Handmade cloning: recent advances, potential and pitfalls

Abstract

Handmade cloning (HMC) is the most awaited, simple and micromanipulator-free version of somatic cell nuclear transfer (SCNT). The requirement of expensive micromanipulators and skilled expertise is eliminated in this technique, proving it as a major revolution in the field of embryology. During the past years, many modifications have been incorporated in this technique to boost its efficiency. This alternative approach to micromanipulator based traditional cloning (TC) works wonder in generating comparable or even higher birth rates in addition to declining costs drastically and enabling cryopreservation. This technique is not only applicable to intraspecies nuclear transfer but also to interspecies nuclear transfer (iSCNT) thus permitting conservation of endangered species. It also offers unique possibilities for automation of SCNT which aims at production of transgenic animals that can cure certain human diseases by producing therapeutics hence, providing a healthier future for the wellbeing of humans. The present review aims at highlighting certain aspects of HMC including recent advancements in procedure and factors involved in elevating its efficiency besides covering the potentials and pitfalls of this technique.

The potential and pitfalls of de‐extinction

“…At face value, such attempts seem promising – this approach has been successfully applied to extant mammals (Verma et al . ). Although most notably first used in 1996 to give rise to ‘Dolly’ the sheep, who was produced from a mammary cell nucleus inserted into an enucleated sheep oocyte (Wilmut et al .…”

“…), to date successes span a wide taxonomic diversity, including five orders and 13 genera (Verma et al . ). Furthermore, only a few years after the birth of Dolly we saw the first live mammalian offspring produced by interspecies somatic cell nuclear transfer (iSCNT), in the form of an endangered gaur ( Bos gaurus ) birthed from a Bos taurus mother (Lanza et al .…”

“…However, due to the natural limits of available suitable starting material, cloning for de-extinction would likely require the use of somatic cell nuclear transfer (SCNT) using cells taken from a fully developed animal. At face value, such attempts seem promisingthis approach has been successfully applied to extant mammals (Verma et al 2015). Although most notably first used in 1996 to give rise to 'Dolly' the sheep, who was produced from a mammary cell nucleus inserted into an enucleated sheep oocyte (Wilmut et al 1997), to date successes span a wide taxonomic diversity, including five orders and 13 genera (Verma et al 2015).…”

“…At face value, such attempts seem promisingthis approach has been successfully applied to extant mammals (Verma et al 2015). Although most notably first used in 1996 to give rise to 'Dolly' the sheep, who was produced from a mammary cell nucleus inserted into an enucleated sheep oocyte (Wilmut et al 1997), to date successes span a wide taxonomic diversity, including five orders and 13 genera (Verma et al 2015). Furthermore, only a few years after the birth of Dolly we saw the first live mammalian offspring produced by interspecies somatic cell nuclear transfer (iSCNT), in the form of an endangered gaur (Bos gaurus) birthed from a Bos taurus mother (Lanza et al 2000).…”

Pathways to de‐extinction: how close can we get to resurrection of an extinct species?

“…Since the successful cloning of Dolly the sheep in the mid-1990s (Wilmut et al 1997), technical improvements and better understanding of cellular reprogramming have made the approach increasingly efficient (Ogura, Inoue & Wakayama 2013;Verma et al 2015). Still, while some studies report high success rates, on average, <5% of potential clones develop into live offspring (Whitworth & Prather 2010).…”