Funding for this research was provided by:
National Natural Science Foundation of China (31300199)
Chinese Academy of Sciences (2014355)
Text and Data Mining valid from 2018-12-03
Received: 23 January 2018
Accepted: 17 November 2018
First Online: 3 December 2018
Compliance with ethical standards statement
: We declare that there is no conflict of interest relative to the paper.
: This work involved no human participants as subjects. Animal collection was restricted to a minimum and complied with laws.
: All authors consent with the paper and are aware of its content and organization. As the corresponding author, I am prepared to provide further documents of compliance with ethical standards upon request along the editorial process.