53 research outputs found
Alteration of the Cortical Actin Cytoskeleton Deregulates Ca2+ Signaling, Monospermic Fertilization, and Sperm Entry
Background: When preparing for fertilization, oocytes undergo meiotic maturation during which structural changes occur in the endoplasmic reticulum (ER) that lead to a more efficient calcium response. During meiotic maturation and subsequent fertilization, the actin cytoskeleton also undergoes dramatic restructuring. We have recently observed that rearrangements of the actin cytoskeleton induced by actin-depolymerizing agents, or by actin-binding proteins, strongly modulate intracellular calcium (Ca 2+) signals during the maturation process. However, the significance of the dynamic changes in F-actin within the fertilized egg has been largely unclear. Methodology/Principal Findings: We have measured changes in intracellular Ca 2+ signals and F-actin structures during fertilization. We also report the unexpected observation that the conventional antagonist of the InsP3 receptor, heparin, hyperpolymerizes the cortical actin cytoskeleton in postmeiotic eggs. Using heparin and other pharmacological agents that either hypo- or hyperpolymerize the cortical actin, we demonstrate that nearly all aspects of the fertilization process are profoundly affected by the dynamic restructuring of the egg cortical actin cytoskeleton. Conclusions/Significance: Our findings identify important roles for subplasmalemmal actin fibers in the process of spermegg interaction and in the subsequent events related to fertilization: the generation of Ca 2+ signals, sperm penetration
Molecular techniques for pathogen identification and fungus detection in the environment
Many species of fungi can cause disease in plants, animals and humans. Accurate and robust detection and quantification of fungi is essential for diagnosis, modeling and surveillance. Also direct detection of fungi enables a deeper understanding of natural microbial communities, particularly as a great many fungi are difficult or impossible to cultivate. In the last decade, effective amplification platforms, probe development and various quantitative PCR technologies have revolutionized research on fungal detection and identification. Examples of the latest technology in fungal detection and differentiation are discussed here
The use of Loop-mediated Isothermal Amplification (LAMP) to detect the re-emerging Human African Trypanosomiasis (HAT) in the Luangwa and Zambezi valleys
Specific expression and export of the Plasmodium falciparum Gametocyte EXported Protein-5 marks the gametocyte ring stage
Purification of Co-ARIS, a Cofactor for Acrosome Reaction-Inducing Substance, from the Egg Jelly of Starfish
Correlation Between the Molecular Structure and the Biological Activity of Co-ARIS, a Cofactor for Acrosome Reaction-Inducing Substance
Acrosome Reaction-Inducing Substance Purified from the Egg Jelly Inhibits the Jelly-Induced Acrosome Reaction in Starfish: An Apparent Contradiction. (acrosome reaction/starfish sperm/egg jelly/ARIS/Co-ARIS)
Anion Channel Blockers Inhibit the Acrosome Reaction of Echinoderm Sperm. (anion channel blocker/acrosome reaction/acid release/stafish/sea urchin)
Intracellular pH Changes of Starfish Sperm Upon the Acrosome Reaction. (acrosome reaction/intracellular pH/starfish sperm/egg jelly/9-aminoacridine)
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