By analyzing the genome of various bat species, scientists found that bat DPP4 (dipeptidyl peptidase 4) genes have adapted significantly as they evolved, suggesting that the evolutionary lineage leading to Middle East Respiratory Syndrome coronavirus (MERS-CoV) may have circulated in bats for a substantial time period, according to research published in BioMed Central’s open access publication Virology Journal.

“Our analysis suggests that an evolutionary lineage leading to the current MERS-CoV co-evolved with bat hosts for an extended time period, eventually jumping species boundaries to infect humans, perhaps through an intermediate host,” said Jie Cui, lead author on the paper.

“We show that bat DPP4 genes have been subject to significant adaptive evolution, suggestive of a long-term arms-race between bats and MERS related CoVs. In particular, we identify three positively selected residues in DPP4 that directly interact with the viral surface glycoprotein,” Cui and the authors wrote.

Investigators note the need for additional research to understand the transmission route by collecting more bat MERS-CoVs.

MERS-CoV, which first appeared in Saudi Arabia during the summer of 2012, has caused 60 human deaths, according to the CDC.