'Designer Sperm' Inserts Custom Genes into Future Generations

Scientists have taken a giant leap forward when it comes to genetics. They've created "designer sperm" that can introduce new, functioning genes into future generations, changing faulty genes that could result in certain diseases. The findings could be huge for treating heritable disorders in children.

"Transgenic technology is a most important tool for researching all kinds of diseases in humans and animals, and for understanding crucial problems in biology," said Anil Chandrashekran, one of the researchers, in a news release.

In this case, the scientists used mice. More specifically, they employed lentiviruses to generate transgenic animals via the male germ line. When pseudotyped lintiviral vectors encoding green fluorescent protein (GFP) were incubated with mouse spermatozoa, these sperm were highly successful in producing transgenics. Lentivirally-transduced mouse spermatozoa were then used in in vitro fertilization studies. When followed by embryo transfer, at least 42 percent of founders were transgenic for GFP. In fact, GFP expression was detected in a wide range of murine tissues, including testis, and the transgene was stably transmitted to a third generation of transgenic animals.

What does this mean exactly? Scientists managed to introduce new genetic material via a viral vector into the sperm of mice. This led to the presence and activity of those genes in the resulting embryos. This could mean that in the future, researchers may be able to introduce functioning genetic material to replace non-functioning genes.

"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," said Gerald Weissmann, Editor-in-Chief of The FASEB Journal, in a news release. "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. If we are able to alter sperm to improve the health of future generations, it would completely change our notions of 'preventative medicine.'"

The findings are published in The FASEB Journal.