Before revision:  Recent experimental studies report that an miRNA and its target mRNA reciprocally regulate each other and miRNA is recycled with a ratio upon degradation of mRNA-miRNA complex. The functionality of this mutual regulation and dynamic consequences of miRNA recycling are not fully understood.
After revision:  Recent experimental studies report that an miRNA and its target mRNA reciprocally regulate each other and miRNA is recycled with a ratio upon degradation of mRNA-miRNA mutual regulation to bistability is not fully understood.