Current Status of In Vitro Embryo Production in Sheep and Goats

Abstract

Contents Sheep and goat production is an important economic activity in Spain with an increasing interest in milk production. Multiovulation and Embryo Transfer (MOET) and In vitro Embryo Production (IVEP) are assisted reproductive technologies aimed at increasing the genetic diffusion of females. In vitro embryo production is a multi‐step methodology comprising the following procedures: (i) In vitro Maturation (IVM) of oocytes recovered directly from the follicles, (ii) In vitro Fertilization (IVF) or co‐incubation of capacitated spermatozoa with in vitro matured oocytes and (iii) In vitro culture (IVC) of zygotes up to the blastocyst stage. In vitro embryo production from oocytes recovered from prepubertal females is called JIVET (Juvenile in vitro Embryo Transfer) and allows shortened generation intervals and increased genetic gain. Embryo production together with embryo cryoconservation would allow large‐scale embryo marketing, a pathogen‐free genetic movement and easier and cheaper germplasm commercial transactions. Commercial Embryo activity in small ruminants is low compared to cows in the European Union (data from the European Embryo Transfer Association) and in the world (data from the International Embryo Transfer Association). There is less IVEP research in small ruminants compared to other livestock species. The aim of this review was to provide an overview of the current status of IVEP of small ruminant with an emphasis on (i) description of the main methodologies currently used for IVM, IVF and IVC of embryos (ii) comparing procedures and outputs from JIVET and IVEP of adult females and (iii) the future research perspectives of this technology.

In vitro Developmental Competence of Adult Sheep Oocytes Treated with Roscovitine

“…In this context, reproductive biotechnologies, as in vitro embryo production (IVP), represent a promising alternative to accelerate the genetic improvement and increase the productivity and profitability of livestock. However, despite this, investigations on IVP in small ruminants are still limited and the results so far obtained demonstrate that the development potential of in vitro produced embryos is still low compared to that observed in vivo or in other species (Paramio and Izquierdo 2014;Souza-Fabjan et al 2014). According to Krisher (2004), this low developmental efficiency is directly related to the poor quality of oocytes in vitro matured.…”

Transcriptome profile of one-month-old lambs’ granulosa cells after superstimulation

“…Subsequently, embryos can be generated from prepubertal lambs by follicle aspiration, in vitro maturation and in vitro fertilization [6,7]. Offspring have been successfully produced from 4- to 8-week-old lambs by embryo transfer [7,8]. This approach shortens the generation interval and accelerates the genetic gain.…”

“…However, the superstimulation treatment of lamb follicles leads to their synchronously growing to 3 to 4 mm in diameter and infrequent ovulation, following which the granulosa cells (GCs) cease dividing and stop differentiate into the specialized cells of the corpus luteum [6–8]. Furthermore, in vitro - adenosine triphosphate produced embryos derived from prepubertal oocytes show lower developmental rates [10].…”

Pronuclear formation by ICSI using chemically activated ovine oocytes and zona pellucida bound sperm

“…One hundred μL of fresh or frozen semen were added to 2 mL of TCM 199-H supplemented with 3 mg/mL BSA (BSA-TCM 199-H), and incubated for 1 h for SU to help capacitation. Afterwards, 500 μL of medium were gently removed from the top of the suspension, then 3 mL of BSA-TCM 199-H were added and centrifuged at 200 ×g for 10 min [9, 27]. The pellet was suspended to give a final concentration of 1×10 6 sperm/mL [28].…”