A test-tube baby [4] is the product of a successful human reproduction that results from methods beyond sexual intercourse [5] between a man and a woman and instead utilizes medical intervention that manipulates both the egg [6] and sperm [7] cells for successful fertilization [8]. The term was originally used to refer to the babies born from the earliest applications of artificial insemination...

Microscopic analyses of mammalian gamete ultrastructure have provided among the most seminal insights into fertilization. Here we present a summary of ultrastructural studies of mammalian fertilization, together with a review of the effects of post-ovulatory aging in eggs, and our own results using scanning electron microscopy to examine the effects of post-ovulatory aging on the egg membrane t...

Recombinant inbred (RI) mouse strains were developed from reciprocal crosses between two inbred strains differing in the proportion of fertilized ova (CBA, 100%; KE, 77%), to analyse the underlying factors. A correlation (r = 0.83, P < 0.01) between fertilization efficiency within 22 RI strains and after mating RI females with KE males proved that oocyte quality was involved. The following oocy...

The epididymis has an important role in the maturation of sperm for fertilization, but little is known about the epididymal molecules involved in sperm modifications during this process. We have previously described the expression pattern for an antigen in epididymal epithelial cells that reacts with the monoclonal antibody (mAb) TRA 54. Immunohistochemical and immunoblotting analyses suggest t...

For a long time, it has been assumed that the only role of sperm at fertilization is to introduce the male genome into the egg. Recently, ideas have emerged that the epigenetic state of the sperm nucleus could influence transcription in the embryo. However, conflicting reports have challenged the existence of epigenetic marks on sperm genes, and there are no functional tests supporting the role...

High levels of glucocorticoids may alter reproduction, but little is known about their direct actions on oocyte maturation, fertilization and subsequent development. Earlier work suggested negative effects of cortisol or dexamethasone on oocyte maturation but differences were noted between animal models. Both glucocorticoids reduce the p34(cdc2)-cyclin B1 complex but it is unknown if other sign...

†Background The trailing edges of species ranges are becoming a subject of increasing interest as the environment changes due to global warming. Trailing edge populations are likely to face extinction because of a decline in numbers and an inability to evolve new adaptations with sufficient speed. Discussions of character change in the trailing edge have focused on physiological, exomorphic and...

This paper postulates that in the ovary, the close association between the cumulus cells and the oocytes permits the fertilizing ability of the oocytes to be determined indirectly through cumulus cell DNA status. The objective was to use a modified comet assay to analyse cumulus cell DNA and relate the data to oocyte fertilization after intracytoplasmic sperm injection (ICSI) procedures. Oocyte...

In species with external fertilization, the guanylate cyclase family is responsible for the long-distance interaction between gametes, as its activation allows sperm chemotaxis toward egg-derived substances, gamete encounter, and fertilization. In species with internal fertilization, guanylate cyclase-activating substances, which are secreted by several tissues in the genital tracts of both sex...

To determine the optimum culture duration for porcine growing oocytes (GOs) to attain maturation competence, we examined the meiotic competence, chromatin configuration, and fertilization ability of porcine oocytes obtained from early antral follicles and cultured for 10-16 days. The survival rate of oocytes after 10 days of culture (62.8%) was similar to that of oocytes after 12 days of cultur...