Tag Archives: DNA-barcoding

Student visit – Ana González

MSc student Ana González visited the collections last month as part of project NorHydro, where she spent some weeks in the lab working with her samples. Here is an account of her experience:

The challenge of identifying benthic hydrozoans
Hydrozoa is a fascinating but poorly understood group of invertebrates, in part because their identification is not always an easy task. I have been studying benthic hydrozoan communities for over a year now, in particular those living in the shallow waters of Mallorca (Spain), and I have realized that the diversity of forms and structures in the group is higher than I had imagined at the beginning of my studies, and their identification is more difficult than I expected. The assemblages of hydrozoans in the Mediterranean are of course very different from the ones that occur in Norway, but something that both communities have in common is that morphological identification of the animals (i.e. telling which species is present based only on the characteristics we can observe) is challenging, which is why one of the aims of my visit to the University Museum of Bergen last December was to learn a different technique (DNA barcoding) that can help me improve the identification of my samples in cases when the morphology of the specimens is not good enough.

Some of the morphological characters that are used to identify benthic hydrozoans. On the left side a member of Campanulariidae, with a stolonal colony, and on the right side Monotheca obliqua with an erect colony.

DNA barcoding consists in finding a short DNA sequence (the barcode) that is similar for all members of one species but different from all other species. It is a relatively recent tool that –among other things– has helped the scientific community identify specimens that for one reason or the other cannot be identified based on how they look. In some groups, such as many colonial invertebrates, this technique has become a key asset because the colonies are often too young or not reproductive, or the important characters for identifications may be found only in one stage of the life cycle and not in others. For this visit I had the chance to bring all my samples from Mallorca to Bergen and I set to extracting the DNA of selected specimens, amplifying two different barcode genes (COI and 16S), and obtaining clean sequences for them. I discovered that, when it comes to DNA barcoding, every step of the process is important, and being patient and careful is essential.

Me at the DNA lab, running the electrophoresis for my samples.

Getting good results in the DNA lab depends on several factors like not forgetting any step and avoiding contamination as far as possible, but the work does not end there: once you have your sequences they have to be cleaned, quality-checked, and finally compared with others. This means that having a complete and trustworthy database of DNA barcodes is necessary, especially if you want to use the sequence to help you corroborate the identification of a specimen. When done right and with a good database, the DNA barcodes can be useful to detect differences between hydrozoan assemblages growing in different parts of the world or between different substrates and levels of anthropogenic impact, which is what I am doing in my MSc project.

Left: Clytia sp growing on the marine plant Posidonia oceanica. Center: A polyp of Halecium sp, one of the most difficult genera of Hydrozoa to identify based only in morphology, especially when the colony is not reproductive. Right: Eudendrium sp., found in harbours in Mallorca in high abundances.

The analysis of DNA sequences is a powerful tool to compare specimens of distinct populations and in some cases animals that apparently belong to the same species turn out to be completely different (e.g. cryptic species). This is not uncommon for benthic hydrozoans, which have high morphological diversity but also high levels of plasticity, resulting in colonies from different species sometimes being very similar to each other when they grow in similar substrates. As useful as DNA analyses are, however, it is also important to consider their limitations. For example, while the abundance of each species in a given community is important to describe the ecological status of a habitat, estimating abundance is still not always possible from sequence reads in DNA analyses.

Many cryptic species have been discovered in Aglaopheniidae thanks to the combination of DNA barcoding and morphological analysis

The use of DNA barcodes in my work is not limited to my current project, as I hope my identifications and sequences will help a little bit to improve the databases for future studies of hydrozoan communities in the Mediterranean Sea, and maybe even allow other researchers to compare their samples with the species found on other parts of the world. I think that looking closely at each specimen is the best way to truly know variation, so both morphology observations and DNA analyses should be combined to obtain good estimates of the diversity of a taxon in any locality. For example, whenever the DNA analyses reveal differences in two clades that were thought to be the same species, it is time to search for new taxonomic characters that we might have missed before, and for that reason it is also important to have a good knowledge of the morphology of each species. Both morphological and DNA-based identifications have limitations and advantages so, if you have the opportunity to use both, why choose only one?

Ana

The 8th International Barcode of Life (IBOL) Conference

Logo by Åshild Stolsmo Viken, Norwegian Biodiversity Information Centre

For a week in June, a significant portion of the world’s barcoding community descended on the fair city of Trondheim. 460 participants from 61 countries met up to share their work, exchange ideas, and meet old and new fellow barcoders.

