Genome regulatory elements: CCMB finding helps in gene therapy and making transgenic animals and plants effective
Syed Akbar Hyderabad: Scientists at the city-based Centre for Cellular and MolecularBiology have found genome regulatory elements that can help in effective and successfulintroduction of genes from external sources into an organism. These regulatory elementsare conserved during evolution and form part of the mechanism involving gene therapy andmaking transgenic animals and plants. Gene therapy, which is likely to emerge as a major frontier of medical science in nearfuture, has its drawbacks too. But the findings of the CCMB team headed by Dr Rakesh KMishra may help in overcoming these drawbacks to make gene therapy really reliable intreating genetic diseases, for which there's no cure at present. There are a number ofdiseases for which gene therapy is the only hope. In gene therapy, defective genes are corrected by introducing functional genes in thepatient body. In many cases though the gene therapy solves the identified problem, itleads to emergence of new health issues. Some times this is because the genomic contextin which new gene is inserted leads to inappropriate interactions of the genetic materialin the vicinity. The CCMB team has noticed that there exists "boundary elements", which divide the genomicinformation into different compartments so as to avoid unwanted disturbance or cross-talk. Thanks to these boundary elements, even if a new gene is inserted to replace a defectivegene, the genetic information in the region does not get troubled. This mechanism worksacross the species in plants and animals, ranging from the simple Drosophila to thecomplex human beings. "Our finding has significant advantage to gene therapy and development of transgenicplants and animals. In gene therapy it will protect the gene which we insert from beingmis-regulated. It will also help in making transgenic plants and animals more regulatedby reducing undesired features, which crop up due to accidental misregulation. Whateveryou want to make will be more effective and less disturbed," said Dr Rakesh Mishra. Dr Mishra's team followed "Hox genes" that determine which part of the fertilised eggmass to develop into which body part. They help in providing proper shape to the body,whether insect or mammal, including formation of the organs and positioning them in order. "In vertebrates, distinctly expressed Hox genes are closely spaced. This raises thepossibility of boundary elements being present in the intergenic locations to mark theregulatory features of each gene, in a manner similar to Drosophila homeotic generegulation. The Evx2-Hoxd13 region in the mouse HoxD complex is one such example wheretwo differentially expressed genes are separated by about 9 kb of intervening DNA, headded. These findings have been published in the prestigious international journal‘Development’ recently.