Scruggs, J.R.*; Glas, P.S.: Protein Changes in the Embryonic Coat During Development of the Grass Shrimp, Palaemonetes pugio

The morphological changes in the embryonic coats of grass shrimp were shown by Glas, et al. (1997), but the composition of the embryonic coat has yet to be determined. This study determined that the embryonic coat protein composition of the developing grass shrimp changes over time as the embryo adds new internal envelopes. Embryos were collected during each stage of their embryonic development, and the embryonic coats were isolated. The isolates were then electrophoresed, fixed and stained for protein. Additionally, embryos were cultured in cell culture dishes, and the supernatant was removed and concentrated. The concentrate was then electrophoresed on a gradient gel, fixed and stained. The results of these experiments show a change in the position of the protein bands suggesting that the embryonic coat protein content changes as envelopes are added and then dissolved during embryonic development. There was no definitive evidence of an ovoperoxidase enzyme as found in other invertebrates. This study begins the determination of the composition of the different envelopes. This determination will be of assistance in culture of similar species that are used as food sources. Embryonic coat composition may also be of use in environmental monitoring. This study was supported by The Citadel Development Foundation (PSG) and Charleston Scientific and Cultural Education Fund (JRS).