Menu
Home
People
Places
Arts
History
Plants & Animals
Science
Life & Culture
Technology
Reference.org
Microbial DNA barcoding
open-in-new
<h2 id="history">History</h2> <p> Using <a href="/facts/Metabarcoding/TYVuG9PV">metabarcoding</a> to assess <a href="/facts/Microbial_communities/SAqtmRkW">microbial communities</a> has a long history. Back in 1972, <a href="/facts/Carl_Woese/uzzVL0LR">Carl Woese</a>, <a href="/facts/Mitchell_Sogin/1auoJEAH">Mitchell Sogin</a> and Stephen Sogin first tried to detect several <a href="/facts/Phylogenetics/bw4rsovt">families</a> within <a href="/facts/Bacteria/wC8xSCsU">bacteria</a> using the 5S <a href="/facts/Ribosomal_RNA/zy5FxddY">rRNA</a> gene.<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a> Only a few years later, a new <a href="/facts/Tree_of_life_(biology)/woHaYdLT">tree of life</a> with three <a href="/facts/Domain_(biology)/RpP6V7n6">domains</a> was proposed by again Woese and colleagues, who were the first to use the <a href="/facts/Ribosomal_RNA/zy5FxddY">small subunit of the ribosomal RNA (SSU rRNA)</a> gene to distinguish between bacteria, <a href="/facts/Archaea/Adxh0aHw">archaea</a> and <a href="/facts/Eukaryote/SkwyPLMA">eukaryotes</a>.<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a> Out of this approach, the SSU rRNA gene made its way to be the most frequently used <a href="/facts/Genetic_marker/pRshdIBz">genetic marker</a> for both <a href="/facts/Prokaryote/oYyvaDDH">prokaryotes</a> (16S rRNA) and eukaryotes (<a href="/facts/18S_ribosomal_RNA/wIwGu6Io">18S rRNA</a>). The tedious process of <a href="/facts/Cloning/Vb6SM4c7">cloning</a> those DNA fragments for <a href="/facts/Sequencing/ncpzobwG">sequencing</a> got fastened up by the steady improvement of sequencing technologies. With the development of <a href="/facts/High-throughput_screening/503vkz1b">HTS (High-Throughput-Sequencing)</a> in the early 2000s and the ability to deal with this massive data using modern bioinformatics and cluster algorithms, investigating microbial life got much easier. </p> <h2 id="genetic-markers">Genetic markers</h2> <p>Genetic diversity is varying from species to species. Therefore, it is possible to identify distinct species by the recovery of a short DNA sequence from a standard part of the genome. This short sequence is defined as barcode sequence. Requirements for a specific part of the genome to serve as barcode should be a high variation between two different <a href="/facts/Species/oDg6b96r">species</a>, but not much differences in the gene between two individuals of the same species to make differentiating individual species easier.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a><a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a> For both bacteria and archaea the 16S rRNA/rDNA gene is used. It is a common <a href="/facts/Housekeeping_genes/N9yVF3lR">housekeeping gene</a> in all prokaryotic organisms and therefore is used as a standard barcode to assess prokaryotic diversity. For protists, the corresponding 18S rRNA/rDNA gene is used.<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a> To distinguish different species of fungi, the ITS (<a href="/facts/Internal_transcribed_spacer/s1QsaLEv">Internal Transcribed Spacer</a>) region of the ribosomal <a href="/facts/Cistron/f3Y6cALz">cistron</a> is used.<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a> </p> <h2 id="advantages">Advantages</h2> <p>The existing diversity of the microbial world is not unraveled completely yet, although we know that it is mainly composed by bacteria, fungi and unicellular eukaryotes.<a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a> Taxonomic identification of microbial eukaryotes requires exceedingly skillful expertise and is often difficult due to small sizes of the organisms, fragmented individuals, hidden <a href="/facts/Biodiversity/GruakEzs">diversity</a> and <a href="/facts/Species_complex/u6qEMdRQ">cryptic species</a>.