Human Genome Project (HGP)
It was started in the year 1990 to map the entire human genome and completed in 2003. It was coordinated by the U.S. Department of Energy and the National Institute of Health along with many other research organizations in the world.
Its goals were;
- To identify all the genes in human DNA.
- To determine the sequence of 3 billion base pairs in human DNA.
- To store this information in databases.
- To address ethical, legal, and social issues (ELSI) that may arise from the project.
The methodologies of HGP are;
- Expressed sequence tags (ESTs): Focussed on identifying all genes that are expressed as RNA.
- Sequence annotation: Blind approach of sequencing the whole genome containing coding and non-coding sequences, needing vectors like BAC (Bacterial artificial chromosomes) and YAC (Yeast Artificial Chromosomes).
Process of HGP;
- The whole DNA from a cell is isolated
- Then it is converted into random fragments of relatively smaller sizes with the help of restriction enzymes.
- Those fragments are cloned in a suitable host (e.g.: bacteria and yeast) using specialized vectors (BAC and YAC) for amplification (now by PCR).
- The fragments are then sequenced using automated DNA sequencers (using the Frederick-Sanger method).
- These sequences were then arranged based on some overlapping regions present in them.
- Then all the sequences were aligned using computer programs.
- These sequences were subsequently annotated and were assigned to each chromosome.
Applications of HGP
- Biological systems can be well studied by the knowledge of DNA sequences.
- The Human Genome sequence was used to develop a new approach to biological research.
Also Read: Human Genome Project
Molecular Basis of Inheritance Notes Class 12
CBSE Class 12 Molecular Basis of Inheritance: Inheritance is transmitted by certain molecules that Mendel termed as ‘factors’, but their nature was discovered later with the development of various scientific techniques. The molecules which govern the inheritance are called genes and it is of two types; Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA). In all organisms except viruses, DNA acts as the genetic material whereas RNA acts as the messenger molecule, however in some viruses RNA functions as the genetic material. It is because DNA is a more stable molecule as compared to RNA and hence, it evolved as the genetic material of almost all the organisms.
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