Vector Delivery

In molecular biology, a vector is a vehicle that is used to deliver genetic material to a target cell via horizontal gene transfer

There are several methods for transferring genetic material, but all mechanisms can be classed as either viral or non-viral

Non-Viral Delivery

A commonly used vector is a plasmid – a circular DNA molecule capable of self-replication and autonomous protein expression

Plasmids can be introduced to target cells by a variety of means, including:

  • Electroporation – An electric current is applied to make temporary holes in the cell membrane
  • Heat shocking – Thermal energy is used to briefly destabilise the cell membrane to allow for vector entry
  • Particle bombardment – DNA-coated particles are shot into the cells by a gene gun
  • Microinjection – A glass micropipette is used to inject the vector directly into the cell
  • Lipofection – The vector is transferred within a liposome (a vesicle capable of fusion with the cell membrane)

Viral Delivery

The insertion of a viral vector into a cell is called transduction and utilise the ability of a virus to inject its DNA into a host cell

Viruses integrate their DNA directly into the host genome, which can have both beneficial and detrimental consequences

  • The advantage of this practice is that protein synthesis will be driven by endogenous expression patterns
  • A disadvantage of this practice is that there is a risk the random insertion into the genome will abrogate key host genes

Viruses can have either a DNA genome (adenovirus) or an RNA genome (retrovirus)

  • Retroviruses use an enzyme called reverse transcriptase to convert the RNA sequence into a DNA copy prior to integration

Overview of Viral Delivery (Adenovirus)

viral gene delivery