“First of all,” he says, “it’s important to give credit to my co-researcher, Ximing Guo, whose name is ahead of mine on this paper. He’s a real scientific researcher; I’m just an old-fashioned bucket biologist.”

It turns out Guo, a post-graduate student from China, the aquaculture capital of the world, was at the University of Washington at the same time Allen was ramping up the chemical production of triploids on the West Coast. “We overlapped by a couple years,” Allen says. “He was always quiet and demure, but he was working away quite confidently on a way to make tetraploids.” Once Guo finished his post-doc in Seattle, Allen lured him to his lab at Rutgers and they set to work on the tetraploid.

Guo’s method was basically an elaboration on the cytochalasin approach, only he was trying to squeeze two extra sets of chromosomes into a regular diploid sperm cell. Once you created the tetraploid, you could breed that oyster with diploids to produce triploids without the use of chemicals. This is the technology behind seedless watermelon.

But it wasn’t easy. “Using these various methods, he was able to make tetraploid embryos from normal eggs, but they were never viable,” Allen said. The problem was that the nuclei of the diploid cells that Guo started with were just too small to accommodate four sets of chromosomes. Allen’s insight was to ask: “What if we started with a larger, triploid cell?”

Nature, it turns out, is full of exceptions. Even though almost all triploids are infertile, every so often you find one that actually can spawn. So, Allen and Guo and the rest of the lab began the search for fertile triploids.

Benoit Eudeline, the research director for Taylor Shellfish, one of the largest oyster hatchery operations in the country, is a former graduate student in Allen’s lab. He remembers the early days of tetraploid research.

“When I was doing my PhD., I had to open hundreds, if not thousands of oysters to find a single fertile triploid,” he says.

In the end, though, Allen’s strategy worked. A few large, fertile triploids were found, and Guo was able to work his magic on them and squeeze the two extra chromosomes into their sperm cells. And, once again, the day came when Allen and Guo were able to verify, this time with a flow cytometer instead of microscope, that they had indeed created a new oyster. The era of the tetraploid had arrived—and today’s tetraploid oysters are all derived from a those few fertile triploids Allen created over a decade ago.

This time, Allen was ready. He made sure he and Guo got the patent on the tetraploid (though, because they were university employees, the patent technically went to Rutgers). Just as important, he and Guo set up a company, aptly called 4-Cs Breeding Technology, to spread the tetraploid gospel. The idea was to license the technology to select hatcheries around the world. Those hatcheries, in turn, can use the tetraploids to produce triploids for the world’s oyster farmers. Right now, commercial hatcheries in Australia and France have the license to produce tetraploids; but the bulk of the tetraploid hatcheries are in the U.S., mostly along the East Coast and the Gulf Coast. The largest producers, though, are still on the West Coast, including the Taylor Shellfish hatchery run by Eudeline.