Retroviral vectors for gene therapy.

Although there are many hurdles to overcome for successful gene therapy, there is a vast potential to permanently incorporate genes into cells to correct genetic disorders and to combat viral infections. Retroviruses, inspite of some limitations, offer the best hope in this direction and lentiviral vectors, which infect nondividing cells, may be the choice in the future, especially in gene therapy for central nervous system disorders.

Role of heat shock transcription factors in stress response and during development.

A variety of physical and chemical stimuli were known to cause specific stress response in all organisms. Research done over the past 25 years has shown that there is a striking uniformity in the manner in which organisms respond to different forms of stress. Expression of stress responsive genes was shown to be regulated by two or more specific transcription factors present in the cell prior to stress. These specific genes were also activated during development. In this review, the role of heat shock transcription factors in stress response, during development and during cell cycle is described.

Pleiotropic effects of purine auxotrophy in Rhizobium meliloti on cell surface molecules.

Rhizobial purine auxotrophs have earlier been shown to be defective in symbiosis, though the exact reason for this failure is not clear. Using various dyes that specifically bind different cell surface molecules, we show that there are multiple changes in the cell surface molecules associated with different purine auxotrophs. Affected molecules in different purine auxotrophs that were tested include (i) acidic exopolysaccharides, (ii) cellulose fibrils, and (iii) beta (1–3) glucans. Our results show that the symbiotic deficiency of purine auxotrophs is likely to be a result of these associated changes on the cell surface.