Internal Transcribed Spacer (ITS) as Dna Barcoding to Identify Fungal Species: a Review

Abstract

Despite the fact that fungi are important sources of both bioactive compounds and mycotoxins, and that they are very ubiquitous in our environment, their species identification is hampered by incomplete and often unclear literature. Fungi identification is primarily based on their phenotypic and physiological characteristics. Nowadays, many molecular methods to identify fungal species have been developed. One of the methods considered as a new concept to rapidly and accurately identify unknown fungal sample is DNA Barcoding. This literature review will outline the use of DNA barcoding approach to rapidly identify fungal species and the use of ITS region that recently has been designated as primary DNA barcode for fungal kingdom. "DNA barcode" is a short, highly variable and standardized DNA region with approximately 700 nucleotides in length, which is used as a unique pattern to identify living things. Internal Transcribed Spacer (ITS) region of nuclear DNA (rDNA) has become the most sequenced region to identify fungal taxonomy at species level, and even within species. ITS region is a highly polymorphic noncoding region with enough taxonomic units. Therefore, it is able to separate sequences into species level. Even though ribosomal ITS as a universal barcode marker for fungi is still hampered by few limitations, the ITS will remain as the key choice for fungal identification. The search for alternative regions as DNA marker to improve fungal identification, especially in specific heredities, has already started.

Development of loop-mediated isothermal amplification (LAMP) assay for detection of Pseudocercospora angolensis in sweet orange

“…The region from which the primer is designed should be conserved and unique to the target species [16]. The ITS region is very useful in identifying fungi at species level hence it is the primary barcode for the fungal kingdom [22]. That explains why in this study, the ITS1, 5.8S, ITS2 and partial sequence of the large subunit ribosomal RNA in the genome of P. angolensis were used to design both PCR and LAMP primers.…”

<i>Candida</i> species: the silent enemy

“…In fungi, ITS1 and ITS2 are located in the rDNA gene complex between the 18s and 5.8s rRNA and 5.8s and 26s rRNA genes respectively (32). These regions are distinguished by their variations among fungal species and have therefore been selected as DNA barcode to differentiate the fungal species (33). Leaw et al, have demonstrated the candidate ITS regions for Candida species identification.…”

Isolation and Identification of Fungi from Clinical Samples of Diabetic Patients and Studying the Anti-Fungal Activity of Some Natural Oils on Isolated Fungi

“…This method serves the rapid identification of fungi and other organism at species level. The ITS region is the most widely sequenced region in DNA used for the identification of fungi (22) and has been recommended as the universal fungal barcode sequence (23).…”