While kangaroos and koalas are better known, when researchers study marsupials, they often use opos ums in lab experiments because they are smaller and easier to care for. The gray short-tailed opus, MS, the species used in the study, belongs to the white-faced North American oss foss sums, but it is small and not a pouch.

Researchers at Ricken used CRISPR to delete or harden the gene that codes for pigment production. Targeting this gene means that if the experiments work, the result will be clear at a glance: if both copies of the gene are cocked, and the same ledge is deleted, the moplack or mosaic will be opus umsm albino.

The resulting waste includes an albino oposum and a mosaic oposum (pictured above). The researchers also bred both, resulting in a complete waste of albino oposomes, showing that color is a hereditary genetic trait.

Researchers had to explore some obstacles to edit the oss posom genome. First, they had to work on the timing of hormone injections to prepare the animals for pregnancy. Another challenge was that the marsupial eggs develop a thick layer around them, called the mucoid shell immediately after fertilization. This makes it difficult to treat CRISPR in these cells. Keonari says that in their first attempt, the needle would either not penetrate the cells or damage them so that the fetus could not survive.

The researchers realized that before the coating around the egg became too hard, it would be much easier to inject in the first stage. By replacing when the lights in the laboratories were turned off, the researchers obtained oposums for post-mating in the evening so that the eggs would be ready in the morning and work later in the day.

The researchers then used a tool called a piezoelectric drill, which uses an electric charge to penetrate the membrane more easily. This helped them to inject without damaging the cells.

“I think it’s an incredible result,” says Richard Behringer, a geneticist at the University of Texas. “They have shown that it can happen. Now is the time to do biology, ”he adds.

Oposums have been used as laboratory animals since the 1970s, and researchers have been trying to modify their genes for at least 25 years, says Vandeberg, who began trying to create the first laboratory oposome colony in 1978. Genome full indexed, in 2007.

Comparative biologists hope that the ability to genetically modify oposomes will help them learn more about some of the unique aspects of martial biology that have yet to be decoded. Rob Miller, an immunologist at the University of New Mexico, who uses opus ums in the research, says, “We’ve found genes and the Marsupial genome that we don’t have, so it’s a bit of a mystery what they do.” .