Funding for this research was provided by:
National Natural Science Foundation of China (31672608, 31702290)
Hong Kong (GRF7201/11E)
Received: 14 July 2017
Accepted: 30 January 2018
First Online: 13 February 2018
Ethics approval and consent to participate
: The study was approved by the Animal Experimental Ethics Committee of the South China Agricultural University (approval number 2015-013).
: Not applicable.
: The authors declare that they have no competing interests.
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