Study: Panda immune system more resilient than previously understood

It's believed 1,600 pandas live in the wild today, down from nearly 2,500 in the 1970s. The Chinese government has set up more than 60 nature preserves to protect the remaining pandas, but conservationists say human behavior needs to change for pandas to survive. Seth Doane reports.

New research shows giant pandas have a stronger immune system than previously known, because the panda immune system develops different antigens depending on where it lives.

This genetic diversity is a natural defense against extinction, because it means a single pathogen cannot wipe out the entire population. The study shows pandas are more genetically diverse than Bengal tigers, Namibian cheetahs and other endangered species.

Pandas have been listed on the International Union for the Conservation of Nature's endangered species lists since 1990, but the new findings show that they might be more resilient to environmental change than researchers believed.

The study focused on the pandas' major histocompatibility complex (MHC). They chose this section of the genome because it is the only one that adapts to environment. Other parts of the genome remain standard across a species and are therefore not indicative of genetic diversity.

"The assumption is that a decrease in genetic variation and a lack of exchange between isolated populations increase the likelihood of extinction by reducing the population's ability to adapt to changing environments," the team wrote in the study, published Oct. 21 in the open-source journal BioMed Central.

There are currently about 1,500 giant pandas living in the wild. All 1,500 live in six mountain ranges in south-central China. Researchers at Zhejiang University in China studied the panda immune system by collecting blood, skin or fecal specimens from 218 wild pandas native to each of the six ranges.

Biologist Paul Hohenlohe, who was not involved with the study, told LiveScience that the study will help conservationists protect the panda population.

"If you need to capture 10 pandas for a captive breeding program, then you choose those 10 to encompass the most diversity," he said. "You can do that by getting them from multiple populations, or one population that has the most diversity."