Comparing DNA Regions to Identify Ocean Microalgae Communities

Jim Crocker
21st March, 2024

Comparing DNA Regions to Identify Ocean Microalgae Communities

Image Source: Natural Science News, 2024

Key Findings

  • Study from Victoria University of Wellington shows V9 gene region captures more diversity in marine microalgae
  • V9 results align well with traditional microscopy, making it effective for monitoring marine biodiversity
  • V4 region is useful for detailed study of dinoflagellates, which can cause harmful algal blooms
Understanding the diversity of life in our oceans is crucial for monitoring ecosystem health and predicting the impacts of environmental change. A recent study from Victoria University of Wellington[1] has made significant strides in the field of marine biology by advancing the way scientists study the diversity of tiny ocean-dwelling plants known as eukaryotic microalgae communities (EMCs). These communities are important because they form the base of the aquatic food web and play a key role in carbon cycling. The study focused on two gene regions, the 18S ribosomal DNA V4 and V9, which are commonly used in metabarcodingā€”a technique that allows scientists to identify multiple species from a single environmental sample by analyzing DNA sequences. Metabarcoding has revolutionized biodiversity studies, allowing for the rapid assessment of species compositions in environmental samples. The effectiveness of the V4 and V9 regions for characterizing the diversity of coastal EMCs from tropical and temperate sites was the main question addressed in the study. The researchers binned the DNA sequences they found, known as amplicon sequence variants (ASVs), into high-level taxonomic groups which include various types of microalgae such as dinoflagellates, diatoms, and chlorophytes. By comparing the number of ASVs and the overall diversity captured by each gene region, the study revealed that the V9 region produced a higher number of raw reads and captured more diversity across all groups examined. Moreover, the V9 region's results were more closely aligned with community compositions determined using traditional light microscopy, a method where scientists visually inspect and identify organisms under a microscope. However, the V4 region had its strengths too. It resolved more ASVs to a deeper taxonomic resolution within the dinoflagellates, a group of microalgae often responsible for harmful algal blooms. This indicates that while the V9 region is generally more effective, the V4 region still holds value for specific applications. The findings from this study suggest that while using multiple gene regions is ideal for characterizing EMCs, the V9 region alone can provide a cost-effective and accurate overview of high-level community biodiversity. This is particularly useful for baseline assessments of ecosystem function, as it reflects the relative abundances within different microalgae groups. This study builds upon previous research[2][3][4] that has explored the use of metabarcoding to assess biodiversity in various ecosystems. Earlier studies have demonstrated the importance of selecting appropriate genetic markers for studying different organisms[3] and have compared the effectiveness of various metabarcoding regions and algorithms[4]. The current study extends this knowledge by providing practical guidance on the use of the V9 region for EMCs, which is especially relevant for routine biomonitoring in marine environments. Additionally, the study contributes to a broader understanding of biodiversity and ecosystem functioning in remote and understudied areas such as those near Antarctica[2]. By identifying the most effective genetic markers for metabarcoding, researchers can better monitor these environments and detect changes that may be driven by human activity. In summary, the Victoria University of Wellington's research has provided valuable insights into the study of marine microalgae diversity. By evaluating the V4 and V9 gene regions, the researchers have offered a practical approach for scientists to monitor the health of marine ecosystems efficiently and cost-effectively. This work not only enhances our current methods but also paves the way for future studies to further unravel the complexities of marine life and its response to a changing world.

GeneticsEcologyMarine Biology


Main Study

1) A comparison of two gene regions for assessing community composition of eukaryotic marine microalgae from coastal ecosystems.

Published 18th March, 2024

Related Studies

2) Metabarcoding the Antarctic Peninsula biodiversity using a multi-gene approach.

3) Genetic Markers for Metabarcoding of Freshwater Microalgae: Review.

4) The effect of metabarcoding 18S rRNA region choice on diversity of microeukaryotes including phytoplankton.

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