A quarter of a century after its discovery, molecular genetics continues to reveal secrets about biodiversity, pushing forward “the frontier of knowledge.”
Just type “DNA barcoding” into any search engine to realize that this technique has been around for some time. It has been known since 2003, but new uses are constantly being discovered: it seems to be an inexhaustible source of opportunities to capture the invisible. One of the fields where there are still many discoveries to be made is biodiversity. That is why this series dedicated to DNA barcoding as a frontier science starts from this field of research. In particular, from the world of pollinators, demonstrating that behind this label there are many species other than bees and that many have secret links with the world that hosts them, including humans.
TAKEAWAYS
The database boom
The fundamental role of DNA barcoding in the study of biodiversity revolves around the creation of databases containing information on the various species discovered in different areas and eras. “In itself, it is not an innovative technique, but it forms the basis for other techniques that are. As the databases grow, this opportunity will become increasingly powerful and versatile,” explains Jessica Frigerio, a researcher working in the field of molecular genetics at the University of Milan-Bicocca.
The heart of the problem lies in the vastness of the unknown: “There are about 2 million known species in the world, but we still have at least 8 million to discover. There are so many species in the world and, especially at the genetic level, we know only a tiny percentage of them,” continues Frigerio. This situation is particularly evident when exploring marine environments. When analyzing everything in a water sample taken from deep below the surface, what we find in databases is a very small percentage, around 5%. But this also applies to other categories: cataloging is necessary, and we are doing so, including with DNA barcoding.
To bridge this global knowledge gap, the international organization IBOL (International Barcoding of Life) is coordinating ambitious projects. “The goals are very ambitious, we are talking about 2 million DNA barcoding sequences for a project lasting over 5 years,” explains Frigerio, “and the goal at the European level is to collect more and more samples and contribute significantly to expanding this database.”
In Italy, one of the most biodiverse countries in the European Union, the National Biodiversity Future Center (NBFC), with which Frigerio also collaborates, is creating a specific database for Italian flora and fauna: “We are not just collecting DNA barcoding data, but we are also creating a biobank with actual genetic material, which will then be made available to the global scientific community.”
From bees to hazelnuts: practical applications
By narrowing the field to pollinators, we can see how DNA barcoding is not just pure research. This technique has potential for very concrete applications in agriculture and conservation. Paolo Biella, a researcher specializing in pollinating insects at the University of Milan-Bicocca, explains how this technique is fundamental to his work: “Just as I use a microscope to identify insects, I can also use DNA barcoding as a complementary, additional, integrative, or sometimes even the only possible technique.”
Research work often brings many surprises, especially when it involves DNA study. Biella recounts a recent example: “While carrying out some routine monitoring, we identified a protected species among the insects, one that is on the red list and that we did not expect to find. Without DNA barcoding, we would not have noticed it and would not have been able to plan appropriate conservation measures.”
The biggest surprises come when new species are discovered, and Biella has experienced this firsthand. “While studying the genetic differences between certain populations of the same species in central and northern Europe, or at least what we thought was the same species, we noticed that the differences were so great that it could have been a different species. And indeed, it was!” Finding something new in what is already known is a gift of DNA barcoding, and you don’t have to go far to do it.
The future of DNA barcoding technology
There are countless examples, and a passionate researcher like Biella could list them endlessly if he wanted to. His experience is just one of many testimonials demonstrating the advantages of DNA barcoding today and what it could offer in the near future.
“With this technique, it is no longer necessary to crush the entire insect for analysis; traces of DNA are sufficient to obtain information, even if contained in a small excrement or a few body cells,” explains Biella. While the samples already available and analyzable are being analyzed, the use of this technique is being pushed further, with a particular focus on environmental DNA. Frigerio explains what this involves: “Starting from small fragments of DNA dispersed in the air and contained in flowers, it is possible to trace which species visited the air rather than the flower itself. Just rinse the flower and then process it: you no longer need the physical body of the insect.“ Without detracting from the promises made by this technique, in addition to the frontier of knowledge, there is another one that must be overcome: the economic one. Today, the uneven distribution of funds available for scientific research in different countries poses a problem of geographical distribution of knowledge. ”The percentage of biodiversity and money is inversely proportional,“ observes Frigerio. ”In South America, there is much higher biodiversity than in Canada, and they have much less money to analyze it, so the mapping of global biodiversity is quite uneven. DNA barcoding remains the gold standard technique in science for identifying species, but maximizing its potential also requires making it fair and widespread.”
This series dedicated to DNA barcoding stems from the experience gained in the laboratories of the University of Milan Bicocca and the National Biodiversity Future Center thanks to the FRONTIERS program.
