Electroporation preceding in vitro fertilization of in vitro matured oocytes: implications for bovine embryo development.

Edição dos resumos da 37ª Annual Meeting of the Brazilian Embryo Technology Society

Toward in vitro fertilization in Brachiaria spp.

Brachiaria are forage grasses widely cultivated in tropical areas. In vitro pollination was applied to accessions of Brachiaria spp. by placing pollen of non-dehiscent anthers on a solid medium near isolated ovaries. Viability and in vitro germination were tested in order to establish good conditions for pollen development. Comparing sexual to apomictic plants, apomictic pollen has more abortion after meiosis during the microspore stage and a lower viability and, of both types, only some plants have sufficient germination in a high sugar concentration. Using in vitro pollination with the sexual plant, the pollen tube penetrates into the nucellus and micropyle, but the embryo sac degenerates and collapses. In the apomictic B. decumbens, in vitro pollination leads to the transfer of the sperm nuclei into the egg cell and the central cell. The results are discussed according to normal fertilization and barriers in sexual and apomictic plants

Involvement of sperm acetylated histones and the nuclear isoform of Glutathione peroxidase 4 in fertilization

We previously demonstrated that the nuclear form of Glutathione peroxidase 4 (nGPx4) has a peculiar distribution in sperm head, being localized to nuclear matrix and acrosome and that sperm lacking nGPx4 are more prone to decondensation in vitro. In this study we have hypothesized that sperm retained acetylated histones and nGPx4 are implicated in paternal chromatin decondensation and male pronucleus formation at fertilization. Indeed, significant higher amounts of acetylated histone H4 and acetylated histone H3 were observed by both immunofluorescence and western blotting in nGPx4-KO sperm vs WT ones. In vitro fertilization of zona pellucida- deprived oocytes by WT sperm in the presence of trichostatin (TSA) also demonstrated that paternal histone acetylation was inversely related to the timing of sperm nucleus decondensation at fertilization. In contrast, TSA had no effect on nGPx4-KO sperm, indicating they had a maximal level of histone acetylation. Moreover the paternally imprinted gene Igf2/H19 was hypomethylated in KO sperm compared to WT ones. The lack of nGPx4 negatively affected male fertility, causing a marked decrease in total pups and pregnancies with delivery, a significant reduction in pronuclei (PN) embryos in in vitro fertilization assays and an approximately 2 h delay in egg fertilization in vivo. Because the zona pellucida binding and fusion to oolemma of nGPx4-KO and WT sperm were similar, the subfertility of nGPx4 sperm reflected a decreased sperm progression through egg cumulus/zona pellucida, pinpointing a defective acrosome in line with acrosomal nGPx4 localization. We conclude that paternal acetylated histones and acrosomal nGPx4 are directly involved in fertilization

In Vitro Fertilization

The field of In Vitro Fertilization is a relatively new field in medicine, constantly on the move. This field is an exquisite example of the vast power in the complementary use of basic research with clinical practice and opened a new route of great basic and clinical research possibilities. The knowledge base that allowed the accomplishment of the idea of in vitro fertilization and embryo transfer has much developed since. The vast body of research pertaining to this field allowed deepening our understanding in the processes related to reproduction. In this book on in vitro fertilization we present new and interesting updated information in various aspects of this field. This work is a result of collaborative work of an international group of professionals dedicated to contribute to the advancement of our knowledge

Ethics and Uncertainty: In Vitro Fertilization and Risks to Women\u27s Health

Dr. de Melo-Martin examines the risks, uncertainties and public policies surrounding in vitro fertilization and women\u27s health issues

In Vito Fertilization in Buffaloes: A Review

This is the review of original data concerning the effect of some factors on oocyte development in vitro of buffaloes. In vitro fertilization is a multi - step process: oocytes maturation, fertilization and embryo culture. In vitro fertilization is strongly influenced by events occurring during oocyte maturation, fertilization and the subsequent development of the fertilized oocytes. With the advancement of IVF procedures, variability in developmental rate and viability of in vitro produced buffalo embryos so, improving the efficiency and identifying the sources of variations between IVF systems are more important when routinely producing blastocysts from individuals of high genetic merits. Also, the development of specific culture regimes capable of supporting in vitro maturation (IVM), in vitro fertilization (IVF) and in vitro culture (IVC) to the blastocyst stage is highly desirable in breeding systems. This paper discusses the technical aspects of the procedures involved in in vitro fertilization of buffaloes

Influence of sperm-oocyte coincubation period on porcine in vitro fertilization (IVF) efficiency

A major obstacle for successful in vitro production of porcine embryos is the polyspermic fertilization. One possibility to reduce polyspermic penetration is decreasing the number of spermatozoa added to the fertilization medium. Unfortunately, the lower rate of polyspermy is accompanied by a reduced penetration rate. A short gamete coincubation period of 10 min has been described to obtain fertilization rates similar to 6 h of coincubation and may improve IVF efficiency (number of monospermic fertilized oocytes/total number inseminated) depending on sperm-oocyte ratio (Gil, 2007, Theriogenology, 67(3), 620–626). Here we demonstrate that the optimal coincubation period in our IVF conditions is between 10 min and 6 h. In vitro matured oocytes (n = 600) were inseminated with frozen-thawed epididymal semen with 600 spermatozoa per oocyte and coincubated for 2, 4 and 6 h. At 2 and 4 h post insemination (hpi), oocytes were vortexed and transferred to fertilization medium without spermatozoa. At 6 hpi, presumed zygotes of all groups were washed three times in culture medium and cultured. At 22 hpi, zygotes were fixed overnight and stained with Hoechst 33,342 for the assessment of fertilization and polyspermy. The IVF efficiency was higher for the 4 h group (40 ± 5%) than the 2 and 6 h group (19 ± 8% and 17 ± 5%). Between 4 and 6 h of gamete coincubation, the increase in the number of polyspermic oocytes was relatively higher than the increase in penetration rate (+39% vs. +15%), resulting in a decline in efficiency. (This study was supported by Research Foundation-Flanders)

Investigating the rate of different ovarian response in in vitro fertilization cycles based on estrogen receptor beta +1730 polymorphism: A cross-sectional study

Background: The response to ovarian stimulation is different among women referring for assisted reproductive techniques. This difference could be due to different genotypes in genes related to reproduction such as estrogen receptor beta (E