## Abstract Decreased glycogen radioactivity was followed as an indicator of glycogen utilization following activation of __Strongylocentrotus purpuratus__ eggs. Within 15 minutes of exposure to sperm or ammonia, egg glycogen radioactivity decreased. The level of radioactivity in control (unfertili
Na is essential for activation of the inseminated sea urchin egg
β Scribed by Chambers, Edward L.
- Publisher
- John Wiley and Sons
- Year
- 1976
- Tongue
- English
- Weight
- 261 KB
- Volume
- 197
- Category
- Article
- ISSN
- 0022-104X
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
The presence of at least 2.5 mM Na during the first several min after insemination is requied for the activation of sea urchin eggs. Of those chemical species examined that exist entirely as cations, and which did not activate the unfertilized egg, only Li substitutes for Na. Ammonium and other amines, with pK~a~ values between 9 and 10.8, in the complete absence of Na (a) can induce nuclear activation of unfertilized eggs, and (b) permit the development of the early fertilized egg through the stage that normally requires Na.
π SIMILAR VOLUMES
Uptake and phosphorylation of externally supplied [3H]-thymidine are fully stimulated in fertilized sea urchin eggs exposed to 5.0 pg/ml aphidicolin. As in untreated controls, the rate of uptake in aphidicolin-treated eggs increases greater than 50-fold shortly after fertilization, and greater than
## Abstract Sea urchin eggs take up Ca for 10 min following insemination (determined as uptake of ^45^Ca from the SW (3)). Although 90% of this uptake occurs after the beginning of the cortical reaction and may represent external binding of Ca to the egg surface coats, there is a brief phase of upt
## Abstract Gametes and embryos of broadcast spawners are exposed to a wide range of chemical and physical stressors which may alone, or in conjunction, have serious consequences on reproductive outcomes. In this study, two Mediterranean echinoid species, __Paracentrotus lividus__ and __Sphaerechin
Changes in the intracellular Ca2+ concentration ([Ca2+]i) and the formation of actin filaments were investigated in unfertilized eggs of the sea urchin Hemicentrotus pulcherrimus after activation with a phorbol ester, 12-O-tetradecanoyl phorbol13-acetate (TPA). Intracellular Ca2+ oscillation was obs