The once futuristic possibility of custom-making “designer” organs may have moved one step closer to reality, as British and American scientists successfully inserted new genetic material into the embryos of mice and observed the full functioning of those genes across three generations of the animals tested.
Published in The FASEB Journal, the study suggests radically unexplored frontiers may be more within reach if the current successes can be mirrored in human trials, as they could lead the way to effectively curing diseases and disorders, enable the regeneration of major organs, and allow for the complete introduction of new human attributes.
Known as transgenic technology, the process of introducing the genetic material down through a species’ germ line holds great importance for teasing out the complex relationship between biology and the environment, noted study author Dr. Anil Chandrashekran, from the Department of Veterinary Clinical Sciences at The Royal Veterinary College.
"Transgenic technology is a most important tool for researching all kinds of disease in humans and animals, and for understanding crucial problems in biology," Chandrashekran said in a statement.
The study produced transgenesis – essentially introducing a new gene into a living organism so the organism produces the gene in its offspring – through the use of lentiviruses. Lentiviruses are a specific genus of viruses, including the human immunodeficiency virus (HIV) and the simian immunodeficiency virus (SIV), among others, and can be used to incubate with sperm cells (called spermatozoa). In the current study, these lentivirally-transduced sperm cells were then fertilized in vitro, and when introduced with an embryo, 42 percent of the original cases showed up transgenic for the gene being encoded.
Dr. Gerald Weissmann, Editor-in-Chief of The FASEB Journal, noted that such a finding could have massive implications for the future of human biology. "Using modified sperm to insert genetic material has the potential to be a major breakthrough not only in future research, but also in human medicine," he said. “It facilitates the development of transgenic animal models, and may lead to therapeutic benefits for people as well. For years we have chased effective gene therapies and have hit numerous speed bumps and dead ends.”
Such gene therapies don’t come without controversy. Much of the criticism surrounding notions of designer embryos is that a logical byproduct of the technology is parents conceiving their children through unnatural, customized means. Mothers and fathers will harvest individual genes in order to build composite super children that are intelligent, good looking, athletic, and won’t soon go bald.
But proponents point in another direction, one that strives to uphold the technology’s more noble pursuits. Being able to fashion a custom set of genes could mean eradication of worldwide disease, the stunting of neurological disorders like depression and Alzheimer’s, and a near total overhaul of how the currently reactionary body of medical science treats its patients.
“If we are able to able to alter sperm to improve the health of future generations,” Weissmann said, “it would completely change our notions of 'preventative medicine.'"
Source: Chandrashekran A, Sarkar R, Thrasher A. Efficient generation of transgenic mice by lentivirus-mediated modification of spermatozoa. The FASEB Journal. 2013.