Paragraph 6 Characteristics of the vector

The vector should be well characterised

• For this purpose the following characteristics should be taken into account.

  1. (a)

     Information on composition and construction

     1. (i)

        the type of the vector should be defined (virus, plasmid, cosmid, phasmid, transposable element, minichromosome, etc.);

     2. (ii)

        the following information on the constituent fragments of the vector should be available—

        1. (aa)

           the origin of each fragment (progenitor genetic element, strain of organism in which the progenitor genetic element naturally occurred),

        2. (bb)

           if some fragments are synthetic, their functions should be known;

     3. (iii)

        the methods used for construction should be known.

  2. (b)

     Information on vector structure

     1. (i)

        the size of the vector should be known and expressed in basepairs or D;

     2. (ii)

        the function and relative positions of the following should be known—

        1. (aa)

           structural genes,

        2. (bb)

           marker genes for selection (antibiotic resistance, heavy metal resistance, phage immunity, genes coding for degradation of xenobiotics, etc.),

        3. (cc)

           regulatory elements,

        4. (dd)

           target sites (nic-sites, restriction endonuclease sites, linkers, etc.),

        5. (ee)

           transposable elements (including provirus sequences),

        6. (ff)

           enes related to transfer and mobilisation function (eg with respect to conjugation, transduction or chromosomal integration),

        7. (gg)

           replicon(s).

The vector should be free from harmful sequences

• The vector should not contain genes coding for potentially harmful or pathogenic traits (eg virulence determinants, toxins, etc.) unless for Type A operations, such genes constitute an essential feature of the vector without, under any conditions or circumstances, resulting in a harmful or pathogenic phenotype of the genetically modified micro-organism.

The vector should be limited in size as much as possible to the genetic sequences required to perform the intended function.

The vector should not increase the stability of the genetically modified micro-organism in the environment (unless that is a requirement of the intended function).

The vector should be poorly mobilisable

It should not transfer any resistance markers to micro-organisms not known to acquire them naturally (if such acquisition could compromise use of drugs to control disease agents).