BharatNotes What is Genome Sequencing?
Genome sequencing determines the precise order of the four nucleotide bases — adenine (A), thymine (T), guanine (G) and cytosine (C) — across an organism's entire DNA. The human genome contains about 3 billion such base pairs. Whole-genome sequencing (WGS) reads all of this at once, allowing scientists to map genes, detect mutations and study the variations that distinguish individuals and populations.
The benchmark effort was the Human Genome Project (1990–2003), an international consortium that produced the first human reference genome. Its finished sequence covered about 99% of the gene-containing (euchromatic) region with 99.99% accuracy and identified an estimated 20,000–25,000 genes (genome.gov).
How It Works and Why Costs Fell
Modern next-generation sequencing (NGS) breaks DNA into fragments, reads them in parallel, and reassembles the data computationally. This parallelism collapsed both time and cost: sequencing fell from around USD 10 million per megabase in 2001 to a fraction of a cent today, making population-scale projects feasible.
Key Applications
| Application | What it enables |
|---|---|
| Precision medicine | Tailoring diagnosis and drugs to a patient's genetic profile |
| Disease prediction | Identifying markers for inherited and lifestyle disorders |
| Genomic surveillance | Tracking pathogen variants (e.g. SARS-CoV-2) in real time |
| Agriculture | Developing higher-yield, climate-resilient crops |
| Conservation | Studying biodiversity and endangered-species genetics |
India's Genomics Push
Genome India Project (GIP): Initiated by the Department of Biotechnology (DBT) on 3 January 2020 and led by the Centre for Brain Research, IISc Bengaluru, with about 20 collaborating institutions. It aimed to build a reference database of genetic variation reflecting India's diversity. On 9 January 2025, the government announced completion of sequencing 10,000 Indian genomes and made the data accessible to researchers; sequencing data for 9,648 samples and phenotypic data for 17,777 samples are archived at the Indian Biological Data Centre (IBDC) in Faridabad (PIB, 9-Jan-2025). The minister also announced a future target of sequencing 10 million genomes. Sampling spanned over 99 ethnic groups, with roughly 36.7% rural, 32.2% urban and 31.1% tribal representation (PIB, Jan-2025).
INSACOG: The Indian SARS-CoV-2 Genomics Consortium was established on 30 December 2020 as a multi-agency network to monitor genomic variations in the coronavirus. It began with 10 genome-sequencing laboratories and was later expanded, and is jointly steered by the Ministry of Health & Family Welfare and DBT, with ICMR and CSIR (PIB).
UPSC Angle
For Prelims, anchor the facts: GIP is a DBT initiative, completed its 10,000-genome milestone (announced Jan 2025), with data at IBDC Faridabad; INSACOG handles pathogen surveillance. For Mains GS3, balance the promise of precision medicine, indigenous research capacity and food security against ethical concerns — genetic data privacy, potential discrimination, and equitable access. Link it to current affairs on biotechnology and public health for value-added answers.
