First Artificially Genome

• The first artificially created genome was for the virus Phi X 174, synthesized by a team led by Craig Venter using a method called Polymerase Chain Assembly (PCA). 
• This achievement laid the foundation for today’s synthetic genome research.

What is a Synthetic Genome?

• A synthetic genome is an artificially constructed set of genetic instructions (DNA) that mimics or modifies the natural genome of an organism.
• Unlike traditional genetic editing—where small changes are made to existing DNA—synthetic genomics involves building entire sequences of DNA from scratch using chemical processes.

Methods to Create Synthetic Genomes

1. Chemical DNA Synthesis
   • Short DNA fragments (called oligonucleotides) are chemically synthesized in labs.
   • These are then assembled into longer sequences using enzymatic or physical methods. 
2. Gene Assembly Techniques
   • Overlapping synthetic fragments are stitched together using polymerase cycling assembly (PCA) or Gibson assembly.
   • These methods allow researchers to construct entire genes or chromosomes in a stepwise manner.
3. In Vitro and In Vivo Assembly
   • DNA segments may be assembled outside cells (in vitro) or inserted into host organisms like yeast (in vivo) for natural assembly and replication.
   • Yeast is commonly used due to its ability to stably maintain and replicate large DNA constructs.
4. Error Correction and Validation
   • As synthetic DNA is prone to errors, multiple rounds of sequencing and correction are done to ensure accuracy and function.
5. Functional Testing
   • The synthetic DNA is introduced into cellular systems to test whether it behaves like natural DNA—e.g., whether it produces proteins or regulates other genes correctly.

Human Genome Project (HGP)

• Timeline: 1990–2003
• Goal: To map and sequence all human genes – identifying the complete set of DNA in humans.
• Outcome: Revolutionized genomics, paved the way for genomic medicine, and enabled rapid identification of disease genes.

India Genome Project

• Launched by: Department of Biotechnology (DBT), Government of India
• Objective: To sequence the genomes of thousands of Indians to understand the genetic diversity of the population.
• Purpose:
  • Enables precision medicine in the Indian context.
  • Helps in identifying disease susceptibility and response to drugs among Indian sub-populations.
  • Promotes indigenous genomic research capacity.