Contents

Restriction Enzymes

Restriction enzymes are one of the most important tools in the recombinant DNA technology toolbox. But how were these enzymes discovered? And what makes them so useful?

The Biotechnology Revolution: PCR and the Use of Reverse Transcriptase to Clone Expressed Genes

Gene cloning and PCR allow scientists to make a large amount of DNA from only a small fragment. How do these technologies work?

Quantitative Genetics: Growing Transgenic Tomatoes

How would you build a "better" tomato? Most likely, you'd select for genes in multiple locations—or quantitative trait loci (QTLs). Knowledge of QTLs is extremely valuable to crop scientists.

Recombinant DNA Technology and Transgenic Animals

GloFish are the first transgenic animals available to the American public. But what's the biotechnology behind them?

Gene Therapy

Can you stop LCA, a form of blindness caused by a change in a single base pair, simply by injecting a viral vector with the right nucleotide sequence? Unfortunately, gene therapy is not this simple.

Gene therapy restores vision in a canine model of childhood blindness

The relationship between the neurosensory photoreceptors and the adjacent retinal pigment epithelium (RPE) controls not only normal retinal function, but also the pathogenesis of hereditary retinal degenerations. The molecular bases for both primary photoreceptor and RPE diseases that cause blindness have been identified. Gene therapy has been used successfully to slow degeneration in rodent models of primary photoreceptor diseases, but efficacy of gene therapy directed at photoreceptors and RPE in a large-animal model of human disease has not been reported. Here we study one of the most clinically severe retinal degenerations, Leber congenital amaurosis (LCA). LCA causes near total blindness in infancy and can result from mutations in RPE65 (LCA, type II; MIM 180069 and 204100). A naturally occurring animal model, the RPE65 -/- dog, suffers from early and severe visual impairment similar to that seen in human LCA. We used a recombinant adeno-associated virus (AAV) carrying wild-type RPE65 (AAV-RPE65) to test the efficacy of gene therapy in this model. Our results indicate that visual function was restored in this large animal model of childhood blindness.

Genetic Inequality: Human Genetic Engineering

As genetics allows us to turn the tide on human disease, it's also granting the power to engineer desirable traits into humans. What limits should we create as this technology develops?

Sports, Gene Doping, and WADA

Gene doping could stretch the physical limits of human strength and endurance. What are the consequences of gene therapy in sports competition, and more, importantly, is it safe?