A novel approach for investigating glycan involvement in embryonic cellular interactions. III. whole embryo periodate studies

Abstract

Periodate oxidation has been widely used to degrade the carbohydrate components of molecules to help determine the role of sugars in molecular function. In this study, 24.5‐26 hr early gastrula Lytechinus pictus sea urchin embryos were incubated with specific ultra‐low concentrations of sodium (meta) periodate that degrades some carbohydrates by selectively oxidizing C‐C bonds between vicinal diols. Incubations were carried out in 15 degrees C artificial seawater in 96 well microplates for 24‐25 hrs. After the incubation period, embryos were examined for viability, fixed in 5% formaldehyde, and the morphological characteristics of 5664 embryos were quantitatively assessed as embryos possessing complete attached archenterons, incomplete unattached archenterons, no invagination, exogastrulation, or embryos that were dead. At 1.2x10−6 ‐3.9x10−5 mg periodate/ml 15‐30% of the embryos were swimming and possessed incomplete unattached archenterons, while the controls without periodate displayed 2.3% incomplete archenterons. At higher concentrations of periodate (7.8x10−5‐1.0x10−2 mg periodate/ml), embryo death occurred. Using a two‐sample equal variances t‐test, the numbers of unattached archenterons in the 1.2x10−6‐3.9 x10−5 mg periodate/ml treated embryos were significantly different from those in the controls without periodate at a p value of less than 0.001. The use of periodate in probing whole, living embryos is novel and could become widely used to help identify the role of glycans in interacting systems (Supported by NIH NIGMS SCORE (S0648680), MARC, RISE, the Joseph Drown Foundation, and the Sidney Stern Memorial Trust).