Genome walking

Genome Sequence

A genome sequence is the complete list of the nucleotides (A, C, G, and T for DNA genomes) that make up all the chromosomes of an individual or a species. Within a species, the vast majority of nucleotides are identical between individuals, but sequencing multiple individuals is necessary to understand the genetic diversity.

History

The first complete genome sequence of a free living organism, Haemophilus influenzae, was completed in 1995 by The Institute for Genomic Research (TIGR). This marked the beginning of a new era in genomic research. The first human genome sequence was completed in 2003 by the Human Genome Project.

Sequencing Methods

There are several methods for sequencing genomes. The most commonly used methods are Sanger sequencing and Next Generation Sequencing (NGS). Sanger sequencing, also known as the "chain termination method," is a method of DNA sequencing based on the selective incorporation of chain-terminating dideoxynucleotides by DNA polymerase during in vitro DNA replication. NGS, on the other hand, allows for sequencing of the entire genome in a single process, making it a faster and more efficient method.

Applications

Genome sequencing has a wide range of applications. It is used in genetic testing, personalized medicine, forensic biology, conservation biology and agriculture. In medicine, genome sequencing allows for the identification of genetic variants that cause disease or influence its progression or response to treatment.

Challenges

Despite the many advances in genome sequencing, there are still many challenges. These include the high cost of sequencing, the difficulty of interpreting the data, and the ethical issues related to genetic privacy and discrimination.

See Also

• Genomics
• DNA sequencing
• Human Genome Project
• Next Generation Sequencing