Abstract
Somatic cell nuclear transfer (SCNT) has been an area of interest in the field of stem cell research and regenerative medicine for the past 20 years. The main biological goal of SCNT is to reverse the differentiated state of a somatic cell, for the purpose of creating blastocysts from which embryonic stem cells (ESCs) can be derived for therapeutic cloning, or for the purpose of reproductive cloning. However, the consensus is that the low efficiency in creating normal viable offspring in animals by SCNT (1–5%) and the high number of abnormalities seen in these cloned animals is due to epigenetic reprogramming failure. In this review we provide an overview of the current literature on SCNT, focusing on protocol development, which includes early SCNT protocol deficiencies and optimizations along with donor cell type and cell cycle synchrony; epigenetic reprogramming in SCNT; current protocol optimizations such as nuclear reprogramming strategies that can be applied to improve epigenetic reprogramming by SCNT; applications of SCNT; the ethical and legal implications of SCNT in humans; and specific lessons learned for establishing an optimized SCNT protocol using a mouse model.
Highlights
Somatic cell nuclear transfer (SCNT) has been an area of interest in the field of stem cell research and regenerative medicine for the past 20 years
The results suggest that cumulus cell DNA may be reprogrammed more effectively after SCNT
The derivation of human embryonic stem cells (ESCs) has been achieved at high rates from SCNT-produced blastocysts, which is critical to the potential use of SCNT as a method for therapeutic cloning [35,37,129]
Summary
Somatic cell nuclear transfer (SCNT) has been an area of interest in the field of stem cell research and regenerative medicine for the past 20 years. TTrraannssffeerrrriinngg aanndd ffuussiioonn ooff tthhee ddoonnoorr ssoommaattiicc cceellll nnuucclleeuuss ttoo tthhee ccyyttooppllaasstt iiss aannootthheerr ppoossssiibbllee ddeettrriimmeennttaall sstteepp. AAnnaaddjjuussttmmeenntt wwaass mmaaddee ttoo bbyyppaassss tthhee aaddvveerrssee eeffffeecctt ooff pprreemmaattuurree aaccttiivvaattiioonn ccaauusseedd bbyy eelleeccttrrooffuussiioonn tthhrroouugghh tteessttiinngg aa mmeemmbbrraannee ffuussiioonn aapppprrooaacchh uussiinngg aann iinnaaccttiivvaatteedd SSeennddaaii vviirruuss,, aallssoo kknnoowwnn aass hheemmaagggglluuttiinnaattiinngg vviirruuss ooff JJaappaann ((HHVVJJ)) eexxttrraacctt,, bbeettwweeeenn tthhee ddoonnoorr ssoommaattiicc cceellll aanndd tthhee ccyyttooppllaasstt [[6644]]. A study in which monkey oocytes were exposed to caffeine, a protein phosphatase inhibitor, reported effective protection of the cytoplast from premature activation, as well as improved development of SCNT embryos [65]. Itnht.aJt. iMsorl.eSqcui.i2r0e2d0,f2o1r, 2s3u1c4cessful reprogramming [32] Another downfall of the SCNT protocol yet to be corrected is the cell-cycle stage incompatibility between the donor somatic cell nucleus and the cytoplast, which may cause irregular DNA replication and aneuploidies [66]. As an additional activation stimulant and not as a cell fusion promoter, an electric pulse has previously been used to support efficient activation and reprogramming of the cytoplast after human SCNT [35]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
