Describe how the team from the J. Craig Venter Institute created a synthetic genome. How did the team demonstrate that the genome converted the recipient strain of bacteria into a different strain?

Verified step by step guidance

1. Understand that the J. Craig Venter Institute team aimed to create a synthetic genome by chemically synthesizing the entire DNA sequence of a bacterial genome from scratch, rather than copying it from an existing organism.
2. Recognize that the team first determined the complete DNA sequence of the target bacterium (Mycoplasma mycoides) and then used automated DNA synthesis techniques to build small fragments of DNA, which were subsequently assembled into larger segments through a series of molecular cloning steps.
3. Note that these larger DNA segments were progressively combined using yeast cells as a host for assembly, ultimately resulting in a full-length synthetic genome that matched the natural genome sequence but was chemically synthesized.
4. Understand that to demonstrate functionality, the synthetic genome was transplanted into a recipient bacterial cell (Mycoplasma capricolum) whose own DNA had been removed or inactivated, effectively replacing its genome with the synthetic one.
5. Observe that the recipient cells began to exhibit the characteristics and behaviors of the donor species (Mycoplasma mycoides), proving that the synthetic genome was capable of directing cellular functions and converting the recipient strain into a new strain.

Key Concepts

Synthetic Genome Construction

Synthetic genome construction involves chemically synthesizing DNA sequences in the laboratory to create an entire genome from scratch. The Venter Institute team assembled short DNA fragments into larger segments, eventually building a complete bacterial genome. This process requires precise sequencing and assembly techniques to ensure the synthetic genome matches the natural one.

Genome Transplantation

Genome transplantation is the process of inserting a synthetic genome into a recipient cell whose original DNA has been removed or inactivated. The Venter team transplanted their synthetic genome into a bacterial cell, effectively replacing its native genome. This step is crucial to test whether the synthetic genome can control the cell's functions and replication.

Phenotypic Conversion as Evidence of Genome Function

Phenotypic conversion refers to the change in observable traits of the recipient bacteria after receiving the synthetic genome. The Venter team demonstrated that the recipient strain adopted the characteristics of the donor genome, such as colony appearance and growth behavior, proving that the synthetic genome was functional and directed the cell's biology.