The key difference between metagenomics and metatranscriptomics relies on the type of biomolecules studied in each area. Metagenomics studies DNA, its sequences and its behaviour in organisms, while metatranscriptomics studies the transcribed DNA, mainly mRNA sequences and its behaviour in organisms.
Metagenomics and metatranscriptomics are two fields that have gained much popularity over the years in relation to the microbial community. They are important in the health care, industry and agricultural biotechnology. Both metagenomics and metatranscriptomics allow the study of individual organisms in a community and their functional roles that are either beneficial or harmful.
CONTENTS
1. Overview and Key Difference
2. What is Metagenomics
3. What is Metatranscriptomics
4. Similarities Between Metagenomics and Metatranscriptomics
5. Side by Side Comparison – Metagenomics vs Metatranscriptomics in Tabular Form
6. Summary
What is Metagenomics?
Metagenomics is the field of study that explores Deoxyribonucleic acid (DNA). It is most relevant to the microbial community. Also, it is a more advanced field in comparison to genomics. In genomics, analysis of a particular organisms’ DNA takes place. However, metagenomics involves the analysis of genetic material across a community of organisms. Thus, this allows studying the behaviour of a community of organisms pertaining to one condition or one environment.
Figure 01: Metagenomics
The main technique involved in metagenomics studies is the Next Generation Sequencing (NGS) that uses the micro-array technology. The NGS methods can analyze multiple organisms in a single reaction for the presence or absence of specific DNA sequences. These DNA sequences may be responsible for a single disease condition or an environmental condition. Hence, using metagenomic knowledge, screening of organisms can be done easily and accurately. The sequencing during NGS takes place in short reads and the profiling of the organisms’ DNA takes place. The 16s DNA sequence is a popular sequence studied in metagenomics concerning microorganisms.
Following the sequencing of the community of organisms, the alignment of the sequences should be done. Tools such as the Basic Local Alignment Sequence tool (BLAST) are in use to fulfil the task of alignment. Following the alignment, a phylogenetic tree provides the relationship of each organism in the community and details regarding its behaviour.
What is Metatranscriptomics?
Metatranscriptomics is the field of study that deals with the transcriptome of an organism. The transcriptome constitutes the entire RNA sequences transcribed during DNA transcription. The mRNA sequences present in the transcriptome provide information on the genetic expression. Metatranscriptomics is the analysis of multiple transcriptomes across populations or communities.
Figure 02: Transcriptome Analysis
Metatranscriptomics studies also use microarray technologies to find the sequences of the short read sequences. Moreover, metatranscriptomics also involves a thorough bioinformatics analysis using alignment tools and tree designing methods. However, the field of metatranscriptomics is much harder in comparison to metagenomics. The extraction of mRNA or RNA as a whole is not as easy as it appears to be. Since RNA is highly prone to destruction and has a very short living time, the maintenance and the storage of these could be a possible query.
What are the Similarities Between Metagenomics and Metatranscriptomics?
- Metagenomics and metatranscriptomics are high throughput techniques to analyze communities of organisms, mainly microbial communities.
- Both techniques use microarray technology to deduce the findings.
- The obtained results are often analyzed using BLAST alignment and Phylogenetic trees.
- Moreover, both techniques do not focus on one organism, but a group or community organisms.
- Besides, both concepts are also studied mostly in relation to microbes – the main reason being their diverse roles played.
What is the Difference Between Metagenomics and Metatranscriptomics?
Metagenomics and Metatranscriptomics involve the analysis of genetic matter in a community of organisms. Thus, metagenomics concern the patterns and sequences of DNA whereas metatranscriptomics refer to the analysis of the mRNA or the transcribed DNA. So, this is the key difference between metagenomics and metatranscriptomics.
Moreover, the extraction procedure differs in both techniques; metagenomics involve DNA extraction procedures and metatranscriptomics involve RNA extraction procedures. Hence, this is also a significant difference between metagenomics and metatranscriptomics.
The below infographic summarizes the difference between metagenomics and metatranscriptomics:
Summary – Metagenomics vs Metatranscriptomics
Metagenomics and metatranscriptomics are novel fields of study which analyze a community of organisms for a particular condition. Thus, metagenomics refers to the analysis of DNA sequences. In contrast, metatranscriptomics refers to the analysis of RNA sequences or transcribed DNA products. In this regard, metatranscriptomics enables the identification of gene expression for a particular case. Both are important in analyzing mutations and their effects. These are rapid and more reliable techniques used in advance diagnosis. Thus, this is the summary of the difference between metagenomics and metatranscriptomics.
Reference:
1. Aguiar-Pulido, Vanessa, et al. “Metagenomics, Metatranscriptomics, and Metabolomics Approaches for Microbiome Analysis.” Evolutionary Bioinformatics Online, LibertasAcademica, 12 May 2016, Available here.
Image Courtesy:
1. “pcbi.1002808.g001” By Phylogeny Figures (CC BY 2.0) via Flickr
2. “Transcriptome fig 3” By Danny556 (talk) – self-made (C BY-SA 3.0) via Flickr