DNA barcoding: a way forward to obtain deep insights about the realistic diversity of living organisms

Abstract

DNA barcoding is an innovative tool to rapidly identify and classify organisms based on highly conserved species-specific DNA sequences. This technique has developed in parallel with other genomic-based investigations, which share special emphasis on the acquisition of data pertaining to hotspots regions of DNA (usually short sequence of DNA up to 400-800 bps). These molecular techniques helped answer many queries that remain unanswered by the traditional approaches to accurately identify organisms across the kingdoms of life. Barcoding has narrowed the gap created between diverse range of ecological and traditional studies previously left by the traditional taxonomists. These internal DNA sequence tags, which serve as molecular operational taxonomic units, originate from both nuclear as well as cytoplasmic DNA, making it further convenient to barcode organisms from lower to higher organisms. The most commonly used DNA regions in molecular taxonomic approaches include the internal transcribed spacer regions in nuclear DNA, Cox1 region in mitochondrial DNA, rbcL and mat K gene in chloroplast DNA. Further, many other DNA regions suitable for barcoding have also been identified. It is increasingly evident from a large number of investigations that DNA barcoding has made Linnaean taxonomic system more accessible and convenient to other traditional biologists. Current understanding of the DNA barcoding will further help to understand the basic mechanism and also reveal applications of this approach in different fields. Primarily these approaches offer traditional taxonomists a great opportunity to expand the realistic inventory of the diversity of flora and fauna on planet earth. This review has been written to have better understanding of the mechanism of DNA barcoding, knowledge of DNA regions that can be used as targets, applications and implications of DNA barcoding.

An isolated crested newt population in Dutch coastal dunes: distribution relict or introduction?

“…In the newt cases mentioned above, there is little doubt about how the isolated distribution pocket originated, but what if a species' natural distribution is poorly known and the distance between pocket and main range is relatively small? Here DNA barcoding could help (Hebert et al, 2003;Mir et al, 2021). A natural distribution relict would be expected to be genetically similar to populations from the nearest edge of the main distribution range.…”

Advances in Nematode Identification: A Journey from Fundamentals to Evolutionary Aspects

“…Morphological parameters can also show variations due to different host plants, nutrition, geographical locations, and other environmental factors as is reported in few free-living and plant parasitic nematodes [16]. Therefore, it can become difficult for untrained individuals or researchers to identify and characterize a particular nematode species on morphology parameters alone [17] and thus, an integration of molecular analysis such as DNA sequences can be promising for accurate and proper identification [18].…”

The introduction of three cryptic tree frog species in the Dutch coastal dunes challenges conservation paradigms

“…Determining the species identity of introduced populations is not always straightforward, especially when dealing with cryptic species complexes (Bickford et al, 2007;Pfenninger and Schwenk, 2007), in which case, genetic tools are required. In most instances, DNA barcoding is a cheap and efficient way to obtain the required information (Hebert et al, 2003;Mir et al, 2021). Cryptic species complexes have typically been identified through phylogeographic surveys (Avise, 2000), so matching sequences obtained from introduced populations against published phylogeographic datasets can reveal the species involved (and whether it is an indigenous species or not) as well as its putative geographic origin (which might well be outside of the country concerned).…”