<a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a><a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a> Further, prokaryotes can simply not be taxonomically assigned using traditional methods like <a href="/facts/Microscopy/GpHlElDS">microscopy</a>, because they are too small and <a href="/facts/Morphology_(biology)/Nl3B0myy">morphologically</a> indistinguishable. Therefore, via the use of DNA metabarcoding, it is possible to identify organisms without taxonomic expertise by matching short High Throughput Sequences (HTS)-derived gene fragments to a reference sequence database, e.g. <a href="/facts/National_Center_for_Biotechnology_Information/6Xj5wCbu">NCBI</a>.<a class="footnote-ref" id="fnref:11" href="#fn:11"><sup>11</sup></a> These mentioned qualities make DNA barcoding a cost-effective, reliable and less time-consuming method, compared to the traditional ones, to meet the increasing need for large-scale environmental assessments. </p> <h2 id="applications">Applications</h2> <p>A lot of studies followed the first usage of Woese et al., and are now covering a variety of applications. Not only in biological or ecological research <a href="/facts/DNA_barcoding/gtkyL80c">metabarcoding</a> is used. Also in medicine and human biology bacterial barcodes are used, e.g. to investigate the <a href="/facts/Microbiota/V4ymrawz">microbiome</a> and bacterial colonization of the human gut in normal and obese twins<a class="footnote-ref" id="fnref:12" href="#fn:12"><sup>12</sup></a> or comparison studies of newborn, child and adult gut bacteria composition.<a class="footnote-ref" id="fnref:13" href="#fn:13"><sup>13</sup></a> Additionally, barcoding plays a major role in biomonitoring of e.g. rivers and streams<a class="footnote-ref" id="fnref:14" href="#fn:14"><sup>14</sup></a> and grassland restoration.<a class="footnote-ref" id="fnref:15" href="#fn:15"><sup>15</sup></a> Conservation parasitology, environmental parasitology and paleoparasitology rely on barcoding as a useful tool in disease investigating and management, too.<a class="footnote-ref" id="fnref:16" href="#fn:16"><sup>16</sup></a> </p> <h3>Cyanobacteria</h3> <p><a href="/facts/Cyanobacteria/S8bKxIU9">Cyanobacteria</a> are a group of <a href="/facts/Photosynthesis/TMV7w693">photosynthetic</a> <a href="/facts/Prokaryote/oYyvaDDH">prokaryotes</a>. Similar as in other prokaryotes, <a href="/facts/Taxonomy_(biology)/Qkg8wuyw">taxonomy</a> of cyanobacteria using <a href="/facts/Nucleic_acid_sequence/qAf4kTee">DNA sequences</a> is mostly based on similarity within the <a href="/facts/16S_ribosomal_RNA/XCgSahoy">16S</a> ribosomal gene.<a class="footnote-ref" id="fnref:17" href="#fn:17"><sup>17</sup></a> Thus, the most common barcode used for identification of cyanobacteria is 16S <a href="/facts/Ribosomal_DNA/r0Ah7R7L">rDNA</a> marker. While it is difficult to define <a href="/facts/Species/oDg6b96r">species</a> within prokaryotic organisms, 16S marker can be used for determining individual operational taxonomic units (OTUs). In some cases, these OTUs can also be linked to traditionally defined species and can therefore be considered a reliable representation of the <a href="/facts/Evolution/Hj0qAaBk">evolutionary</a> relationships.<a class="footnote-ref" id="fnref:18" href="#fn:18"><sup>18</sup></a> </p> <p>However, when analyzing a taxonomic structure or <a href="/facts/Biodiversity/GruakEzs">biodiversity</a> of a whole cyanobacterial community (see <a href="/facts/Metabarcoding/TYVuG9PV">DNA metabarcoding</a>), it is more informative to use markers specific for cyanobacteria. Universal 16S bacterial primers have been used successfully to isolate cyanobacterial rDNA from <a href="/facts/Environmental_DNA/GG7dGwyP">environmental samples</a>, but they also recover many bacterial sequences.<a class="footnote-ref" id="fnref:19" href="#fn:19"><sup>19</sup></a><a class="footnote-ref" id="fnref:20" href="#fn:20"><sup>20</sup></a> The use of cyanobacteria-specific<a class="footnote-ref" id="fnref:21" href="#fn:21"><sup>21</sup></a> or phyto-specific 16S markers is commonly used for focusing on cyanobacteria only.