IBOL2019 delegates, photo by Åge Hojem CC-BY-SA-4.0

The University Museum of Bergen was well represented, with 10 scientific contributions being presented.

All the abstracts can be found in this special edition of the journal Genome.

Contributions people from UMB was involved with include:
DNA barcoding reveals cryptic diversity and genetic connectivity in the deep-sea annelids across the Greenland–Scotland Ridge (N. Budaeva et al.)

DNA barcoding assessment of species diversity in marine bristle worms (Annelida), integrating barcoding with traditional morphology-based taxonomy (T. Bakken et al.)

Five years as national research infrastructure: status of the Norwegian Barcode of Life Network (NorBOL) (T. Ekrem et al.)

Molecular study of Chaetozone Malmgren (Annelida, Polychaeta) reveals hidden diversity of a common benthic polychaete (M. Grosse et al.)

DNA barcodes of Nordic Echinodermata (K. Kongshavn et al.)

Ctenophores — native aliens in Norwegian waters (S. Majaneva et al.)

DNA barcoding of Norwegian forest Oribatida — preliminary results reveal several taxonomic problems (A. Seniczak and B. Jordal)

A barcode gap analysis for aquatic biomonitoring in Europe (H. Weigand et al.)

DNA barcoding marine fauna with NorBOL — current status (E. Willassen et al.)

It was a highly enjoyable conference to participate in, both as part of the support structure (“Team Orange”), and as presenter and/or audience.

A subset of “Team Orange”, who contributed to the smooth running of the event (photo: T. Ekrem)

The NorBOL barcode managers together with Paul Hebert, a Canada Research Chair and Director of the Centre for Biodiversity Genomics at the University of Guelph – and one of the masterminds behind IBOL.

The conference venue did a excellent job keeping us energized and happy with a steady supply of wonderful food and caffeinated beverages – and we were treated to a lovely organ concert in the Nidaros cathedral and a delicious dinner reception at  the Archbishop’s Palace.

Oh, my.

The introduction of BIOSCAN, “the newest phase of a 15-year research program that will transform our understanding of, and integration with global biodiversity” was greeted with enthusiasm – you can read more about this ambitious venture on the IBOL web pages.

It was a excellent conference, and we look  forward to continuing our work on building a validated barcode reference library for species found in Norway through the numerous Norwegian Taxonomy Initiative projects (Artsprosjekt) we have running here at UMB.

-Katrine

Door #7: New shipment of tissue samples for barcoding

In the upper right corner is a “plate”: the microplates with 96 wells where we deposit small tissue samples that are to be processed at the CCDB lab in Canada for NorBOL

On the third day of Christmas,
we sent eleven microplates away:
one plate cnidarians (A)
two with worms a-wriggle (B)
two plates of insects (C)
three plates crustaceans (D)
two (and a half) plates of mites (E)
and a half-plate assorted a-arthropods (F)!

Ahem. Yes.

As Endre explained in the fifth post of the calendar, collecting, identifying, documenting and keeping specimens used for DNA barcoding is an important part of what we do here at the invertebrate collections. Our mission in the NORBOL consortium is to produce DNA-barcodes, particularly for marine fauna in Norwegian waters and to make these barcodes available with open access to records and metadata in the BOLD database. These samples contribute to the building of a validated reference library of the genetic barcodes of the species found in Norway. You can search for different taxonomic groups here to see if they have been barcoded from Norwegian territory: Search NorBOL

The process is fairly straight forward (at least on paper!): Animals are collected and identified. Those species relevant for barcoding are selected, and a specimen (=1 animal) is chosen to be barcoded. We take a small tissue sample from the specimen, and keep the rest of the animal as the barcode voucher; if the need should arise to check if it really is what we initially thought, it is crucial to be able to go back and check the animal again. The tissue samples are collected in wells on a plate like the one pictured above, and the information about the animals – where they were collected, who collected them, what species they are, who identified them and so on is uploaded to BOLD together with images of the animals.

Representatives for the tissue sample plates that we just shipped off. Thank you Steffen, Anna and Per for contributing the terrestrial animals and images! Photos: L. Martell, A. Seniczak, S. Roth, K. Kongshavn. Illustration: K. Kongshavn

On Monday we shipped a new batch of plates – as (attempted) illustrated in song above.

