ON ARTIFICIAL PARTHENOGENESIS IN SEA URCHINS

Can sea urchins beat the heat? Sea urchins, thermal tolerance and climate change

The massive die-off of the long-spined sea urchin, Diadema antillarum, a significant reef grazer, in the mid 1980s was followed by phase shifts from coral dominated to macroalgae dominated reefs in the Caribbean. While Diadema populations have recovered in some reefs with concomitant increases in coral cover, the additional threat of increasing temperatures due to global climate change has not ...

Pentamerism and Modularity in Sea Urchins

A Cytological Study of Artificial Parthenogenesis in the Sea Urchin Arbacia Punctulata

Eggs of the sea urchin Arbacia punctulata were artificially activated with hypertonic seawater. The artificially activated eggs undergo the cortical reaction which is not distinguished by a wavelike progression as in the case of inseminated eggs. The cortical granules are released at random loci at the surface of the egg and result in spaces separated by large cytoplasmic projections. Unreacted...

Evolutionary crossroads in developmental biology: sea urchins.

Embryos of the echinoderms, especially those of sea urchins and sea stars, have been studied as model organisms for over 100 years. The simplicity of their early development, and the ease of experimentally perturbing this development, provides an excellent platform for mechanistic studies of cell specification and morphogenesis. As a result, echinoderms have contributed significantly to our und...

Species-specific Sperm Adhesion in Sea Urchins

Bindin, a protein component of the acrosomal vesicle of sea urchin sperm, has been isolated from Arbacia punctulata and Strongylocentrotus purpuratus . Using this isolated bindin, we have devised a quantitative assay for bindin-mediated egg agglutination and compared the agglutination of bindin and eggs from A . punctulata and S. purpuratus . Bindin-mediated agglutination is species-specific in...