<a class="footnote-ref" id="fnref:22" href="#fn:22"><sup>22</sup></a> A few sets of such primers have been tested for barcoding or metabarcoding of environmental samples and gave good results, screening out majority of non-photosynthetic or non-cyanobacterial organisms.<a class="footnote-ref" id="fnref:23" href="#fn:23"><sup>23</sup></a><a class="footnote-ref" id="fnref:24" href="#fn:24"><sup>24</sup></a><a class="footnote-ref" id="fnref:25" href="#fn:25"><sup>25</sup></a><a class="footnote-ref" id="fnref:26" href="#fn:26"><sup>26</sup></a> </p><p>Number of sequenced cyanobacterial genomes available in databases is increasing.<a class="footnote-ref" id="fnref:27" href="#fn:27"><sup>27</sup></a> Besides 16S marker, <a href="/facts/Phylogenetics/bw4rsovt">phylogenetic</a> studies could therefore include also more variable sequences, such as sequences of <a href="/facts/Protein/Jxmagu3E">protein</a>-coding genes (gyrB, rpoC, rpoD,<a class="footnote-ref" id="fnref:28" href="#fn:28"><sup>28</sup></a> rbcL, hetR,<a class="footnote-ref" id="fnref:29" href="#fn:29"><sup>29</sup></a> psbA,<a class="footnote-ref" id="fnref:30" href="#fn:30"><sup>30</sup></a><a class="footnote-ref" id="fnref:31" href="#fn:31"><sup>31</sup></a> rnpB,<a class="footnote-ref" id="fnref:32" href="#fn:32"><sup>32</sup></a> nifH,<a class="footnote-ref" id="fnref:33" href="#fn:33"><sup>33</sup></a> nifD<a class="footnote-ref" id="fnref:34" href="#fn:34"><sup>34</sup></a>), internal transcribed spacer of ribosomal RNA genes (16S-23S rRNA-ITS)<a class="footnote-ref" id="fnref:35" href="#fn:35"><sup>35</sup></a><a class="footnote-ref" id="fnref:36" href="#fn:36"><sup>36</sup></a> or phycocyanin intergenic spacer (PC-IGS).<a class="footnote-ref" id="fnref:37" href="#fn:37"><sup>37</sup></a> However, nifD and nifH can only be used for identification of nitrogen-fixing cyanobacterial strains. </p><p>DNA barcoding of cyanobacteria can be applied in various ecological, evolutionary and taxonomical studies. Some examples include assessment of cyanobacterial diversity and community structure,<a class="footnote-ref" id="fnref:38" href="#fn:38"><sup>38</sup></a> identification of harmful cyanobacteria in ecologically and economically important waterbodies<a class="footnote-ref" id="fnref:39" href="#fn:39"><sup>39</sup></a> and assessment of cyanobacterial <a href="/facts/Symbiosis/MrBArRGa">symbionts</a> in <a href="/facts/Marine_life/TF5MGzFb">marine</a> <a href="/facts/Invertebrate/3CyqCVnN">invertebrates</a>.<a class="footnote-ref" id="fnref:40" href="#fn:40"><sup>40</sup></a> It has a potential to serve as a part of routine <a href="/facts/Environmental_monitoring/ScUSz2ga">monitoring</a> programs for occurrence of cyanobacteria, as well as early detection of potentially <a href="/facts/Cyanotoxin/36QhPPYX">toxic</a> species in waterbodies. This might help us detect harmful species before they start to form <a href="/facts/Cyanotoxin/36QhPPYX">blooms</a> and thus improve our water management strategies. Species identification based on environmental DNA could be particularly useful for cyanobacteria, as traditional identification using microscopy is challenging. Their morphological characteristics which are the basis for species delimitation vary in different growth conditions.<a class="footnote-ref" id="fnref:41" href="#fn:41"><sup>41</sup></a><a class="footnote-ref" id="fnref:42" href="#fn:42"><sup>42</sup></a> Identification under microscope is also time-consuming and therefore relatively costly. Molecular methods can detect much lower concentration of cyanobacterial cells in the sample than traditional identification methods. </p> <h2 id="reference-databases">Reference databases</h2> <p>The reference database is a collection of DNA sequences, which are assigned to either a species or a function. It can be used to link molecular obtained sequences of an organism to pre-existing taxonomy. General databases like the <a href="/facts/National_Center_for_Biotechnology_Information/6Xj5wCbu">NCBI</a> platform include all kind of sequences, either whole genomes or specific marker genes of all organisms. There are also different platforms where only sequences from a distinct group of organisms are stored, e.g. UNITE database<a class="footnote-ref" id="fnref:43" href="#fn:43"><sup>43</sup></a> exclusively for fungi sequences or the PR2 database solely for protist ribosomal sequences.