Scientists have reached a landmark point in one of the world's most important scientific projects by sequencing the last chromosome in the Human Genome, the so-called “book of life”.
Chromosome 1 contains nearly twice as many genes as the av
| SMART BOX
• Chromosomes, found in the
nucleus of a cell, are thread-like
structures that contain genes
which determine the
characteristics of an individual
• The human genome has an
estimated 20,000 to 25,000
• The sequencing of chromosome
1 has led to the identification of
more than 1,000 new genes
erage chromosome and makes up eight percent of the human genetic code. It is packed with 3,141 genes and linked to 350 illnesses including cancer, Alzheimer's and Parkinson's disease.
“This achievement effectively closes the book on an important volume of the Human Genome Project,” said Dr Simon Gregory who headed the sequencing project. The project was started in 1990 to identify the genes and DNA sequences that provide a blueprint for human beings.
Chromosome 1 is the biggest and contains the greatest number of genes. “Therefore it is the region of the genome to which the greatest number of diseases have been localised,” added Gregory, from Duke University in the US.
The sequence of chromosome 1, which is published online by the journal Nature, took a team of 150 British and American scientists 10 years to complete.
Researchers around the world will be able to mine the data to improve diagnostics and treatments for cancers, autism, mental disorders and other illnesses.
Each chromosome is made up of a molecule of DNA in the shape of a double helix which is composed of four chemical bases represented by the letters A (adenine), T (thymine), G (guanine) and C (cytosine). The arrangement, of the letters determines the cell's genetic code.