Matchmaker, matchmaker,

Make me a match . . .

Find me a find . . .

Catch me a catch . . .

In a remote spot on the grounds of the National Zoo, in a low-rise brick office building, research scientist Jon Ballou sits with a computer full of personal data on the world’s 333 captive giant pandas.

Birth dates. Locations. Who was born in the wild. Who was born in captivity. Who begat whom. And, most important, who might be best — or worst — to have more baby pandas.

He is the panda matchmaker, if you will. He even has a “stud book,” although now it’s digital. It’s filled with tables, numbers and rankings.

Never mind the physical profiles: Heavyset. Black and white fur. Poor posture, and manners. Favorite food, bamboo.

Ballou’s interested in genes. He can tell you which pandas would be most suitable, genetically, to mate with which.

This is crucial because the zoo announced Monday that it is again trying to breed its pandas, Mei Xiang and Tian Tian, possibly for the last time.

Mei was artificially inseminated on Sunday and Monday after she and Tian Tian failed to mate on their own, the zoo said.

The two have produced only one cub, Tai Shan, in the 10 years they have been at the zoo. If no cub is forthcoming this year, China has agreed to consider replacements. China owns and leases all giant pandas in U.S. zoos.

The zoo has said it wants panda cubs in Washington and has focused intense research on panda reproduction.

The research shows that the chances of Mei becoming pregnant after years of failed attempts is low. Ballou said statistics suggest that Mei, 13, has a less than 10 percent chance.

Tian Tian, 14, has problems, too. He has proved to be a clueless breeder with flawed technique. Plus, his genes are not that valuable because his father has sired dozens of offspring in the captive population.

Ballou said both pandas ought to be replaced.

“Genetically, it would be best if we got a whole new pair,” he said. “If she can’t breed, and he’s from an overrepresented gene line, why not just start again? Get a couple of young pandas, (of) reproductive ages” and begin anew.

Short of that, Ballou said it would be best to get a new female. “If she’s not going to breed, then she’s genetically dead,” he said in an interview last week.

Ballou said his research is aimed at avoiding panda inbreeding.

“We’re trying to keep the captive population with as much genetic diversity as we can, ” he said as he sat in his office.

Inbreeding can pass along genetic mutations that could lead to potential health problems, he said. No such problems are known in the panda population so far, Ballou said, and experts would like to keep it that way.

As of last November, there were 333 in captivity around the world, mostly in China, according to a report co-authored by Ballou. Twenty-five cubs were born last year, and eight pandas died. A good target population is 500, according to the report.

Each panda gets a number and goes into the stud book.

The book also tracks where a panda has been moved over its lifetime and notes its death.

The 50 original pandas in the captive population from the wild are called “founders,” and their genes tend to be “overrepresented” in the population, Ballou said. Twenty-seven percent of the gene pool comes from only four founders, and 18 percent comes from only two.

One of them is the “infamous” founder Pan Pan, No. 308, Ballou joked. Pan Pan was captured as a cub in the mid-1980s. “He was a really good natural breeder,” Ballou said. He was bred with many different females, and “a huge proportion of the genes in the population come from him.”

The stud book is peppered with “308s” under the heading “sire.”

Pan Pan has fathered at least 32 cubs, including Tian Tian. He has sired multiple cubs a year — an amazing seven in 1997, including three sets of twins.

This was great for Pan Pan but bad for the panda gene pool.

Tian Tian, No. 458, has a less distinguished record. He has sired only the illustrious Tai Shan, who was born at the National Zoo in 2005 and lives at a panda reserve in China.

Ballou said China thus far has not consulted National Zoo officials on genetic issues or replacement pandas. But it could in the future.

“They have all the information,” he said. “We’ve been working with them now for 10, 11 years . . . so they have the tools and information they need to decide.”

But if the Chinese want to consult, Ballou said he could crank out some good genetic matches in a few minutes. “Sure,” he said. “I could do that.”

It is uncertain whether China, which has dozens of pandas in its reserves, would consent to replacements.

Last year, Chinese and U.S. officials agreed to extend the pandas’ stay in Washington for five more years. The agreement replaced a 10-year lease that expired Dec. 6, 2010. The new agreement expires Dec. 6, 2015.

According to zoo spokeswoman Pamela Baker-Masson, to open talks with China about new pandas the zoo would have to demonstrate all the work that has been done to try to produce cubs in Washington, and how it has come up short.

The zoo would then make a recommendation “for one to go back, two to go back,” she said.

Ballou said there are probably scores of female pandas that would be genetically suitable for Tian Tian.

“Then you would narrow it down by age,” he said. “Then there would be a decision: ‘Well, do we want to have a female that’s a proven breeder or not?’ That would narrow it down.”

More would depend on the institution where the panda is located.

Ballou could probably narrow it down to four or five females.