Degradome Sequencing

Partial results are shown below:

Sequencing quality distribution

A/T/G/C Distribution

IGV Browser Interface

Correlation Analysis Between Samples

PCA Score Plot

Venn Diagram

Volcano Plot

Statistics Results of GO Annotation

KEGG Classification

1. What is the principle of degradome sequencing?

In animals, protein repression is believed to occur by translational inhibition along with mRNA degradation. In plants, miRNAs degrade their mRNA targets by precise cleavage between the 10th and 11th nucleotide s from the 5' end of the miRNA in the complementary region of the target transcript, generating a distinct peak of degradome sequence tag at the predicted cleavage site relative to other regions of the transcript. Based on this principal, the degradome sequencing is primarily used to globally identify remnants of small RNA-directed cleavage by sequencing the 5' ends of uncapped RNAs in plants.

2. What are the advantages of degradome sequencing for identification of miRNA targets?

Table 1. The comparison of degradome sequencing and traditional methods for miRNA target prediction.

3. How is degradome sequencing different from other RNA sequencing methods?

Degradome sequencing specifically focuses on RNA degradation products, while other RNA sequencing methods like RNA-Seq typically analyze the entire transcriptome. This makes degradome sequencing uniquely suited for studying miRNA/siRNA-mediated RNA cleavage events.

Reference

1. Riffo-Campos, Á.L., et al. Tools for sequence-based miRNA target prediction: What to choose?. International journal of molecular sciences, 2016, 17(12): 1987.

Small RNA and degradome sequencing reveals important microRNA function in Astragalus chrysochlorus response to selenium stimuli

Journal: Plant biotechnology journal
Impact factor: 6.305
Published: 21 May 2015

Abstract

Astrgalus species are known as hyperaccumulator of Se by converting it to nonaminoacid compounds. But we have no idea about the Se-metabolism-related hyperaccumulation. The authors attempted to understand whether miRNAs play a role in Se accumulation in plants. In this study, they identified 418 known miRNAs and 151 novel miRNAs induced by Se exposure in Astragalus chrysochlorus. Through deep degradome sequencing the authors revealed important miRNA function in A. chrysochlorus response to selenium stimuli.

Materials & Methods

Results

1. miRNA identification and expression profiles.

A total of 418 known and 151 novel miRNAs was identified. The distribution of miRNAs between control and Se treatment is depicted in figure 1. The 418 miRNAs belong to 380 miRNA families, and 160 miRNA families were differently expressed in both control and Se-treated samples. 30 novel miRNAs were differently expressed after Se treatment.

Figure 1. Distribution of miRNAs between control and Se treatment: (a) conserved miRNAs; (b) novel miRNAs.

Figure 2. Small RNA expression profiles of control and Se-treated callus of A. chrysochlorus.

Figure 3. Expression profiles of randomly selected miRNAs with different abundance in Se-treated A. chrysochlorus calli. A total of 1339 predicted sites were identified and determined to be cleaved by 499 miRNAs. The target genes were annotated and classified as transcription factors and their subunits, enzyme coding genes, resistance proteins, leucine-rich repeat, leucine zipper, zinc finger proteins, and other structural and functional proteins.

Figure 4. Target plots (t-plots) of miRNAs and their targets. The red arrows indicate the most abundant peaks or cleavage sites. (a) miR162-3p targeting endonuclease Dicer homologue-1-like protein; (b) miR1513a targeting blue light-activated histidine kinase; (c) miR2118b targeting hypoxanthine-guanine phosphoribosyltransferase-like protein; (d); miR172c targeting putative ethylene-responsive transcription factor RAP-2-7-like protein; (e) miR159b-3p targeting hypothetical protein 11M9.5; (f) miR166 h-3p targeting homeobox leucin zipper protein ATHB-15-like protein.

3. GO and KEGG pathway analyses

The targets of identified miRNAs were subjected to GO and KEGG analysis to perceive their biological roles. The target genes are involved in 47 types of cellular component, 103 types of molecular function and 144 types of biological process.

Figure 5. GO classifications of miRNA targets in A. chrysochlorus.

Figure 6. KEGG plant-pathogen interaction pathway and novel and known miRNAs which obtained in this study possibly targeting the genes involved in this pathway.

Reference

1. Cakir O, Candar-Cakir B, Zhang B. Small RNA and degradome sequencing reveals important microRNA function in Astragalus chrysochlorus response to selenium stimuli. Plant biotechnology journal, 2016, 14(2): 543-556.