The European Reference Genome Atlas (ERGA) and the European node of the International Barcode of Life (iBOL Europe), two international communities of scientists brought together under the Biodiversity Genomics Europe Project, are joining forces for “Connections,” a series of blog posts that explore the fascinating world of Biodiversity Genomics and the intersection of their communities. In this blog post, we discuss some commonalities between the genomic approaches followed by our two communities: DNA barcoding and reference genome sequencing.
In our first post, we explored the importance of biodiversity genomics. In the second post, we met iBOL Europe and ERGA, the two communities that power the Biodiversity Genomics Europe project (BGE) by studying biodiversity using different but complementary genomic techniques. Today, we will look at how these two communities perform many similar steps to achieve their goals. This includes collecting biological samples, analyzing genomic data, and applying their findings to support biodiversity conservation initiatives.
Field Sampling: Both iBOL Europe and ERGA start with the first step of collecting material in the field. For iBOL Europe, this involves obtaining tissue samples from both museums and the field, where environmental DNA (eDNA) samples from soil and water are also gathered in addition to flying insects from tools like Malaise traps. Alternatively, ERGA typically obtains tissue samples (for example, leaf cuttings, biopsies, or whole organisms) that require immediate freezing, often in liquid nitrogen, to keep the biological material as intact as possible. This extra layer of care ensures the highest-quality DNA available for in-depth genomic analyses.
From the top of the Alps (left) to the lowlands of the Biebrza Marshes (right), finding samples for barcoding and DNA sequencing often feels like an adventure. However, field sampling must always be carried out with an extra layer of care to ensure that specimens are stored in the most appropriate ways to optimise the time and costs associated with field sampling. This is exemplified by the small tank filled with liquid nitrogen shown on the left-hand figure, which is used to transport and preserve the precious samples down the mountain. Photos by Brad Carlson and Szczepan Skibicki.
Sample Processing: Once in the lab, both communities make use of molecular techniques to extract DNA. However, while barcoding involves DNA extractions from both individual specimens and bulk or environmental samples (that contain multiple organisms), reference genome sequencing is solely focussed on high quality DNA extractions from individual specimens. DNA from individual specimens.
Sequencing: After DNA extraction, both initiatives use next-generation sequencing platforms to decode the genetic material. iBOL Europe often relies on targeted DNA sequencing approaches, but also uses short-read ‘skimming’ for museum specimens, to generate DNA barcodes from environmental samples and reference samples. Meanwhile, ERGA leverages several different types of short-read and long-read data to assemble chromosome-level reference genomes that capture complex genomic regions more effectively.
Data analysis: Both iBOL Europe and ERGA handle large amounts of genomic data. Artificial intelligence (AI) methods increasingly help compare unknown DNA snippets against huge digital libraries or refine the final genome assembly. For iBOL Europe, the goal is to generate DNA barcode reference libraries and use these for accurate species identifications to enable presence/absence monitoring at scale. For ERGA, the data analysis aims at unraveling full genomic architectures from reference genomes, offering clues for evolutionary studies and potential “genetic rescue” strategies for threatened species.
Biodiversity conservation impact: ultimately, the information obtained from both DNA barcoding and reference genome assembly informs conservation actions. DNA barcoding data can help pinpoint hotspots of species diversity or track the spread of invasive species. On the other hand, ERGA’s high-quality genomic resources can guide genetic rescue efforts, revealing which populations have enough genetic diversity to adapt to pressing environmental changes. Although iBOL Europe and ERGA focus on different levels of detail, their workflows share many parallels, with high quality references central to both endeavours, underscoring the collaborative spirit of the BGE project.
Following similar steps, from field sampling to sequencing and analysis, these two communities bring diverse genomic data under one roof. Thus, biodiversity is understood faster and deeper, and there is a stronger scientific basis for protecting life on Earth. Stay tuned for our next post, where we continue to explore the synergies between DNA barcoding and reference genomes.
Read the other posts in the series: