Biomaterial Database

A sodium-dependent, fast block to polyspermy occurs in eggs of fucoid algae. 1987

S H Brawley

Department of General Biology, Vanderbilt University, Nashville, Tennessee 37235.

More than 70% of Pelvetia fastigiata eggs and about 15% of Fucus distichus eggs become polyspermic when fertilized at natural sperm concentrations in a low-sodium (2.5 mM Na+, 450 mM N-methyl glucamine) artificial seawater. Natural levels of polyspermy are 1-3% for both species. Polyspermic eggs germinate and respond to photopolarization, but do not develop beyond an abnormal, "stumpy," four-cell stage. They die within 1-1.5 weeks. The sodium-dependent block is a fast block, and it is replaced by a second block (probably cell wall formation) no later than 9 min (Pelvetia) after eggs are shed. The sodium-dependent block in Pelvetia is very efficient; when external sodium is raised to only 47.5 mM, the level of polyspermy drops to about 25%. These results are compared with data on marine invertebrates in the context of factors such as the sperm/egg concentration at fertilization and natural, osmotic (salinity) stress.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D005260	Female		Females
D005306	Fertilization	The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.	Conception,Fertilization, Delayed,Fertilization, Polyspermic,Conceptions,Delayed Fertilization,Delayed Fertilizations,Fertilizations,Fertilizations, Delayed,Fertilizations, Polyspermic,Polyspermic Fertilization,Polyspermic Fertilizations
D000459	Phaeophyceae	A class of predominantly marine EUKARYOTA, commonly known as brown algae, having CHROMATOPHORES containing carotenoid PIGMENTS, BIOLOGICAL. ALGINATES and phlorotannins occur widely in all major orders. They are considered the most highly evolved algae because of their well-developed multicellular organization and structural complexity.	Algae, Brown,Phaeophyta,Brown Algae
D012623	Seawater	The salinated water of OCEANS AND SEAS that provides habitat for marine organisms.	Sea Water,Sea Waters,Seawaters,Water, Sea,Waters, Sea
D012964	Sodium	A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.	Sodium Ion Level,Sodium-23,Ion Level, Sodium,Level, Sodium Ion,Sodium 23
D013084	Sperm-Ovum Interactions	Interactive processes between the oocyte (OVUM) and the sperm (SPERMATOZOA) including sperm adhesion, ACROSOME REACTION, sperm penetration of the ZONA PELLUCIDA, and events leading to FERTILIZATION.	Ovum-Sperm Interactions,Sperm Penetration,Egg-Sperm Interactions,Gamete Interactions,Oocyte-Sperm Interactions,Sperm-Egg Interactions,Sperm-Egg Penetration,Sperm-Oocyte Interactions,Sperm-Oocyte Penetration,Sperm-Ovum Penetration,Sperm-Zona Pellucida Penetration,Egg Sperm Interactions,Egg-Sperm Interaction,Gamete Interaction,Oocyte Sperm Interactions,Oocyte-Sperm Interaction,Ovum Sperm Interactions,Ovum-Sperm Interaction,Sperm Egg Interactions,Sperm Egg Penetration,Sperm Oocyte Interactions,Sperm Oocyte Penetration,Sperm Ovum Interactions,Sperm Ovum Penetration,Sperm Penetrations,Sperm Zona Pellucida Penetration,Sperm-Egg Interaction,Sperm-Egg Penetrations,Sperm-Oocyte Interaction,Sperm-Oocyte Penetrations,Sperm-Ovum Interaction,Sperm-Ovum Penetrations,Sperm-Zona Pellucida Penetrations
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D056890	Eukaryota	One of the three domains of life (the others being BACTERIA and ARCHAEA), also called Eukarya. These are organisms whose cells are enclosed in membranes and possess a nucleus. They comprise almost all multicellular and many unicellular organisms, and are traditionally divided into groups (sometimes called kingdoms) including ANIMALS; PLANTS; FUNGI; and various algae and other taxa that were previously part of the old kingdom Protista.	Eukaryotes,Eucarya,Eukarya,Eukaryotas,Eukaryote