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,...

In the present work, we analyzed the structure of oocytes and fertilized eggs of the piracanjuba fish (Brycon orbignyanus) under light and scanning electron microscopy. After inducing spawning, samples were collected at the moment of oocyte extrusion, when oocytes and semen were mixed (time 0), as well as at 10, 20 and 30 s after mixing, every minute up to 10 min, and then at 15 and 20 min. The...

Study of living frog oocytes with the phase microscope has shown that the early yolk appears in two forms. One of these, the protein yolk, consists of thin, dense, plate-like bodies which in face view are almost always regular hexagons. The other form, the fatty yolk, occurs as clusters of globules of varying sizes. The plate-like bodies occur both singly and in clusters. As the oocytes mature ...

In horses, successful in vitro fertilization procedures are limited by our inability to consistently mature equine oocytes by in vitro methods. Growth hormone (GH) is an important regulator of female reproduction in mammals, playing an important role in ovarian function, follicular growth and steroidogenesis. The objectives of this research were to investigate: the effects of equine growth horm...

Developing oocytes of the cnidarian Bunodosoma cavernata are located within the mesoglea of the mesenteries of the gastrovascular cavity. The cortex of the more mature vitellogenic oocytes contains numerous, electron-dense, membrane-bound, cortical granules. The surface of these oocytes possesses prominent radially projecting structures termed cytospines. Each cytospine has a core of microfilam...

Attempts on artificial maturation of European eel (Anguilla anguilla) have largely been unsuccessful. The moment of stimulation of final maturation and ovulation is mainly based on weight increase related to the hydration response of the oocytes, which, in the European eel, is irregular. In contrast to Japanese eel, European eels show wide individual variability and much slower response to horm...

BACKGROUND Growing cells in simulated weightlessness condition might be a highly promising new technique to maintain or generate tissue constructs in a scaffold-free manner. There is limited evidence that microgravity condition may affect development of ovarian follicles. The objective of the present study was to investigate the effects of simulated microgravity on the in vitro development of m...

BACKGROUND It has been reported that the progesterone receptor (PR) level is transiently increased within the follicle by LH stimulation and controls cumulus cells in follicles and oocyte maturation. The purpose of this study was to predict developmental competence of human oocytes during IVF via analysis of PR in cumulus cells surrounding mature oocytes. METHODS Prior to oocyte retrieval, th...

Xenopus postvitellogenic oocytes resume meiosis in vitro upon exposure to insulin or insulin-like growth factor 1 (IGF-1) via a ras-dependent pathway, whereas stage IV (600 micron < diameter < 1000 micron) oocytes cannot. The aim of the present study was to determine which event(s) of the transduction pathway from IGF-1 receptor to maturation-promoting factor (MPF) activation is deficient in th...

The box jellyfish Chiropsalmus quadrumanus (Chirodropida: Cubozoa: Cnidaria) is common in warm waters. Although it assumed that external fertilization a characteristic of Chirodropida, the life history C. not yet known since its reproductive behavior has never been described, nor polyp found nature. As result, absence documentation behavior, we sought to test hypothesis through histological ana...