Retraction

After publication of article [1], we became aware of the fact that Figures one C (let-7a and let-7a#), four B (bmo-let-7a and bmo-let-7a#) and five B (let-7a and let-7a#) were duplicated from another published article [2]. In light of these problems, the authors in consultation with the journal's Editors, have decided to retract article [1] from BMC Genomics. The authors are currently preparing a new manuscript clarifying the role of let-7a during the life cycle of the silkworm.