Advances in equine cloning by somatic cell nuclear transfer (SCNT) technique in horses: a review

Abstract

Cloning a horse means using the genetic material (DNA) from a donor horse to produce a genetically identical foal. This technique involves collecting the DNA from the donor and inserting that DNA into an egg from another mare whose, DNA content has been removed, fusing donor nucleus with enucleated recipient oocytes, which then develops as an embryo, in vitro culture of embryo and lastly transfer cultured embryo into the uterus of a recipient mare. The modification of the in vitro culture conditions which can be suitable for equine oocyte activation, oocyte maturation and embryo development are the fundamental steps for a successful in vitro procedure for somatic cell nuclear transfer (SCNT) in the horse to avoid the embryo losses. In general, few studies are available in the literature on equine in vitro embryo production and it is only recently that reports have been published on completely in vitro production of equine preimplantation embryos by means of in vitro oocyte maturation. The present review discusses the latest developments in the field of equine cloning technique with the employment of SCNT. The basic understanding of SCNT for in vitro culture conditions is relevant to the increased efficiency of cloning. The available genotype can be used by SCNT which can enhance the vigour of a particular infertile or low fertile animal to produce normal fertility.

Use of mitochondrial sequencing to detect gene doping in horses via gene editing and somatic cell nuclear transfer

“…recently reviewed by Zhao et al 9 and the use of embryos in Navarro-Serna et al 10 To circumvent the potential mosaicism issues of direct injection of reagents into embryos, gene editing in large animals often combines CRISPR/Cas9 with techniques used in animal cloning. Cloning animals has been successfully achieved in many different species, 11 including horses [12][13][14] and, more recently, monkeys. 15 Cloning typically makes use of somatic cell nuclear transfer (SCNT), 16 in which the nucleus of a cultured cell is transferred into a enucleated recipient oocyte.…”