A team of US scientists has created viable monkey sperm in mice, using transplanted testicular tissue.* From the date of the transplant, it took seven months for live sperm to be produced.
Amusing as the image of a mouse with monkey balls on its back is, the research is being done for a purpose, not just the entertainment of the faculty staff. The technique will initially be used to reduce the amount of experimentation on primates, but could be used to help conserve endangered animal populations. Researchers also say that it is possible that human sperm could be grown in the same way – a novel, if controversial, approach to human fertility treatment.
The testis skin from a young rhesus macaque monkey was implanted under the skin on the back of a mouse with a depleted immune system. This minimised the likelihood that the tissue would be rejected. The mouse was also castrated, so that it would produce a higher level of the hormone that switches on sperm production. This causes the transplanted skin to grow faster.
The next step, say researchers, is a trial with domestic cats as a prelude to work with big cats that only rarely survive to reproductive age in captivity.
Not content with shouldering baby-monkey balls, hard-working research mice have also made contributions to our understanding of heart health, memory and smell this week.
Genetic engineers have inserted a gene into mice that enables them to produce omega-3 fatty acids. These are the acids associated with good heart heath, and are most readily available in fish. The researchers want to see if they can accomplish the same with farm animals, so that meat and dairy produce could “grow their own” Omega-3. However, the team at Harvard acknowledges that the public is still a touch sceptical about genetically modified food, especially in Europe.
In New York, meanwhile, mice have helped in the development of a treatment for age-related memory loss. According to Nobel prize-winner Dr. Eric Kandel the drug, Mem 1003, works by preventing calcium building up in brain cells and makes the cells more responsive to incoming signals. "If you are a mouse, we can handle your age-related memory loss," he said. The drug is now in the first stages of human trials.
Finally, a missing protein could be the answer to the centuries old riddle of why some people think wine smells of strawberries and cabbages, while others can smell only grape. Mice without a protein called Kv1.3, a molecule used in nerve communication, were able to track down hidden food in half the time of those with the protein. Debi Fadool from Florida State University in Tallahassee and her colleagues found that the genetically altered mice were able to detect smell 1000 weaker than their au-naturelle cousins. ®
*Try saying that, quickly, after a couple of beers