<a class="footnote-ref" id="fnref:44" href="#fn:44"><sup>44</sup></a> Some databases are curated, which allows a taxonomic assignment with higher accuracy than using uncurated databases as a reference. </p> <h2 id="see-also">See also</h2> <ul><li><a href="/facts/Consortium_for_the_Barcode_of_Life/UU1SI2kf">Consortium for the Barcode of Life</a></li> <li><a href="/facts/Algae_DNA_barcoding/XEuFulIB">Algae DNA barcoding</a></li> <li><a href="/facts/DNA_barcoding/gtkyL80c">DNA Barcoding</a></li> <li><a href="/facts/DNA_barcoding_in_diet_assessment/D1XNs6vu">DNA barcoding in diet assessment</a></li> <li><a href="/facts/Fish_DNA_barcoding/NEw9Fhze">Fish DNA barcoding</a></li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>Elbrecht V, Leese F (8 July 2015). "Can DNA-Based Ecosystem Assessments Quantify Species Abundance? Testing Primer Bias and Biomass--Sequence Relationships with an Innovative Metabarcoding Protocol". PLOS ONE. 10 (7): e0130324. Bibcode:2015PLoSO..1030324E. doi:10.1371/journal.pone.0130324. PMC 4496048. PMID 26154168. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4496048" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4496048</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>Sogin SJ, Sogin ML, Woese CR (June 1972). "Phylogenetic measurement in procaryotes by primary structural characterization". Journal of Molecular Evolution. 1 (2): 173–84. Bibcode:1972JMolE...1..173S. doi:10.1007/BF01659163. PMID 24173440. S2CID 3666143. <a href="/wiki/Bibcode_(identifier)" target="_blank">/wiki/Bibcode_(identifier)</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>Woese CR, Kandler O, Wheelis ML (June 1990). "Towards a natural system of organisms: proposal for the domains Archaea, Bacteria, and Eucarya". Proceedings of the National Academy of Sciences of the United States of America. 87 (12): 4576–9. Bibcode:1990PNAS...87.4576W. doi:10.1073/pnas.87.12.4576. PMC 54159. PMID 2112744. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC54159" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC54159</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>Chakraborty C, Doss CG, Patra BC, Bandyopadhyay S (April 2014). "DNA barcoding to map the microbial communities: current advances and future directions". Applied Microbiology and Biotechnology. 98 (8): 3425–36. doi:10.1007/s00253-014-5550-9. PMID 24522727. S2CID 17591196. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>Hajibabaei M, Singer GA, Clare EL, Hebert PD (June 2007). "Design and applicability of DNA arrays and DNA barcodes in biodiversity monitoring". BMC Biology. 5 (1): 24. doi:10.1186/1741-7007-5-24. PMC 1906742. PMID 17567898. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1906742" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1906742</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>Gardham S, Hose GC, Stephenson S, Chariton AA (2014). "DNA Metabarcoding Meets Experimental Ecotoxicology". Big Data in Ecology. Advances in Ecological Research. Vol. 51. pp. 79–104. doi:10.1016/B978-0-08-099970-8.00007-5. ISBN 978-0-08-099970-8. <a href="978-0-08-099970-8" target="_blank">978-0-08-099970-8</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> <li id="fn:7"><p>Creer S, Deiner K, Frey S, Porazinska D, Taberlet P, Thomas WK, Potter C, Bik HM (September 2016). "The ecologist's field guide to sequence-based identification of biodiversity" (PDF). Methods in Ecology and Evolution. 7 (9): 1008–1018. doi:10.1111/2041-210X.12574. <a href="https://pure.aber.ac.uk/ws/files/27228629/Creer_et_al_2016_Methods_in_Ecology_and_Evolution.pdf" target="_blank">https://pure.aber.ac.uk/ws/files/27228629/Creer_et_al_2016_Methods_in_Ecology_and_Evolution.pdf</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li> <li id="fn:8"><p>Chakraborty C, Doss CG, Patra BC, Bandyopadhyay S (April 2014). "DNA barcoding to map the microbial communities: current advances and future directions". Applied Microbiology and Biotechnology. 