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International Barcode of Life: find more information on barcoding here.

DNA Barcoding

DNA is being extracted for these projects:

  • KwaZulu-Natal project

  • Tshwane conservation project (see Conservation Biology page)

  • Invasive mycorrhizal fungi of the Cape Town and Stellenbosch region

You can find sheets to catalog your finds and samples below:

 

To learn more about what DNA and barcoding is read the insert below.

Contact me at themycologyblog@gmail.com to arrange pickup of your samples.

Recently a great deal of publicity has been given in South Africa to the process of DNA barcoding.  DNA (deoxynucleotide acid) is a molecule occurring in all organisms, and the sequence of four types (called basepairs) stringed together, give the information of how an organism works.  It is also used to determine what an organism is, because parts of the DNA sequence differ between different species. 

   DNA sequencing is when the base pair sequences of species are generated.  The sequence can be compared to those of other species to determine how related or similar they are, or how they differ.  A DNA barcode is part of the DNA sequence that has a unique sequence or order of the four base pairs for a species.  If you thus have the sequence of the DNA barcode, it can tell you what the species is, similar to barcodes on items you buy in a store telling the teller machine what it is. 

   DNA barcoding works best when the taxonomy and relationships of a group of species or genera are already sorted out so that samples of a species can be grouped in the correct species (the barcodes must be already available to compare your sequence with).  The known species in an area or country, or a genus, must also all be sequenced or barcoded so that you have the complete collection available against which you can compare your sequence against. 

   Unfortunately in South Africa, very few of our macrofungi have been sequenced, and there are still so many new species that we cannot yet identify all of our species just by sequencing them.  This is because their DNA barcodes are not yet in the system and we will only get the DNA barcodes of species that are almost the same.  In a sense we are still building our “library records” so that we can effectively search it for a particular “book” or barcode we are looking for. However, DNA barcodes helps in the case of new species to guide researchers towards a possible identity because the sequence will tell you what species or genus will be most similar, thus providing a starting point for further study.  At this stage sequencing the DNA of a macrofungus is thus not a foolproof method to identify it.

   Phylogenetic studies compare species, or even genera, families, orders and kingdoms, to each other to determine how they are related (closely or far). These also give information if things belong in the same species or genus and thus represent a form of identification.  Since DNA sequence data have been used for such comparisons, a great number of changes occurred for the classification of fungi.  Such analyses showed the more accurate family or even order where a species should belong, showed that some genera or species should become more than one genus or species, while in other cases different species or genera became one.  This obviously lead to numerous changes in names (previous section) that did not always appear to make sense.  However, the more fungi are added to such datasets, the clearer the overall picture becomes of how the various fungi are related, and what characteristics or processes really dictates these relationships.