Thus, follicular fluid ( FF) has been used to support in vitro maturation in different species. In most eutherian mammals, oocyte maturation naturally occurs within a growing follicle context. While IVM of horse oocytes has been studied by many researchers, donkey oocyte IVM needs further investigation. OPU has been implemented in jennies in a similar way as in mares yielding COCs recovery rates between 34 and 76%. Ovum pick up (OPU) and in vitro maturation (IVM) of cumulus-oocyte complexes (COCs) are needed for in vitro embryo production. Only a few reports have used domestic donkeys as a model for IVEP, but none achieved blastocyst development stage in vitro or pregnancies, ,, ]. Moreover, successful reports of zebra SCNT embryos and hybrids ICSI blastocyst (horse egg – zebra sperm) has been recently achieved supporting the use of IVEP for the preservation of wild equids genetics. Currently, somatic cell nuclear transfer (SCNT) and intracytoplasmic sperm injection (ICSI) are the main techniques used worldwide to produce equine embryos in vitro, , ], since conventional in vitro fertilization has been recently reported as a successful technique. Particularly, in vitro embryo production (IVEP) has gained relevance in the last few years. With a few exceptions, the horse breeding industry has allowed the implementation of assisted reproductive technologies (ARTs) to maximize reproduction efficiency and genetic preservation. Therefore, there is an urge to improve donkey conservation programs to increase the animal population, distribution, and the genetic pool among these individuals. Moreover, among domestic donkey breeds, seven out of the 28 European breeds are in a critical status, and 20 endangered. There are six extant species of donkeys including the Somali wild asses ( Equus africanus somaliensis) and Nubian wild asses ( Equus africanus africanus) considered critical endangered, and the Asiatic Wild Ass, represented by Hemiones ( Equus hemionus) and Tibetan Kiangs ( Equus kiang) considered near threatened and less concern respectively (International Union for Conservation of Nature's Red List). Presently, domestic donkeys are still employed for transportation in undeveloped countries, for meat and milk production, as companion animals, and, the jack, to produce hybrids when crossing with mares (mules). Although it is still uncertain when donkeys were domesticated, most authors underline that domestication started approximately 6000 years ago, allowing large-scale food redistribution and transportation with an essential role in the overland trade in Africa and western Asia. Interestingly, despite their phylogenetical proximity, Equus members exhibit very divergent karyotypes, genetic plasticity, and significant differences in reproductive physiology. To our knowledge, the present study is the first report of ICSI, time-lapse imaging and in vitro blastocyst production in donkey.ĭonkeys ( Equus africanus asinus) share the same genus with horses and zebras, the only extant members of the family Equidae. Our study shows that supplementing IVM media with FBS or donkey PFF supports nuclear maturation and early preimplantation embryo development after ICSI in donkeys. Donkey ICSI embryos showed similar morphokinetics to horse ICSI embryos. Although lower cumulus cells expansion was observed in oocytes of PFF group (P = 0.0010), no significant differences were described in nuclear maturation rates and preimplantation embryo development between groups. Eight OPU sessions were done in five jennies with an average recovery rate of 69.2% (n = 45 COCs). Time-lapse imagining was performed after ICSI of horse and donkey oocytes. For this, i n vitro nuclear maturation rates, cumulus cell expansion, and embryo development after ICSI of donkey COCs matured in culture media supplemented with fetal bovine serum (FBS) or donkey PFF, with a known metabolomic profile, were assessed. In this study, we tested the hypothesis that supplementation with jenny preovulatory follicular fluid (PFF) during IVM could improve oocyte developmental competence in the donkey. Yet, some donkey species and breeds are considered endangered, and these assisted-reproductive technologies could help to preserve the genetic of valuable individuals. Despite the fact that somatic cell nuclear transfer and intracytoplasmic sperm injection (ICSI) has gained relevance in the last few years in horses, few reports have been published exploring ovum pick up (OPU) and in vitro maturation (IVM) of cumulus-oocyte complexes (COCs) in donkeys. Equus members exhibit very divergent karyotype, genetic plasticity, and significant differences in their reproductive physiology.
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