98 (8): 3425–36. doi:10.1007/s00253-014-5550-9. PMID 24522727. S2CID 17591196. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li> <li id="fn:9"><p>Bickford D, Lohman DJ, Sodhi NS, Ng PK, Meier R, Winker K, Ingram KK, Das I (March 2007). "Cryptic species as a window on diversity and conservation" (PDF). Trends in Ecology & Evolution. 22 (3): 148–55. doi:10.1016/j.tree.2006.11.004. PMID 17129636. <a href="http://ir.unimas.my/3324/1/Cryptic%20species%20as%20a%20window%20on%20diversity%20and%20conservation.pdf" target="_blank">http://ir.unimas.my/3324/1/Cryptic%20species%20as%20a%20window%20on%20diversity%20and%20conservation.pdf</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li> <li id="fn:10"><p>Sáez AG, Lozano E (January 2005). "Body doubles". Nature. 433 (7022): 111. Bibcode:2005Natur.433..111S. doi:10.1038/433111a. PMID 15650721. S2CID 4413395. <a href="https://doi.org/10.1038%2F433111a" target="_blank">https://doi.org/10.1038%2F433111a</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></p></li> <li id="fn:11"><p>Keeley N, Wood SA, Pochon X (February 2018). "Development and preliminary validation of a multi-trophic metabarcoding biotic index for monitoring benthic organic enrichment". Ecological Indicators. 85: 1044–1057. doi:10.1016/j.ecolind.2017.11.014. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></p></li> <li id="fn:12"><p>Turnbaugh PJ, Hamady M, Yatsunenko T, Cantarel BL, Duncan A, Ley RE, Sogin ML, Jones WJ, Roe BA, Affourtit JP, Egholm M, Henrissat B, Heath AC, Knight R, Gordon JI (January 2009). "A core gut microbiome in obese and lean twins". Nature. 457 (7228): 480–4. Bibcode:2009Natur.457..480T. doi:10.1038/nature07540. PMC 2677729. PMID 19043404. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2677729" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2677729</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></p></li> <li id="fn:13"><p>Yatsunenko T, Rey FE, Manary MJ, Trehan I, Dominguez-Bello MG, Contreras M, Magris M, Hidalgo G, Baldassano RN, Anokhin AP, Heath AC, Warner B, Reeder J, Kuczynski J, Caporaso JG, Lozupone CA, Lauber C, Clemente JC, Knights D, Knight R, Gordon JI (May 2012). "Human gut microbiome viewed across age and geography". Nature. 486 (7402): 222–7. Bibcode:2012Natur.486..222Y. doi:10.1038/nature11053. PMC 3376388. PMID 22699611. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3376388" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3376388</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></p></li> <li id="fn:14"><p>Vasselon V, Rimet F, Tapolczai K, Bouchez A (November 2017). "Assessing ecological status with diatoms DNA metabarcoding: Scaling-up on a WFD monitoring network (Mayotte island, France)". Ecological Indicators. 82: 1–12. doi:10.1016/j.ecolind.2017.06.024. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:14" class="footnote-back-ref">↩</a></p></li> <li id="fn:15"><p>Guo Y, Hou L, Zhang Z, Zhang J, Cheng J, Wei G, Lin Y (12 March 2019). "Soil Microbial Diversity During 30 Years of Grassland Restoration on the Loess Plateau: Tight Linkages With Plant Diversity". Land Degradation & Development. doi:10.1002/ldr.3300. S2CID 133936992. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:15" class="footnote-back-ref">↩</a></p></li> <li id="fn:16"><p>Morand S (April 2018). "Advances and challenges in barcoding of microbes, parasites, and their vectors and reservoirs". Parasitology. 145 (5): 537–542. doi:10.1017/S0031182018000884. PMID 29900810. <a href="https://doi.org/10.1017%2FS0031182018000884" target="_blank">https://doi.org/10.1017%2FS0031182018000884</a> <a href="#fnref:16" class="footnote-back-ref">↩</a></p></li> <li id="fn:17"><p>Rosselló-Mora R (September 2005). "Updating prokaryotic taxonomy". Journal of Bacteriology. 187 (18): 6255–7. doi:10.1128/JB.187.18.6255-6257.2005. PMC 1236658. PMID 16159756. