Before fertilization, spermatozoa must undergo a process called capacitation in order to fulfill their fertilization potential. This includes series of structural, biochemical, and functional changes before subsequent acrosome reaction fusion with the oocyte. However, low temperatures during cryopreservation may induce premature activation capacitation-like changes, also known as cryocapacitati...

Fertilization involves multiple layers of sperm-egg interactions that lead to gamete fusion and egg activation. There must be specific molecules required for these interactions. The challenge is to determine the identity of the genes encoding these molecules and how their protein products function. The nematode worm Caenorhabditis elegans has emerged as an efficient model system for gene discov...

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...

Cultural methods such as crop fertilization can affect susceptibility of plants to insect pests by altering plant tissue nutrient levels. Research shows that the ability of a crop plant to resist or tolerate insect pests and diseases is tied to optimal physical, chemical and mainly biological properties of soils. Soils with high organic matter and active soil biology generally exhibit good soil...

Assuring the highest possible quality of care to the patient is the first goal of the andrology laboratory. Quality control and quality assurance as they apply to the andrology laboratory are outlined, and special problems in quality control for sperm function assays are addressed. An example of the patient review process is presented. Quality of care also depends on the ability of the laborato...

Background: Sperm analysis is an initial detection procedure of male infertility recommended by the WHO. motility as one important parameters in sperm has a close correlation with various determinants and success Assissted Reproductive Technology (ART). Several laboratory assays were carried out complement to describe ability for fertilization. One was modified stress test (MOST) predict oocyte...

A major limitation for increasing litter size in swine is embryonic loss that occurs during the 2nd to 3rd wk of gestation. High ovulation rates of modern sows have more than supplied the potential number of embryos necessary to improve litter size. The current challenge is determining how early conceptus development affects the ability to maintain the viability through the remaining 90 d of ge...