Author Contributions
X-L.F performed experiments and designed the study. Q.L performed the experiments. F.W and H-Y. H collect specimens. Y-D.Z, BN-JL, Z-J.Y, and X-S.L analyzed the data. X-L.F and Q.L wrote the manuscript with suggestions from other authors. All authors revised the manuscript.
Competing interests: The authors declare no competing interests.