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1236658" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1236658</a> <a href="#fnref:17" class="footnote-back-ref">↩</a></p></li> <li id="fn:18"><p>Eckert EM, Fontaneto D, Coci M, Callieri C (December 2014). "Does a barcoding gap exist in prokaryotes? Evidences from species delimitation in cyanobacteria". Life. 5 (1): 50–64. doi:10.3390/life5010050. PMC 4390840. PMID 25561355. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4390840" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4390840</a> <a href="#fnref:18" class="footnote-back-ref">↩</a></p></li> <li id="fn:19"><p>Rappé MS, Suzuki MT, Vergin KL, Giovannoni SJ (January 1998). "Phylogenetic diversity of ultraplankton plastid small-subunit rRNA genes recovered in environmental nucleic acid samples from the Pacific and Atlantic coasts of the United States". Applied and Environmental Microbiology. 64 (1): 294–303. Bibcode:1998ApEnM..64..294R. doi:10.1128/AEM.64.1.294-303.1998. PMC 124708. PMID 9435081. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC124708" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC124708</a> <a href="#fnref:19" class="footnote-back-ref">↩</a></p></li> <li id="fn:20"><p>Van der Gucht K, Vandekerckhove T, Vloemans N, Cousin S, Muylaert K, Sabbe K, Gillis M, Declerk S, De Meester L, Vyverman W (July 2005). "Characterization of bacterial communities in four freshwater lakes differing in nutrient load and food web structure". FEMS Microbiology Ecology. 53 (2): 205–20. doi:10.1016/j.femsec.2004.12.006. PMID 16329941. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:20" class="footnote-back-ref">↩</a></p></li> <li id="fn:21"><p>Nübel U, Garcia-Pichel F, Muyzer G (August 1997). "PCR primers to amplify 16S rRNA genes from cyanobacteria". Applied and Environmental Microbiology. 63 (8): 3327–32. Bibcode:1997ApEnM..63.3327N. doi:10.1128/AEM.63.8.3327-3332.1997. PMC 168636. PMID 9251225. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC168636" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC168636</a> <a href="#fnref:21" class="footnote-back-ref">↩</a></p></li> <li id="fn:22"><p>Stiller JW, McClanahan AN (March 2005). "Phyto-specific 16S rDNA PCR primers for recovering algal and plant sequences from mixed samples". Molecular Ecology Notes. 5 (1): 1–3. doi:10.1111/j.1471-8286.2004.00805.x. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:22" class="footnote-back-ref">↩</a></p></li> <li id="fn:23"><p>Betournay S, Marsh AC, Donello N, Stiller JW (June 2007). "Selective recovery of microalgae from diverse habitats using 'phyto-specific' 16S rDNA primers". Journal of Phycology. 43 (3): 609–613. doi:10.1111/j.1529-8817.2007.00350.x. S2CID 84399666. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:23" class="footnote-back-ref">↩</a></p></li> <li id="fn:24"><p>Stiller JW, McClanahan AN (March 2005). "Phyto-specific 16S rDNA PCR primers for recovering algal and plant sequences from mixed samples". Molecular Ecology Notes. 5 (1): 1–3. doi:10.1111/j.1471-8286.2004.00805.x. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:24" class="footnote-back-ref">↩</a></p></li> <li id="fn:25"><p>Boutte C, Grubisic S, Balthasart P, Wilmotte A (June 2006). "Testing of primers for the study of cyanobacterial molecular diversity by DGGE". Journal of Microbiological Methods. 65 (3): 542–50. doi:10.1016/j.mimet.2005.09.017. hdl:2268/19902. PMID 16290299. <a href="http://orbi.ulg.ac.be/handle/2268/19902" target="_blank">http://orbi.ulg.ac.be/handle/2268/19902</a> <a href="#fnref:25" class="footnote-back-ref">↩</a></p></li> <li id="fn:26"><p>López-Legentil S, Song B, Bosch M, Pawlik JR, Turon X (22 August 2011). "Cyanobacterial diversity and a new acaryochloris-like symbiont from Bahamian sea-squirts". PLOS ONE. 6 (8): e23938. Bibcode:2011PLoSO...623938L. doi:10.1371/journal.pone.0023938. PMC 3161822. PMID 21915246. