Genomics introduction
The objective of omics sciences is to identify, characterize, and quantify all biological molecules that are involved in the structure, function, and dynamics of a cell, tissue, or organism. Genomics – one of several omics branches of biological study can be understood as the study of whole genomes of organism and incorporates elements from genetics. Genomics is the science that studies the structure, function, evolution, and mapping of genomes and aims at characterization and quantification of genes, which direct the production of proteins with the assistance of enzymes and messenger molecules. It uses a combination of recombinant DNA, DNA sequencing methods and bioinformatics to sequence, assemble and analyse the structure and function of genomes.
- Comparative genomics: Study of the relationship of genome structure and function across different biological species or strains.
- Functional genomics: Describes gene and protein functions and interactions (often uses transcriptomics).
- Metagenomics: Study of metagenomes, i.e., genetic material recovered directly from environmental samples.
Diagram illustrating genomics
General schema showing the relationships of the genome, transcriptome, proteome, and metabolome (lipidome)
- Transcriptomics is the study an organism’s transcriptome, (sum of all of its RNA transcripts). Organism genetic information stored in the DNA of its genome is expressed through transcription
- Proteomics is the science that studies those proteins as related to their biochemical properties and functional roles, and how their quantities, modifications, and structures change during growth and in response to internal and external stimuli.
- The metabolome represents the collection of all metabolites in a biological cell, tissue, organ, or organism, which are the end products of cellular processes. Metabolomics is the science that studies all chemical processes involving metabolites.
Types of Genomics
Structural genomics
Aims to determine the structure of every protein encoded by genome. It determines the size of the genome of a species in mega-bases [Mb] and also the genes present in the entire genome of a species. Gene mapping, Genome annotation (Characterizing genomic features using computational and experimental methods), genetic map and cytological mapping. Structural genomics seeks to describe the 3-dimensional structure of every protein encoded by a given genome.
Functional genomics
Aims to collect and use data from sequencing for describing gene and protein function. It deals with transcriptome (complete set of RNAs transcribed from a genome) and proteome (complete set of proteins encoded by a genome). Functional genomics focuses on the dynamic aspects such as gene transcription, translation, and protein–protein interactions
Comparative genomics
Aims to compare genomes from different species. Analyses between species and strains
Classification of Genomics
The genomics can be classified as plant genomics, animal genomics, eukaryotic genomics and prokaryotic genomics.
Genomics: shaped by technology
Applications of Genomics
- Predicting diseases
- Diagnosis of infectious diseases
- DNA sequencing has widespread applications in DNA profiling, forensic sampling and identification, and paternity testing.
- Sequencing of microorganisms to engineer resistant genes in crops. Mapping and whole-genome sequencing of food plants to increase productivity and nutritional contents as well as environmental tolerance.
- Study of genotypes, genes, and proteins; gene-based studies of cancers; construction of endonuclease maps; detection of mutations; construction of molecular evolution map, and transcriptome profiling
The BLAST sequence alignment program
Limitations of Genomics
These days, the genome mapping of crop plants is gaining increasing importance. It has several useful applications as discussed above. However, there are some limitations of genome mapping such as
- high cost,
- high technical skill,
- laborious work,
- availability of limited genes and
- lake of proper markers.
List of omics topics in biology
-Ome | Field of study (-omics) | Collection of | Notes |
Epigenome | Epigenomics | Epigenetic modifications | Epigenomics is the study of the complete set of epigenetic modifications on the genetic material of a cell, collectively known as the epigenome |
Genome | Genomics | DNA sequences/Chromosomes | Genomics is an interdisciplinary field of biology focusing on the structure, function, evolution, mapping, and editing of genomes. A genome is an organism’s complete set of DNA, including all of its genes as well as its hierarchical, three-dimensional structural configuration |
Proteome | Proteomics | Proteins | Proteomics is the large-scale study of proteins. The proteome is the entire set of proteins produced or modified by an organism or system. |
Transcriptomics | Transcriptomics | All RNA molecules including mRNA, rRNA, tRNA and other ncRNAs | Transcriptomics is the study an organism’s transcriptome, (sum of all of its RNA transcripts). Organism genetic information stored in the DNA of its genome is expressed through transcription |
Metabolome | Metabolomics | Metabolites | All products of a biological reaction (including intermediates) |
Metagenome | Metagenomics | Genetic material found in an environmental sample | Metagenomics is the study of genetic material recovered directly from environmental or clinical samples by a method called sequencing. |
References
- Vailati-Riboni, M., Palombo, V., & Loor, J. J. (2017). What are omics sciences? In Periparturient Diseases of Dairy Cows: A Systems Biology Approach (pp. 1-7). Springer. https://doi.org/10.1007/978-3-319-43033-1_1
- wikipedia
- wikipedia.org/wiki/Omics
- 01_genomics_comp_genomics_v2 (jhu.edu)