Included is material from several of the Norwegian Taxonomy Initiative projects (artsprosjekt) that are happening at the University Museum of Bergen. We are coordinating the efforts on marine life, but are of course also facilitating the NorBOL barcoding of other organisms that take place at the UMB.  There are animals from NorAmph (Norwegian Amphipoda), Hydrozoan pelagic diversity in Norway (HYPNO), Orbatid mites, and the insects found associated with nutrient rich marshes in Hedmark in this shipment.

We have also prepared several plates of Crustaceans collected and identified by the Norwegian marine mapping programme Mareano – one of the great contributors of material to the collections.

Now we wait for the lab to process them, and for the genetic sequences to be uploaded to BOLD – fingers crossed for many interesting results!

-Katrine

Bryozoan barcoding

Haeckel Bryozoa.jpg
By Ernst Haeckel – Kunstformen der Natur (1904), plate 23: Bryozoa (see here, here and here), Public Domain, Link You can also find the whole, gorgeous book by Haeckel here, courtesy of the Biodiversity Heritage Library

I have spent the past week and a half getting acquainted with a rather odd – yet beautiful – group of animals, the Bryozoa, moss animals. These colony-forming, mostly marine, animals are small as individuals, but the colonies can grow quite large. Globally there are around 5000 extant species recorded, with a further 15 000 species in the fossil record. We have colleagues in Oslo who work on both the fossil and the current fauna to better understand micro- and macroevolution, you can read more about that here (og her, på norsk).

Sampling site of barcoded Bryozoans in the BOLD database

Sampling site of barcoded Bryozoans in the BOLD database

This is the first attempt at barcoding bryozoans through NorBOL, and it shows (map above); hopefully we will get more dots on the map for our region soon!

This may not be an easy group to get genetic barcodes from, though – I’ve been in communication with several of the (wonderfully helpful!) experts in the field, and the consensus seems to be that getting a barcode (from the region defined as THE barcode, the 5’ end of COI) will be difficult, and that we may anticipate “..a colourful array of contaminants, as well as nuclear mitochondrial pseudogenes”. Yay. Well, we won’t know until we try!

Together with colleagues from the Natural History Collections in Gothenburg we have assembled a plate of tissue samples from Swedish and Norwegian bryozoan that I will send to the CCDB facilities for sequencing next week. We have an impressive 58 different species (1-3 specimens of each) included on the plate, as well as a few specimens that are (not yet) identified to species.

n344_w1150

Bicellariella ciliata for barcoding

Bicellariella ciliata for barcoding

The colonies can be branching, encrusting, lacelike, lumpy…and at times pretty close to invisible! I’ve had to spend some time looking for good illustrations to know what to sample from… there are often multiple species in a jar, as well as other animals – hopefully I managed.

The specimens on the plate

The specimens on the plate

We’re treating this as a trial plate: is it possible to barcode museum material of bryozoans through the general pipeline, or will we need to get creative?

I’ll make a new post once the verdict is in – let’s hope for surprisingly high success rates!


Some further reading:

Lee et al 2011: DNA Barcode Examination of Bryozoa (Class: Gymnolaemata) in Korean SeawaterKorean J. Syst. Zool. Vol. 27, No. 2: 159-163, July 2011 ISSN 2233-7687
DOI 10.5635/KJSZ.2011.27.2.159

Wikipedia has a nice post on Bryozoa

 

High(er) species diversity of Glyceriformia

goniadidae figHappy WormWednesday*!

One of our contributions at the International Polychaete Conference in Cardiff was a poster that dealt with how a combination of careful morphological examinations using the available literature and DNA barcoding of polychaetes in the families Glyceridae and Goniadidae from the West coast of Africa is indicating a much higher diversity than we can assign names to at the moment.

Head on over to our MIWA (Marine Invertebrates of Western Africa) blog to see the poster and learn more!

*that is an actual hashtag on Twitter – check it out!

Publicity in Barcode Bulletin

Barcode Bulletin is a newsletter from International Barcode of Life (IBOL).  Barcode Bulletin Vol. 4, No. 2 – December 2013 has recently published two stories about activites we are involved in. One nice piece of news is that the  Norwegian Biodiversity Information Center and the Research Council of Norway has decided to fund the NorBol consortium. The other news are about our summer 2013 workshop in the MIWA-project which was co-funded via IPBES.

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