Genomics is the study of the structure and function of genomes.
Some genomics areas of research are:
- Functional genomics
- Structural genomics
- Epigenetics
- Metagenomics
The definition of genomics includes related disciplines such as proteomics, metabolomics and bioinformatics.
What is a genome?
A genome is an organism’s complete set of genetic instructions. Each genome contains all of the information needed to build that organism and allow it to grow and develop. As an example, the human genome is made up of 22 autosomes and a pair of sex chromosomes.
A genome sequence is establishing the order of DNA nucleotides or bases (A, C, G, and T) that make up an organism's DNA. This information is invaluable to understanding development.
DNA code. Photo: Wellcome Institute
DNA
DNA contains all of the information that is required to make an organism and keep it running. Like a recipe book, it holds the instructions for making all the proteins in our bodies and has many other activities. DNA is a long molecule that contains our unique genetic code, made up of base-pairs of letters – As, Cs, Gs, and Ts. The human genome has 3.2 billion base pairs.
Genes and genetics
A gene is a section of DNA within the genome that is inherited. Genes carry information to make a molecule, usually a protein, which contains the instructions for our individual characteristics, like eye and hair colour. Humans for instance have 20,000 to 21,000 genes in our genome.
Genetics is the study of genes and their roles in inheritance – how certain traits or conditions are passed down from one generation to another.
What is genomics used for?
Genomics is a knowledge resource; its ongoing value is in generating further understanding. The genome is a map in which researchers from many different fields, including medicine, can utilise specific information that explains individual genetic factors for developing technologies to target issues of interest. In human health for instance, genomic information is currently being used to improve some diagnosis and treatment options, including tumour DNA sequencing and analysis, understanding disease, and developing better DNA-based therapies.
How are genomes generated?
Current technology means the whole genome can't be produced in its entirety – researchers therefore have to work with small pieces of the genome, then reassemble them into the proper order.
- DNA is extracted from an organism in the laboratory and is broken into manageable segments of base pairs. These sequences are read by an automated sequencing machine.
- DNA sequences are then assembled in the correct order to produce a whole genome assembly. This is done using computer software to identify overlaps in the DNA segments.
- Genome variation analysis is the next step. Software is used to compare DNA sequences within the species to locate the differences that make an individual unique.
All of this valuable data is stored in in a database for other researchers to potentially access for further studies and applications.
What is the difference between a draft genome and a whole genome?
A draft genome is the first assembly, usually performed in an automated way. There is need for further analysis to build it up into a whole genome, which is likely to have gaps of DNA that need further sequencing and/or analysis.
Genetic variation
Genetic variation is a term used to describe the variation in the DNA sequence in a genome when one genome is compared to another. Genetic variation is what makes us unique. When genetic variants give us a particular advantage they are more likely to be passed on to future generations.
A genome-wide association study (or “GWAS” for short) involves scanning many genomes to find common genetic variations associated with a particular characteristic. This is not an easy task as it takes considerable bioinformatics to perform.
Bioinformatics
Bioinformatics is the development of methods and software tools for understanding the biological data derived from genomics. It is vital as it provides ways of making use of the enormous amounts of data generated by each sequencing project. Genomics Aotearoa is creating a national collaborative platform to help scientists manage and analyse genomic data.
Storing and sharing data
Genomes are made up of a series of base pairs in a defined order; this code information is stored on a computer database to potentially be available for further analysis.
Many databases have traditionally been a public repository for researchers to access so they can utilise the information for their own research. Genomics Aotearoa has taken a managed access approach and is overseeing the development of a New Zealand genomics data repository that will include appropriate access protocols within a Māori values context that respects taonga. This builds on the research guidelines Te Ara Tika, Te Mata Ira and He Tangata Kei Tua.