Thekey difference在ITS1和ITS2之间is that ITS1 is a spacer DNA located between 18S and 5.8SrRNAgenes ineukaryotes, while ITS2 is a spacer DNA located between 5.8S and 28S rRNA genes in eukaryotes.
Internal transcribed spacer (ITS) is the spacer DNA usually located between small subunit ribosomal RNA and large subunit ribosomal RNA genes in the chromosome or in the corresponding transcribed region in the polycistronic rRNA precursor transcript molecule. Inbacteria and archaea, there is only a single ITS between 16S and 23S rRNA genes. But in eukaryotes, there are two ITS spacer DNA: ITS1 (between 18S and 5.8S rRNA genes) and ITS2 (between 5.8S and 28S rRNA). Therefore, ITS1 and ITS2 are two spacer DNA found between rRNA genes in eukaryotes.
内容
1.Overview and Key Difference
2.What is ITS1
3.What is ITS2
4.Similarities – ITS1 and ITS2
5.ITS1 vs ITS2 in Tabular Form
6.概括
What is ITS1?
ITS1是位于真核生物中18s至5.8s rRNA基因之间的间隔DNA。它是指位于rRNA基因之间的一块非功能间隔DNA。ITS1的长度变化大于ITS2。ITS1的长度变化大约为(200-300bp)。它的标记(例如ITS1)证明了它们在阐明不同分类单元之间的系统发育关系方面的效率。此外,ITS1间隔DNA比IT2间隔DNA保守。ITS1结构仅在较小的分类单元中保守。每个真核核糖体簇还包含称为外部转录间隔物(5'和3'ETS)的区域。
The ITS1 spacer DNA is very close to the 5’external transcribed spacer (5’ ETS). Furthermore, if anyone wants to amplify the ITS1 region for phylogenetic relationship studies, they have to use a specific primer pair (reverse and forward primers) for this purpose. To amplify ITS1 region, two primer sets are normally used in the PCR protocols of laboratories. They are ITS1 forward and ITS2 reverse or ITS1 foward and ITS4 reverse.
What is ITS2?
ITS2是位于真核生物中5.8s和28s rRNA基因之间的间隔DNA。IT2区域的长度变化比ITS1区域短。IT2的长度变化大约为(180-240bp)。但是,在许多分类单元中,ITS2区域比ITS1地区更保守。它确定所有ITS2序列都共享二级结构的共同核心。此外,所有被子植物中有40%的ITS2区域是保守的,而可以使整个家庭和更高水平的ITS2区域的50%保持一致。
Regardless of the scope of conservation, usage of ITS2 region also very popular such as ITS1 region in phylogenetic relationship studies, especially in fungal DNA barcoding. To amplify ITS2 region, a specific primer set is generally used in the PCR protocols of laboratories. That is ITS1 foward and ITS4 reverse. But when PCR protocol uses this primer set, it also amplifies ITS1 region together with the ITS2 region. Further, the ITS2 spacer DNA is very close to the 3’external transcribed spacer (3’ ETS).
Similarities Between ITS1 and ITS2
- ITS1 and ITS2 are two spacer DNA located between rRNA genes.
- They are present only in eukaryotes.
- Both can be amplified by using specific primer pairs.
- They are both excised in rRNA maturation as non-functional by-products.
- Both are very important for phylogenetic relationship studies, especially in fungal DNA barcoding.
ITS1和ITS2之间的差异
ITS1 is a spacer DNA present between 18S and 5.8S rRNA genes in eukaryotes while ITS2 is a spacer DNA located between 5.8S and 28S rRNA genes in eukaryotes. So, this is the key difference between ITS1 and ITS2. Furthermore, ITS1 has greater length variation compared to ITS2. On the other hand, ITS2 has a shorter length variation compared to ITS1. This is another difference between ITS1 and ITS2.
The below infographic lists the differences between ITS1 and ITS2 in tabular form for side by side comparison.
概括– ITS1 vs ITS2
Internal transcribed region (ITS) is a non-functional piece of spacer DNA located between rRNA genes. In bacteria and archaea, there is only a single ITS region. But in eukaryotes, there are two ITS regions: ITS1 and ITS2. ITS1 is a spacer DNA that is located between 18S and 5.8S rRNA genes in eukaryotes, while ITS2 is a spacer DNA that is located between 5.8S and 28S rRNA genes in eukaryotes. Thus, this is the summary of the difference between ITS1 and ITS2.
Reference:
1.“”内部转录垫片”。概述| ScienceDirect Topics.
2. Schoch, Conrad L., et al. “Nuclear Ribosomal Internal Transcribed Spacer (ITS) Region as a Universal DNA Barcode Marker for Fungi.” PNAS, National Academy of Sciences.
Image Courtesy:
1.“”Eucaryot rdna” - 法老汉(Pharaoh Han)假设 - 没有提供机器可读的来源。假定自己的工作(基于版权索赔)(CC BY-SA 3.0)via Commons Wikimedia
2. “MolecularMarkersSymbiodinium” By Allisonmlewis – Own work(CC BY-SA 4.0)via Commons Wikimedia
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