BACKGROUND Cryopreservation of oocytes, which is an interesting procedure to conserve female gametes, is an essential part of reproductive biotechnology. The objective of the present study was to investigate the effects of vitrification on nuclear maturation, ultrastructural changes and gene expression of canine oocytes. METHODS Immature oocytes (germinal vesicles) isolated from ovaries of no...

This report describes a live birth produced from repeat vitrification and thawing of blastocysts derived from in-vitro matured (IVM) oocytes in a woman with polycystic ovarian syndrome. Immature oocyte retrieval was performed on day 12 of her induced menstrual cycle. The patient was administered 10,000 IU of human chorionic gonadotrophin s. c. 36 h before immature oocyte retrieval. A total of 4...

BACKGROUND We assessed the maturational competence and the chromosomal pattern of mouse oocytes reconstructed by germinal vesicle (GV) transfer technique using nuclear and/or cytoplasmic components from cryopreserved GV stage oocytes. METHODS From 657 GV oocytes (326 fresh and 331 frozen/thawed), four groups of reconstructed oocytes were obtained by micromanipulation and electrofusion: fresh ...

In-vitro fertilization (IVF) relies heavily on controlled ovarian stimulation to increase the number of available oocytes and embryos, and therefore the pregnancy rate. However, the side effects, such as nausea, mood swings, menopausal symptoms, ovarian hyperstimulation syndrome (OHSS), and potential cancer risk of ovarian stimulation may not be avoided. Therefore, the recovery of immature oocy...

in vitro maturation (ivm) is a method that immature oocytes in antral follicles are extracted and matured in laboratry conditions. this review has attempted to provide the current knowledge and recent findings in in vitro maturation of oocytes and highlights the most important factors involved in this process. the review is based on literature reports and the author’s experience. in ivm cycles,...

It has been suggested that nucleus replacement (transfer) may be used as an efficient oocyte therapy in order to prevent transmission of mutated mitochondrial DNA from mother to offspring in humans. The essential and not yet answered question is how mitochondria surrounding the karyoplast will be distributed in the newly reconstructed oocytes. In our model experiments, we have evaluated the dis...

A morphological classification of the immature cumulus-oocyte complex (COC), which grossly resembled the atresia grade of its follicle source, was used in bovine oocytes to determine 1) the developmental potential by either in vitro fertilization or parthenogenetic activation, 2) the calcium current activity by whole-cell voltage clamp technique, and 3) the intracytoplasmic calcium stores by mi...

Empty follicle syndrome (EFS) is a condition in which no oocytes are obtained after an apparently successful ovarian stimulation. Genuine EFS (GEFS) is differentiated from false EFS by an optimal level of human chorionic gonadotropin on the day of oocyte retrieval. Some believe that GEFS does not exist and that it is only a reflection of the margin of error attendant upon the procedure of oocyt...