The primary axes of Drosophila are set up by the localization of transcripts within the oocyte. These mRNAs originate in the nurse cells, but how they move into the oocyte remains poorly understood. Here, we study the path and mechanism of movement of gurken RNA within the nurse cells and towards and through ring canals connecting them to the oocyte. gurken transcripts, but not control transcri...

Mitochondria play vital roles in oocyte functions and they are critical indicators of oocyte quality which is important for fertilization and development into viable offspring. Quality-compromised oocytes are correlated with infertility, developmental disorders, reduced blastocyst cell number and embryo loss in which mitochondrial dysfunctions play a significant role. Increasingly, women affect...

The asymmetric localization of gurken mRNA and protein in the developing Drosophila oocyte defines both the anteroposterior and dorsoventral axes of the future embryo. Understanding the origin of these asymmetries requires knowledge of the source of gurken transcripts. During oogenesis most transcripts in the oocyte are produced by the associated nurse cells, but it has been proposed that gurke...

Reproductive cessation is perhaps the earliest aging phenotype that humans experience. Similarly, reproduction of Caenorhabditis elegans ceases in mid-adulthood. Although somatic aging has been studied in both worms and humans, mechanisms regulating reproductive aging are not yet understood. Here, we show that TGF-β Sma/Mab and Insulin/IGF-1 signaling regulate C. elegans reproductive aging by m...

Some aspects of oxidative metabolism during cytoplasmic maturation of the Bufo arenarum oocyte have been studied. During the autumn-winter period (immature oocyte), carbohydrates are degraded through the glycolytic pathway, followed by the classical tricarboxylic acid cycle. During the spring--summer period (mature oocyte), carbohydrates are mainly used through the pentose phosphate cycle, whil...

Elder women suffer from low or loss of fertility because of decreasing oocyte quality as maternal aging. As energy resource, mitochondria play pivotal roles in oocyte development, determining oocyte quality. With advanced maternal age, increased dysfunctions emerge in oocyte mitochondria, which decrease oocyte quality and its developmental potential. Mitochondria supplement as a possible strate...

Since the pig is not only an important farm animal, but also a model animal for biomedical applications, the development of reproductive technologies in this species has been very important. In vitro oocyte maturation and fertilization (IVM-IVF) are basic techniques for a number of oocyte- or embryo-related technologies. The practical aspects for pig oocyte IVM-IVF have been reviewed, while the...

When a sperm and an oocyte unite upon fertilization, their cell membranes adhere and fuse, but little is known about the factors regulating sperm-oocyte adhesion. Here we explored the role of β-catenin in sperm-oocyte adhesion. Biochemical analysis revealed that E-cadherin and β-catenin formed a complex in oocytes and also in sperm. Sperm-oocyte adhesion was impaired when β-catenin-deficient oo...

Maturation and fertilization of the starfish oocyte are putative calcium-dependent events. We have investigated the spatial distribution and temporal dynamics of this calcium dependence in single oocytes of Asterias forbesi. We used the calcium photoprotein, aequorin, in conjunction with a microscope-photomultiplier and microscope-image intensifier. Surprisingly, in contrast to earlier work wit...

introduction: superovulation produces complications in some patients, so invitro maturation of oocytes is used to decrease or eliminate these complications and improve ivf. moreover, ivm is used for different aspects of reproductive researches. slaughterhouse ovaries are the main source of oocytes for ivm and ivf studies. different media has been introduced and experimented for in vitro maturat...