Effects of ovary storage temperature and embryo vitrification on somatic cell nuclear transfer outcomes in goats

Abstract

Improving the genetic potential of farm animals is one of the primary aims in the field of assisted reproduction. In this regard, somatic cell nuclear transfer (SCNT) can be used to produce a large number of embryos from genetically elite animals. The aims of the present study were to assess the effects of: (1) ovary storage conditions on preimplantation development of recovered oocytes and the freezability of the derived blastocysts; and (2) vitrification of goat SCNT-derived blastocysts on postimplantation development. Goat oocytes were recovered from ovaries and stored under warm (25°C-27°C) or cold (11°C-12°C) conditions before being used to produce SCNT embryos. There were no differences in oocytes recovered from ovaries kept under cold versus warm storage conditions in terms of cleavage (mean (±s.d.) 95.68±1.67% vs 95.91±2.93% respectively) and blastocyst formation (10.69±1.17% vs 10.94±0.9% respectively) rates. The re-expansion rate of vitrified blastocysts was significantly lower for cold- than warm-stored ovaries (66.3±8.7% vs 90±11% respectively). To assess the effects of vitrification on postimplantation development, blastocysts from cold-stored ovaries only were transferred from fresh and vitrified–warmed groups. The pregnancy rate was comparable between the fresh and vitrified–warmed groups (41.65% and 45.45% respectively). In addition, established pregnancy in Day 28-38 and full-term pregnancy rates were similar between the two groups. In conclusion, this study shows similar invitro preimplantation developmental potential of warm- and cold-stored ovaries. This study introduces the vitrification technique as an appropriate approach to preserve embryos produced by SCNT for transfer to recipient goats at a suitable time.

The Impact of Two Embryo Culture Media, SOF and Commercial BO, on Pre- and Post-Implantation Development of Cloned Sannen Goat Embryos

“…The In vitro maturation (IVM) was performed as described in our previous study [26]. Brie y, the follicular content was aspirated from 2-6 mm follicles using a 20-gauge needle attached to a vacuum pump.…”

“…The establishment and progression of pregnancies in the recipient goats were measured using rectal ultrasound on days 28-38 and abdominal ultrasound on days 83-113 after embryo transfer, respectively. All the animals were allowed to undergo normal delivery [26].…”

“…The e ciency of SCNT in biotechnology [20], biomedicine, stem cells [24], transgenic animal production [25], conservation of endangered species, and breeding has attracted considerable attention in recent years [26]. However, despite the signi cant improvements made to enhance the reprogramming e ciency of SCNT, the technical e ciency and high throughput of SCNT has limited its application and reduced its success rate compared to IVF [27][28][29].…”

Controlled Cytoplast Arrest and Morula Aggregation Enhance Development, Cryoresilience, andIn VivoSurvival of Cloned Sheep Embryos

“…Vitrification eases the logistical constraints for generating offspring since recipient ewes do not need to be concurrently synchronized when producing embryos. Vitrification was successfully used for sheep cloning in one study (Peura et al, 2003) and recently in goats (Hajian et al, 2020), but overall, there are few reports on its effect on embryo survival for cloned sheep embryos.…”

The Overexpression of Tβ4 in the Hair Follicle Tissue of Alpas Cashmere Goats Increases Cashmere Yield and Promotes Hair Follicle Development

“…In addition to traditional breeding methods, more efficient transgenic technologies have recently become widely used to generate transgenic animals. Somatic cell nuclear transfer (SCNT) can be used to produce a large number of embryos from genetically elite animals [25,26]. Reproductive cloning by SCNT using genetically-modified donor cells is a valuable method to propagate animals with desirable traits [9,10,27,28].…”