Study on Generation of Bovine Induced Pluripotent Stem Cells Treated by piggyBac

Authentic bovine embryonic stem cells have not been established despite over two decades efforts.Recently,induced pluripotent stem cells(iPSCs) derived from somatic cells have been successfully generated from mouse,human,monkey,rat,pig,sheep,horse and cow.However,the pluripotency of large domestic animal iPS cells have not yet been tested by generation of chimera and germline transmission.Differently to virus vector,piggyback transposon was used to reprogram bovine fetal fibroblast(BFF) cells into iPS like cells.The piggyback transposon and transposase system is simple、virus-free and efficient.It just need transposase enzyme to catalyse insertion or excision events.It was reported that coexpress mouse Rarg(RAR-γ) and Lrh-1(liver receptor homologue 1) with the four factors Oct4、Sox2、Klf4 and c-Myc can obtain bovine iPS like cells.These cells exhibited typical colony morphology,like mouse ES cells.They showed normal karyotypes.Bovine iPS like cells also express ES cell markers,including Oct4、Sox2、Dnmt3b、E-cadherin、Dppa4、Stella and stage-specific embryonic antigen-4(SSEA4),TRA-1-60,TRA-1-81.The cells were able to differentiate into all three germ layers both in vitro and in teratomas.The results showed that the piggyback is an efficient tool for iPS cell derivation.