reference database of known barcode sequences, scientists can classify, identify, and catalogue species accurately and efficiently.
The DNA barcoding process involves five main steps: specimen collection, DNA extraction, amplification, sequencing, and analysis. First, a specimen is collected from the organism, such as a tissue sample or entire organism. Next, the DNA is extracted and purified from the collected specimen. The target gene region, CO1, is then amplified, or copied, multiple times using specific primers through Polymerase Chain Reaction (PCR). Once amplified, the DNA sequence in the target region is determined through sequencing methods. Finally, the obtained sequence is compared to a comprehensive barcode reference library or database to identify the species of the specimen.
DNA barcoding offers numerous advantages in species identification, such as its ability to precisely differentiate closely related species, provide rapid results, and work with various life stages of organisms. Its applications range from species discovery and classification to conservation biology, forensic science, and the assessment of ecosystem health. Overall, DNA barcoding serves as a valuable tool for taxonomists, ecologists, and researchers interested in understanding and documenting the vast array of species present in the natural world.
Etymology of DNA BARCODING
The word "DNA barcoding" is derived from the combination of two terms: "DNA" and "barcoding".
1. DNA: DNA stands for Deoxyribonucleic Acid, which is the molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all living organisms.
2. Barcoding: The term "barcoding" is borrowed from the concept of using barcodes, commonly seen in products in stores, to identify and track them. Barcodes are unique patterns of bars and spaces that represent various information about the product, such as its price or product code. In the context of DNA barcoding, it refers to the process of identifying and categorizing organisms based on a specific region of their DNA.
Therefore, "DNA barcoding" refers to a method of species identification and classification using specific regions of an organism's DNA, similar to the way barcodes identify different products.
