Chxout is a long established brand of Complement Genomics Ltd. The brand has a passion for the natural world and bridging the gap between science and nature to the public. Chxout also has a long history with falconry through bird sexing and more recently peregrine parentage.
The Internal Transcribed Spacer (ITS) is a stretch of ribosomal DNA (rDNA), present across all members of the fungi kingdom. Over time, evolution has allowed the ITS region to become incredibly divergent between species. Because of this variation, analysing the ITS region allows scientists to accurately identify fungal species by comparing their DNA sequences. Labelled in the diagram are the ITS1 and ITS4 primers, commonly used to target this area.
For some closely related species, or groups (known as species complexes), ITS analysis alone may not be sufficient evidence to give a confident species match.
In these special cases, additional testing can be run, using primers targeting additional regions of the genome. By analysing more than one site, we gain a deeper insight into the organism’s identity.
A common secondary target is the Large Ribosomal Subunit, specifically Regions 1 and 2 (D1/D2 LSU). In many yeasts, such as Cryptococcus neoformans, the ITS region evolves incredibly rapidly, making it more difficult to distinguish between species. The D1/D2 LSU develops at a slower rate, providing a more insightful view of the genetic code and species match.
Similarly, many fusiform fungal species are famously tricky to identify through ITS analysis alone. The gold standard here is to target the Translation Elongation Factor 1-alpha gene (TEF-1α), using complementary primers