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3161822" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3161822</a> <a href="#fnref:26" class="footnote-back-ref">↩</a></p></li> <li id="fn:27"><p>Juteršek M, Klemenčič M, Dolinar M (December 2017). "Discrimination Between Synechocystis Members (Cyanobacteria) Based on Heterogeneity of Their 16S rRNA and ITS Regions". Acta Chimica Slovenica. 64 (4): 804–817. doi:10.17344/acsi.2017.3262. PMID 29318299. <a href="https://doi.org/10.17344%2Facsi.2017.3262" target="_blank">https://doi.org/10.17344%2Facsi.2017.3262</a> <a href="#fnref:27" class="footnote-back-ref">↩</a></p></li> <li id="fn:28"><p>Seo PS, Yokota A (June 2003). "The phylogenetic relationships of cyanobacteria inferred from 16S rRNA, gyrB, rpoC1 and rpoD1 gene sequences". The Journal of General and Applied Microbiology. 49 (3): 191–203. doi:10.2323/jgam.49.191. PMID 12949700. <a href="https://doi.org/10.2323%2Fjgam.49.191" target="_blank">https://doi.org/10.2323%2Fjgam.49.191</a> <a href="#fnref:28" class="footnote-back-ref">↩</a></p></li> <li id="fn:29"><p>Tomitani A, Knoll AH, Cavanaugh CM, Ohno T (April 2006). "The evolutionary diversification of cyanobacteria: molecular-phylogenetic and paleontological perspectives". Proceedings of the National Academy of Sciences of the United States of America. 103 (14): 5442–7. Bibcode:2006PNAS..103.5442T. doi:10.1073/pnas.0600999103. PMC 1459374. PMID 16569695. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1459374" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1459374</a> <a href="#fnref:29" class="footnote-back-ref">↩</a></p></li> <li id="fn:30"><p>Hess WR, Weihe A, Loiseaux-de Goër S, Partensky F, Vaulot D (March 1995). "Characterization of the single psbA gene of Prochlorococcus marinus CCMP 1375 (Prochlorophyta)". Plant Molecular Biology. 27 (6): 1189–96. doi:10.1007/BF00020892. PMID 7766900. S2CID 26973191. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:30" class="footnote-back-ref">↩</a></p></li> <li id="fn:31"><p>Morden CW, Golden SS (January 1989). "psbA genes indicate common ancestry of prochlorophytes and chloroplasts". Nature. 337 (6205): 382–5. Bibcode:1989Natur.337..382M. doi:10.1038/337382a0. PMID 2643058. S2CID 4275907. <a href="/wiki/Bibcode_(identifier)" target="_blank">/wiki/Bibcode_(identifier)</a> <a href="#fnref:31" class="footnote-back-ref">↩</a></p></li> <li id="fn:32"><p>Vioque A (September 1997). "The RNase P RNA from cyanobacteria: short tandemly repeated repetitive (STRR) sequences are present within the RNase P RNA gene in heterocyst-forming cyanobacteria". Nucleic Acids Research. 25 (17): 3471–7. doi:10.1093/nar/25.17.3471. PMC 146911. PMID 9254706. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC146911" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC146911</a> <a href="#fnref:32" class="footnote-back-ref">↩</a></p></li> <li id="fn:33"><p>Zehr JP, Mellon MT, Hiorns WD (April 1997). "Phylogeny of cyanobacterial nifH genes: evolutionary implications and potential applications to natural assemblages". Microbiology. 143 ( Pt 4) (4): 1443–50. doi:10.1099/00221287-143-4-1443. PMID 9141707. <a href="https://doi.org/10.1099%2F00221287-143-4-1443" target="_blank">https://doi.org/10.1099%2F00221287-143-4-1443</a> <a href="#fnref:33" class="footnote-back-ref">↩</a></p></li> <li id="fn:34"><p>Henson BJ, Hesselbrock SM, Watson LE, Barnum SR (March 2004). "Molecular phylogeny of the heterocystous cyanobacteria (subsections IV and V) based on nifD". International Journal of Systematic and Evolutionary Microbiology. 54 (Pt 2): 493–7. doi:10.1099/ijs.0.02821-0. PMID 15023966. <a href="https://doi.org/10.1099%2Fijs.0.02821-0" target="_blank">https://doi.org/10.1099%2Fijs.0.02821-0</a> <a href="#fnref:34" class="footnote-back-ref">↩</a></p></li> <li id="fn:35"><p>Piccin-Santos V, Brandão MM, Bittencourt-Oliveira M (August 2014). Gabrielson P (ed.). "Phylogenetic study of Geitlerinema and Microcystis (Cyanobacteria) using PC-IGS and 16S-23S ITS as markers: investigation of horizontal gene transfer". Journal of Phycology. 50 (4): 736–43. doi:10.1111/jpy.12204. PMID 26988457. S2CID 37954121. