2013: A year to clone in Japanese science

In a year when the science news in Japan is still dominated by Fukushima, there have also been plenty of inspirational stories. For this final column of 2013, I have picked a few of my favorites.

The first was quite extraordinary. Scientists at the National Institute of Genetics in Shizuoka found a way to watch thoughts moving through a brain. The fact that it was the brain of a fish makes it no less amazing. Okay, slightly less amazing. But still: A thought was physically seen!

Koichi Kawakami and colleagues genetically modified zebrafish so they produced a green fluorescent protein in their cells, but only if calcium levels reach a certain concentration. This happens in the brain when neurons fire, so by watching very young fish — whose bodies are transparent — they were literally able to see neural activity as it happened in the brain.

When they introduced a tiny prey item into the fish’s field of view, they were able to watch the neural activity corresponding to the fish tracking it. It was effectively thinking about its dinner. (Current Biology, DOI: 10.1016/j.cub.2012.12.040.)

“In the future, we will be able to interpret an animal’s behavior — including learning and memory, fear, joy or anger — based on the activity of particular combinations of neurons,” Kawakami said.

Next, in March, a cloning record was broken when 581 clones of a mouse were made by making a clone of the original mouse, then a clone of the clone, then a clone of that clone, and so on. No one had ever made so many sequential clones of an animal, but Teruhiko Wakayama of the Riken Center for Developmental Biology in Kobe succeeded where all others failed.

Cloning was the New Big Thing back in 1996, when the first cloned mammal, Dolly the sheep, was born. But by the mid-2000s the popularity of the technique had waned. A scientific fraud exposed in South Korea didn’t help, but a bigger problem was that the technique only worked on certain species. Sheep were fine, but cats proved very difficult. And for any animal, clones could only be made for a few generations before abnormalities started showing up.

Wakayama’s team solved the problem by resetting the cell each time they cloned it, making it “think” it was an embryonic cell again. When Dolly was born, her cells had a genetic age of around 6 years, the same as the “mother” sheep it was cloned from. Wakayama’s mice were not born old.

“This technique could be very useful for the large-scale production of superior-quality animals for farming or conservation purposes,” he said. Given the location of his lab, it was perhaps no surprise that he suggested a super-Kobe beef cow could be cloned. Before you even ask, he’s got no intention of trying out his technique on primates, let alone humans. (Cell Stem Cell, DOI: 10.1016/j.stem.2013.01.005.)

Cloning was big in Japan in 2013 — in mouse terms at least. In June, Atsuo Ogura, of Riken BioResource Center in Tsukuba, Ibaraki Prefecture, cloned a mouse from a single drop of blood. When Dolly was cloned, it was from a cell from the mammary gland tissue of her donor “mother.” The scientists said they named the sheep “Dolly” because they couldn’t think of a more impressive pair of mammary glands than those of the American singer Dolly Parton. Yes, they were male scientists.

Anyway, Ogura’s team figured that white blood cells could be used to provide the genetic material necessary for cloning. (Biology of Reproduction, DOI: 10.1095/biolreprod.113.110098.)

Staying with mice, there was good news this year for those with dodgy livers. In July, Hideki Taniguchi and Takanori Takebe at Yokohama City University grew tiny livers from human stem cells and transplanted them into mice. They worked as proper livers should — purifying blood.

It was the first time an organ has been grown from scratch and transplanted and shown to work correctly. The scientists say this will lead to home-grown organs for people with liver failure. (Nature, DOI: 10.1038/nature12271.)

All that mouse stuff is cool, but it’s only when things happen in humans that we tend to get really excited. And so to the Riken Center for Developmental Biology in Kobe, where the government gave the go-ahead in July for an exciting clinical trial on people. Riken, with the Institute of Biomedical Research and Innovation Hospital, will harvest stem cells from patients with an eye disease, induce the cells to grow into retinal tissue, and then transplant the tissue into the damaged eyes of the patients. This sort of trial is a world first. The eye condition is age-related macular degeneration, which affects some 700,000 people in Japan.

The health ministry has approved the trials. By mid-2014, six patients should become the first people to receive new retinal tissue grown from their own cells. Despite the intense research performed on stem cells, this is the first time cells grown from patients will be used to treat their condition.

That is certainly something to look forward to in 2014.

Rowan Hooper (@rowhoop on Twitter) is the News Editor of New Scientist magazine. The second volume of Natural Selections columns translated into Japanese is published by Shinchosha at ¥1,500. The title is “Hito wa Ima mo Shinka Shiteru (The Evolving Human).”