In Vitro Culture of Deer Embryos.

In vitro embryo production of deer species has the potential to increase valuable traits for the agricultural sector, and from a conservation perspective, it is a propagation tool which can improve genetic diversity in small captive populations. In vitro embryo production is a multistep process consisting of oocyte maturation, fertilization, and embryo culture. These techniques provide the backbone for more advanced assisted reproductive technologies such as intracytoplasmic sperm injection (ICSI), somatic cell nuclear transfer (SCNT), a source of embryonic stem cells, and embryos for gene editing. In vitro-produced embryos are a readily available resource for comparative embryology studies and a functional assay to assess oocyte competence and evaluate in vitro embryo requirements during culture. A semidefined fertilization and culture medium system, deer synthetic oviduct fluid (DSOF), has been formulated based on deer oviduct fluid. Red deer calves (Cervus elaphus) and Thamin Eld's deer fawn (Rucervus eldii thamin) have been produced after the transfer of in vitro embryos (IVF and SCNT) grown in DSOF culture. Here we describe the in vitro method of maturation, fertilization, and embryo culture for deer species.