We examined the effects of fertilization and gypsy moth defoliation of hybrid poplar (Populus ×canadensis Moench ‘Eugenei’) on ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) fungal colonization, ECM richness, and ECM composition in the summers of 1997 and 1998. The factorial experiment included two levels of defoliation (defoliated and control) and fertilization (100 kg N·ha–1 and contro...

BACKGROUND Failed fertilization post-ICSI has been mainly attributed to the sperm's inability to induce oocyte activation. Phospholipase C zeta (PLCζ) is considered to be one of the factors for the induction of oocyte activation. The aim of this study was to quantitatively assess the expression of PLCζ in globozoospermic men or those with previously low or failed fertilization in comparison wit...

Flavonoids are thought to function in the plant stress response and male fertility in some, but not all, species. We examined the effects of a self-fertile chalcone synthase null allele, a, for the effects of heat and light stress on fertilization success and flower production in Ipomoea purpurea. Pollen recipients and pollen donors of both homozygous genotypes exhibit reduced fertilization suc...

Intracytoplasmic sperm injection (ICSI) is the latest, and by far the most efficient, variant of micromanipulation-assisted fertilization, whereby a single spermatozoon is selected, aspirated into a microinjection needle and injected to the oocyte cytoplasm. The development of this technique is mainly linked to application in human assisted reproduction for which it enables fertilization with d...

We examined the effects of mitomycin C and aminopterin on ovulation in vivo and, fertilization, subsequent cleavage and implantation in slc-ICR female mice using methods of fertilization and culture in vitro. Chemicals were injected into mice at the MI (meiosis I) stage or 3 hours before the MI stage in order to examine their toxicity. Mitomycin C did not affect ovulation, but decreased the rat...

In species where males express carotenoid-based sexual signals, more intensely coloured males may be signalling their enhanced ability to combat oxidative stress. This may include mitigating deleterious oxidative damage to their sperm, and so be directly related to their functional fertility. Using a split-clutch in vitro fertilization technique and dietary carotenoid manipulation, we demonstra...

Fertilization of the sea urchin egg triggers a sequence of events that are necessary for metabolic derepression and stimulation of proliferation. Changes in intracellular Ca2+ and H+ activities regulate the sequence of events. Intracellular sodium activity is important in the regulation of the intracellular activities of these ions and may directly regulate metabolic events. Using Na+-sensitive...

Many studies on selective fertilization in maize, Zea mays L., have been reported since it was detected that genetic factor (s) linked to the de gene is responsible for distortion of segregation in F 2.2> On the other hand, some applications of the selective fertilization to maize breeding, i.e. prediction for combining abi lity of inbred lines or F1 seed production without using cytoplasmic ma...

Background: Techniques of sperm preparation require centrifugation to separate spermatozoa from the seminal plasma. The centrifugation can induce damage to the spermatozoa and increase reactive oxygen species(ROS) productionspecially in leukospermic speciemens that are associated with impaired function and fertilizing capacity. However in ICSI, fertilization can occure with damage DNA sperm but...

sperm chromatin integrity has been being recognized as an important factor in male fertility. during normal fertilization, high quality sperm with intact chromatin are selected through natural selection in journey from vagina to fallopian tube. however, using assisted reproductive techniques, particularly icsi, the natural selection is bypassed. therefore sperm with dna breakage have the opport...