Med. Weter. 70 (1), 11-14, 2014
full text
| Młodawska W. |
| In vitro maturation and fertilization capacity of mare oocytes |
| The aim of the review was to present current views on the factors influencing the in vitro maturation (IVM) and fertilization (IVF) of mare oocytes. The first two foals produced with the use of the so-called standard IVF (co-incubation of oocytes and spermatozoa in culture media) were born over 20 years ago. To date, it has been possible to obtain offspring in horses after the fertilization of in vitro matured oocytes by the intracytoplasmic sperm injection technique (ICSI) or by the surgical transfer of oocytes to the oviducts of inseminated mares (fertilization in vivo). Causes of the low efficiency of IVF in horses are complex and may be related to an incomplete maturation of oocytes, an inappropriate method of sperm capacitation in vitro, as well as the use of non-compliant media for the development of inseminated oocytes and/or early embryos. The paper describes the method of oocyte collection from mare ovaries and the most important factors influencing the number and quality of oocytes obtained. It discusses the relationship between the physiological status of ovarian follicles, cumulus oophorus morphology and the capacity of mare oocytes for in vitro maturation and fertilization. In addition, some aspects of nuclear and cytoplasmic maturation of equine oocytes are presented. The understanding of the in vivo maturation mechanisms of equine gametes and of the developmental requirements of embryos helps to improve culture conditions and the in vitro fertilization efficiency of equine oocytes. |
| Key words: mares, oocytes, in vitro maturation, in vitro fertilization. |