Gene deletion

This example of antibody catalysis illustrates the ability of abzymes to implant cell viability in the face of a damaged or deleted gene for an essential metabolic process. The medical opportunities for applications of such catalysis are clear. 

Gene deletion Gene conversions Loss of function ... 

Retinoblastoma is a childhood cancer of the developping retina. The deleted gene, responsible for the disease encodes a protein, pRB, which is like a tumoursuppressor. It interacts with various transcription factors and suppresses cellular proliferation. 

Fig. 6. A field of T7 heads obtained from a cryoelectron micrograph of a complete tail-deletion (genes 11 and 12) mutant. Empty capsids appear as thin-walled particles. Full capsids exhibit the characteristic 2.5-nm spacing of densely packed DNA duplexes in motifs that vary according to viewing direction. The concentric ring motif is discemable in the views along the axis that passes through the connector-core vertex that is in the center of the particle.

Four 8 chain variants have been described in which deletions of amino acid residues are present (Table 6) these abnormal j3 chains are the product of a structural p chain gene with loss of one or more than one base triplet (internal deletion gene). 

Roach A, Takahashi N, PravtchevaD, Ruddle F, Hood L 1985 Chromosomal mapping of mouse myelin basic protein gene and structure and transcription of the partially deleted gene in shiverer mutant mice. Cell 42 149-155... 

One remaining problem with tissue-specific null mutants that exploit the Cre/ lox-P system is that early excision at the time of birth of sensory neurons may allow developmental compensatory mechanisms to occur, again complicating phenotypic analysis, particularly in terms of behaviour. It would thus be ideal to be able to delete genes in adult animals, whose behaviour under control conditions has already been assessed. Recent advances in gene dehvery suggest that this approach may be feasible. 

Wolfle, W.T., Washington, M.T., Prakash, L., and Prakash, S. (2003) Human DNA polymerase K uses template-primer misalignment as a novel means for extending mispaired termini and for generating single-base deletions. Genes Dev., 17, 2191-2199. 

---