Sea Urchin Embryo Model Research Articles

Periodate oxidation of sea urchin hyalin(s): A glycobiological study towards understanding of hyalin's function as a specific cell adhesion molecule

Hyalin (Hy), a set of large glycoproteins containing 2‐3% carbohydrate appears to be a specific cell adhesion molecule in the sea urchin embryo model. Sodium (meta) periodate (PI) can selectively degrade carbohydrate by oxidizing the C‐C bonds between vicinal diols. Untreated Strongylocentrotus purpuratus Hy blocked the adhesion of the tip of the archenteron to the roof of the blastocoel (the specific adhesive interaction under study) in two assays: (1) a microplate assay using live Lytechinus pictus embryos and (2) using dissected pieces of the archenteron and blastocoel roof. Hy cross reacts between these two species. PI treated Hy did not block this interaction in either assay. The microplate analysis, with over 16,000 L. pictus embryos, indicated that 6 hr PI treated Hy (0.17‐0.34 mg treated Hy/ml low calcium artificial sea water ‐LCSW) did not block the cellular interaction, while untreated Hy (0.17‐0.34 mg untreated Hy/ml LCSW) did. 76.4‐77.2% ± 2% of the embryos in PI treated Hy possessed complete archenterons, while 2.7‐7.6% ± 12% possessed complete archenterons in the untreated Hy samples with a p value of less than 0.001. Similar results were obtained using the dissected pieces assay. While this study suggests that Hy carbohydrate is involved in Hy function, further studies are needed to determine if PI is also affecting Hy in other ways (Supported by NIH NIGMS SCORE (S0648680), MARC, RISE, the Joseph Drown Foundation and the Sidney Stern Memorial Trust).

Research Article: In vivo Evaluation of Indolyl Glyoxamides in the Phenotypic Sea Urchin Embryo Assay

We have devised a 'one-pot' phenotypic in vivo assay for the rapid evaluation of potential tubulin inhibitors using the sea urchin embryo model. An effect of a small molecule on two specific developmental stages of sea urchin embryo, namely: (i) fertilized egg test for antimitotic activity and (ii) behavioral monitoring of a free-swimming blastulae for changes in the embryo swimming pattern could be quantified by a threshold concentration resulting in respective abnormalities. Derivatives of the clinical candidate D-24851 featured good correlation between activity in tubulin polymerization assay and our in vivo data. Importantly, we demonstrated that in these series, the N-substitution of indole is non-essential to attain profound in vitro and cellular effects.