Minichromosomes: The second generation genetic engineering tool

Genetic engineering is a scientific tool used in every field of science like plant, animal and human sciences. Plant genetic engineering technology has changed the face of plant sciences and the first generation of transgenic crops has become the most rapidly adopted technology in modern agriculture. But genetic engineering has some limitations and therefore still there is a clear need of new technologies to overcome issues like gene stacking, transgene position effects and insertion-site complexity. The recent strategy that researchers have developed to overcome those limitations is the development of plant artificial minichromosomes for delivery of large DNA sequences, including large genes, multigene complexes, or even complete metabolic pathways. A minichromosome is an extremely small version of a chromosome that have been produced by de novo construction using cloned components of chromosomes or through telomere-mediated truncation of endogenous chromosomes. After a successful experiment in maize with the help of minichromsomes by J. Birchler and colleagues (Yu et al., 2007a), a new paradigm have been set for all the agricultural researchers to use the minichromosome techniques for crop improvement. Engineered minichromosomes also offer an enormous opportunity to improve crop performance, as discussed by Houben and Schubert (2007). With rapidly expanding research in minichromosome as a second generation genetic engineering tool we can hope that it will bring a new generation of improved crop species to meet the global demands.