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:35" class="footnote-back-ref">↩</a></p></li> <li id="fn:36"><p>Juteršek M, Klemenčič M, Dolinar M (December 2017). "Discrimination Between Synechocystis Members (Cyanobacteria) Based on Heterogeneity of Their 16S rRNA and ITS Regions". Acta Chimica Slovenica. 64 (4): 804–817. doi:10.17344/acsi.2017.3262. PMID 29318299. <a href="https://doi.org/10.17344%2Facsi.2017.3262" target="_blank">https://doi.org/10.17344%2Facsi.2017.3262</a> <a href="#fnref:36" class="footnote-back-ref">↩</a></p></li> <li id="fn:37"><p>Piccin-Santos V, Brandão MM, Bittencourt-Oliveira M (August 2014). Gabrielson P (ed.). "Phylogenetic study of Geitlerinema and Microcystis (Cyanobacteria) using PC-IGS and 16S-23S ITS as markers: investigation of horizontal gene transfer". Journal of Phycology. 50 (4): 736–43. doi:10.1111/jpy.12204. PMID 26988457. S2CID 37954121. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:37" class="footnote-back-ref">↩</a></p></li> <li id="fn:38"><p>Dadheech PK, Glöckner G, Casper P, Kotut K, Mazzoni CJ, Mbedi S, Krienitz L (August 2013). "Cyanobacterial diversity in the hot spring, pelagic and benthic habitats of a tropical soda lake". FEMS Microbiology Ecology. 85 (2): 389–401. doi:10.1111/1574-6941.12128. PMID 23586739. <a href="https://doi.org/10.1111%2F1574-6941.12128" target="_blank">https://doi.org/10.1111%2F1574-6941.12128</a> <a href="#fnref:38" class="footnote-back-ref">↩</a></p></li> <li id="fn:39"><p>Kurobe T, Baxa DV, Mioni CE, Kudela RM, Smythe TR, Waller S, Chapman AD, Teh SJ (2013). "Identification of harmful cyanobacteria in the Sacramento-San Joaquin Delta and Clear Lake, California by DNA barcoding". SpringerPlus. 2 (1): 491. doi:10.1186/2193-1801-2-491. PMC 3797325. PMID 24133644. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3797325" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3797325</a> <a href="#fnref:39" class="footnote-back-ref">↩</a></p></li> <li id="fn:40"><p>López-Legentil S, Song B, Bosch M, Pawlik JR, Turon X (22 August 2011). "Cyanobacterial diversity and a new acaryochloris-like symbiont from Bahamian sea-squirts". PLOS ONE. 6 (8): e23938. Bibcode:2011PLoSO...623938L. doi:10.1371/journal.pone.0023938. PMC 3161822. PMID 21915246. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3161822" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3161822</a> <a href="#fnref:40" class="footnote-back-ref">↩</a></p></li> <li id="fn:41"><p>Nübel U, Garcia-Pichel F, Muyzer G (August 1997). "PCR primers to amplify 16S rRNA genes from cyanobacteria". Applied and Environmental Microbiology. 63 (8): 3327–32. Bibcode:1997ApEnM..63.3327N. doi:10.1128/AEM.63.8.3327-3332.1997. PMC 168636. PMID 9251225. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC168636" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC168636</a> <a href="#fnref:41" class="footnote-back-ref">↩</a></p></li> <li id="fn:42"><p>Gugger M, Lyra C, Henriksen P, Couté A, Humbert JF, Sivonen K (September 2002). "Phylogenetic comparison of the cyanobacterial genera Anabaena and Aphanizomenon". International Journal of Systematic and Evolutionary Microbiology. 52 (Pt 5): 1867–80. doi:10.1099/00207713-52-5-1867. PMID 12361299. <a href="https://doi.org/10.1099%2F00207713-52-5-1867" target="_blank">https://doi.org/10.1099%2F00207713-52-5-1867</a> <a href="#fnref:42" class="footnote-back-ref">↩</a></p></li> <li id="fn:43"><p>"UNITE". unite.ut.ee. Retrieved 2019-03-28. <a href="https://unite.ut.ee/" target="_blank">https://unite.ut.ee/</a> <a href="#fnref:43" class="footnote-back-ref">↩</a></p></li> <li id="fn:44"><p>Guillou L, Bachar D, Audic S, Bass D, Berney C, Bittner L, et al. (January 2013). "The Protist Ribosomal Reference database (PR2): a catalog of unicellular eukaryote small sub-unit rRNA sequences with curated taxonomy". Nucleic Acids Research. 41 (Database issue): D597–604. doi:10.1093/nar/gks1160. PMC 3531120. PMID 23193267. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3531120" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3531120</a> <a href="#fnref:44" class="footnote-back-ref">↩</a></p></li> </ol>