Genomics
Genomics studies the complete genetic content of organisms, sequencing entire genomes, mapping their structure and function, and comparing them across species to read evolution and biology at whole-genome scale.
Definition
Genomics is the branch of genetics concerned with the sequencing, structure, function, evolution, and editing of the entire genetic complement of an organism rather than individual genes in isolation.
Scope
This area covers the technologies and strategies for sequencing and assembling genomes, the organization and content of genomes including genes, repetitive elements, and regulatory regions, the functional annotation of genomes and the comparison of genomes across species, and the technologies for deliberately editing and engineering genomes. It treats biology at the scale of whole genomes; the inheritance of individual genes and the fine mechanics of expression are covered in neighboring areas.
Sub-topics
Core questions
- How are whole genomes sequenced and assembled from short reads of DNA?
- How are genomes organized, and how much of them codes for proteins versus other functions?
- How is the function of genomic elements inferred, and what does comparison across species reveal?
- How can genomes be edited precisely, and what does that capability enable?
Key theories
- Whole-genome sequencing and assembly
- By fragmenting DNA, sequencing the pieces, and computationally reassembling overlapping reads, the complete sequence of a genome can be reconstructed, the approach that produced the human genome.
- Comparative genomics
- Aligning the genomes of different species reveals conserved sequences, which tend to be functionally important, and lineage-specific changes, providing an evolutionary read-out of genome function.
Clinical relevance
Genomics underlies precision medicine, the diagnosis of rare and inherited disorders by whole-genome and exome sequencing, cancer genome profiling to guide therapy, pathogen surveillance, and the genome-editing tools now entering the clinic.
History
Sanger's sequencing method in the 1970s made reading DNA practical, the Human Genome Project delivered the first human reference sequence in 2001, next-generation sequencing then slashed costs by orders of magnitude through the 2000s, and CRISPR-based editing from 2012 onward gave genomics a precise way to rewrite as well as read genomes.
Key figures
- Frederick Sanger
- Eric Lander
- Craig Venter
- Jennifer Doudna
Related topics
Seminal works
- lander2001
- brown2018
Frequently asked questions
- What is the difference between genetics and genomics?
- Genetics traditionally studies individual genes and their inheritance, whereas genomics studies the whole genome at once, including how its many genes, regulatory elements, and non-coding regions interact and how genomes differ across individuals and species.
- What does it mean to assemble a genome?
- Sequencing reads only short fragments of DNA, so assembly is the computational process of finding overlaps among millions of fragments and stitching them into the long, ordered sequences that represent each chromosome.