Gametogenesis and reproductive behavior in the echinoid Lytechinus variegatus
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چکیده
منابع مشابه
Influence of sperm and phytoplankton on spawning in the echinoid Lytechinus variegatus.
The cues triggering large-scale broadcast-spawning events in marine invertebrates are not fully understood. Using the sea urchin Lytechinus variegatus, we tested the effectiveness of a variety of potential spawning cues in eliciting a spawning response. In the laboratory, during two consecutive spawning seasons, about 400 isolated sea urchins were exposed to phytoplankton, sperm, or eggs, singl...
متن کاملNuclear Membrane Fusion in Fertilized Lytechinus Variegatus Eggs
Fusion of apposed nuclear envelopes is frequently seen at telophase during postmitotic reorganization of the nucleus, but only rarely at other times in the cell cycle. We attempted to define an experimental system for studying changes in the nuclear envelope related to the cell cycle by varying the time of pronuclear apposition in fertilized Lytechinus variegatus eggs. This approach was based o...
متن کاملAcetylcholinesterase in the sea urchin Lytechinus variegatus: characterization and developmental expression in larvae.
Acetylcholinesterase (AChE) in the echinoid Lytechinus variegatus has been characterized. Kinetic parameters V(max), K(m), K(ss), and b were 2594+/-1048 nmol ATCh hydrolyzed/min/mg tissue wet weight, 185+/-11 microM, 308+/-100 mM, and 0.2, respectively for the substrate ATCh and 17.8+/-6.87 nmol BTCh hydrolyzed/min/mg tissue wet weight, 654+/-424 microM, 36+/-31 mM, and 0.6, respectively for BT...
متن کاملThe effects of dietary silver on larval growth in the echinoderm Lytechinus variegatus.
Previous studies have demonstrated that the euryhaline copepod Acartia tonsa is extremely sensitive to dietborne silver (Ag) exposure, with a 20 % inhibition (EC(20)) of survival occurring when copepods are fed algae with 1.6 μg g(-1) dry weight (dw) Ag, corresponding to a waterborne Ag concentration of 0.46 μg l(-1) Ag. In contrast, 43 μg l(-1) Ag is required to elicit similar effects in copep...
متن کاملMaking a mouth: elucidating morphogenetic events of mouth development in the sea urchin Lytechinus variegatus
Deuterostomes are bilaterian animals in which the blastopore, the site of gastrulation, becomes the anus and the mouth develops secondarily. Deuterostome phyla include Chordata, such as vertebrates like ourselves, and Echinodermata, such as sea urchins. The extent of homology among deuterostome mouths is unknown. To address this question, this thesis compares three aspects of mouth morphogenesi...
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ژورنال
عنوان ژورنال: Marine Ecology Progress Series
سال: 2002
ISSN: 0171-8630,1616-1599
DOI: 10.3354/meps233157