[The dynamics of feed-forward loop depends on regulator type in indirect pathway].

Gene networks contain a recurring motif, called the feed-forward loop, in which a transcription factor regulates target expression directly and indirectly via the second regulator. Here we present the results of mathematical modeling of feed-forward loops with either the transcription factor or miRNA as a repressor in the indirect pathway. We showed that the substitution of the transcription factor with miRNA changes the dynamic behavior of the feed-forward loop and lends new properties critical for biological system functioning.