Non-additively expressed miRNAs in the maize hybrid Yuyu22 and its parental inbred lines.

Note: a + +: Extremely high parental expression, the difference of expression amounts between hybrid and high expression parental line was beyond the threshold 10%;
b+: High parental expression, the difference of expression amounts between hybrid and high expression parental line was below the threshold 10%;
c+ −: additive expression, the difference of expression amounts between hybrid and mid-parental values was below the threshold 10%;
dD: Different from additivity (mid-parent value), not belonging to any of the other classes, the difference of the expression amounts between hybrid and parental lines and the difference between hybrid and mid-parental value were both indefinable when using 10% as the threshold;
e−: Low parental expression, the difference of expression amounts between hybrid and low expression parental line was below the threshold 10%;
f− −: Extremely low parental expression, the difference of expression amounts between hybrid and low expression parental line was beyond the threshold 10%;
*: miR156k was defined both as + − and −.