*** 9528167 Cheng This Small Business Innovation Research Phase II project is designed to help solve a major problem for the oyster industry along the mid-Atlantic seaboard of the United States. Since 1957, oysters in the Delaware and Chesapeake Bays have suffered mass moralities due to lethal diseases caused by two protistan parasites, Haplosporidium nelsoni (MSX) and Perkinsus marinus (Dermo). Based on the results of Phase I research, it now appears fairly certain that a yet uncharacterized saccharide, designated as lathyrose, that occurs on the surfaces of a high percentage of hemocytes of oysters, Crassostrea virginica, from certain areas along the Atlantic coast of the U.S. and along the Gulf of Mexico coast may serve as a molecular marker for innate resistance to Haplosporidium nelsoni (MSX). Lathyrose-positive hemocytes will agglutinate when presented with the Lathyrose odoratus lectin. Phase II research will survey for the presence of lathyrose in large samples of oysters ( > 400) from Maine to the Gulf coast. This survey is designed to accurately determine whether there is a high degree of correlation between the occurrence of lathyrose and absence of MSX. If this phenomenon is successfully established, then trays of lathyrose-positive oysters will be transplanted to Inlet Creek, Sullivan's Island, Charleston County, South Carolina, where about 28% of the native oysters harbor MSX. This will be done to field test the resistance of lathyrose-positive oysters to MSX. Phase II research will then make genetic crosses to develop strains of lathyrose-positive oysters resistant to MSX and develop (and eventually market) simple diagnostic kit to identify oysters resistant to MSX. ***
