Genome Sequencing in India

CSIR (Council of Scientific and Industrial Research) plans to undertake genome sequencing of a sample of nearly 1000 Indian rural youth to determine unique genetic traits, susceptibility (and resilience) to disease.

• This is the first time that such a large sample of Indians will be recruited for a detailed study.
• These recruited youths, as part of genome-sample collections, are representative of the country’s population diversity.
  • In this case, the bulk of them will be college students, both men and women, and pursuing degrees in the life sciences or biology.
• The project is an adjunct to a much larger government-led programme, still in the works, to sequence at least 10,000 Indian genomes.

Genome Sequencing 

• Genome sequencing is figuring out the order of DNA nucleotides, or bases, in a genome—the order of Adenine, Cytosine, Guanines, and Thymine that make up an organism's DNA.
• Human genome
  • It is made up of 23 chromosome pairs with a total of about 3 billion DNA base pairs.
  • There are 24 distinct human chromosomes: 22 autosomal chromosomes, plus the sex-determining X and Y chromosomes.
  • Chromosomes 1-22 are numbered roughly in order of decreasing size.
  • Somatic cells usually have one copy of chromosomes 1-22 from each parent, plus an X chromosome from the mother and either an X or Y chromosome from the father, for a total of 46.
  • There are estimated 20,000-25,000 human protein-coding genes.
  • The estimate of the number of human genes has been repeatedly revised down from initial predictions of 100,000 or more as genome sequence quality and gene finding methods have improved, and could continue to drop further.

Importance of Genome Sequencing

• Sequencing the genome is an important step towards understanding it.
• The genome sequence will represent a valuable shortcut, helping scientists find genes much more easily and quickly. A genome sequence does contain some clues about where genes are, even though scientists are just learning to interpret these clues.
• Scientists also hope that being able to study the entire genome sequence will help them understand how the genome as a whole works—how genes work together to direct the growth, development and maintenance of an entire organism.
• Finally, genes account for less than 25 percent of the DNA in the genome, and so knowing the entire genome sequence will help scientists study the parts of the genome outside the genes. This includes the regulatory regions that control how genes are turned on and off, as well as long stretches of "nonsense" or "junk" DNA—so called because significance of it hasn’t been established.