New
Paper On Deep-Sea Metabarcoding
By
Xavier Turon
DNA
Metabarcoding of Deep-Sea Sediment Communities Using COI: Community
Assessment, Spatio-Temporal Patterns and Comparison with 18S rDNA
By
Atienza S, Guardiola M, Præbel K, Antich A, Turon X, Wangensteen OS
Diversity
2020, 12:123 DOI 10.3390/d12040123
Our
paper on COI metabarcoding of sediment communities in deep-sea
canyons in NW Mediterranean has been published in the special issue
Molecular Biodiversity Assessment in the Deep Sea of the Diversity
Journal.
Metabarcoding
highlights our current deep ignorance on deep-sea communities. We
know just 2,805 morphological species from deep Mediterranean. But we
detected > 15,000 MOTUs in our very local study! COI Leray-XT
recovers the same ecological patterns than 18S, but with enhanced
potential for development of novel taxonomy-free ecological
bioindicators.
Here
is the abstract:
Among
the complex ecosystems and habitats that form the deep sea, submarine
canyons and open slope systems are regarded as potential hotspots of
biodiversity. We assessed the spatial and temporal patterns of
biodiversity in sediment communities of a NW Mediterranean Canyon and
its adjacent open slope (Blanes Canyon) with DNA metabarcoding. We
sampled three layers of sediment and four different depths (900–1750
m) at two seasons, and used a fragment of the mitochondrial gene
cytochrome c oxidase subunit I (COI) as a metabarcoding marker. The
final dataset contained a total of 15,318 molecular operational
taxonomic units (MOTUs). Metazoa, Stramenopiles and Archaeplastida
were the dominant taxa and, within metazoans, Arthropoda, Nematoda
and Cnidaria were the most diverse. There was a trend towards
decreasing MOTU richness and diversity in the first few cm (1 to 5)
of the sediment, with only 26.3% of the MOTUs shared across sediment
layers. Our results show the presence of heterogeneous communities in
the studied area, which was significantly different between zones,
depths and seasons. We compared our results with the ones presented
in a previous study, obtained using the v7 region of the 18S rRNA
gene in the same samples. There were remarkable differences in the
total number of MOTUs and in the most diverse taxa. COI recovered a
higher number of MOTUs, but more remained unassigned taxonomically.
However, the broad spatio-temporal patterns elucidated from both
datasets coincided, with both markers retrieving the same ecological
information. Our results showed that COI can be used to accurately
characterize the studied communities and constitute a high-resolution
method to detect ecological shifts. We also highlight that COI
reference databases for deep-sea organisms have important gaps, and
their completeness is essential in order to successfully apply
metabarcoding techniques.
Keywords:
DNA metabarcoding; COI; 18S rRNA gene; deep-sea; submarine canyons;
meiofauna
With this paper PopCOmics contributes to
further the development of genetic tools applied to α-
and β-diversity
studies in marine communities… more to come soon!