Cell cycle components and their potential impact on the development of continuous in vitro penaeid cell replication.

In vitro prawn cell culture has yet to produce an established cell line. In an effort to establish some understanding of the cellular blockage that prohibits their division in vitro we conducted several studies to characterize the cytoskeletal components of hemocytes and found no cells undergoing mitosis. Following this discovery, a molecular analysis of cell division regulatory proteins was performed. Cell cycle regulatory proteins (cyclins) have been identified as essential components in the progression of all eukaryotic cells through the cell cycle. We report here the identification of cyclin A and cyclin B proteins and their cofactor (p34(cdc2)) in making up the mitosis promoting factor (MPF) in protein extracts from egg and muscle tissues of Penaeus vannamei. Molecular weight analysis confirmed the size of the target proteins to be similar to the same proteins identified in the Atlantic surf clam (Spisula solidissima).

Procedure for selecting monoclonal antibodies for use in a ligand displacement assay of serum antibody levels.

Monoclonal antibodies for use in a ligand displacement assay were selected for specificity and affinity/avidity properties that result in their release and displacement in the presence of specific sample antibody but not in the presence of antibodies against other antigens. A screening process is described which involves measurement of displacement of antibody by an ELISA procedure using an enzyme labeled anti-immunoglobulin, providing a means of demonstrating usefulness of a candidate antibody in a ligand displacement format without necessitating the production of enzyme conjugates of each candidate antibody to be screened. The procedure was used to screen a set of eleven monoclonal antibodies (initially selected for anti-Trichinella spiralis specificity by conventional screening methods), and successfully discriminated between antibodies which were useful in the ligand displacement format and those which were not.

Natural Enterovirus and Fecal Coliform Contamination of Gulf Coast Oysters.

The numbers of fecal coliforms and enteroviruses present in oysters and/or their growing waters of two Mississippi reefs were determined over a 12-month period. Bacterial and viral levels reflected the classification of the waters at each location as set by the Mississippi State Board of Health in compliance with the National Shellfish Sanitation Program, but statistically significant correlations between these levels were not observed. Twelve viral isolates were found at an approved oyster harvesting location, eight of which were identified as poliovirus type 1. At the prohibited site, 146 viruses were isolated including poliovirus types 1 and 2, echovirus type 24 and several isolates which remain to be identified. The number of virus isolates from samples from each location represented approximately 35% of the number of plaques observed; however, no consistent ratio of plaque to confirmed virus was demonstrated. The results suggest that the fecal coliform levels in oyster growing waters do not reflect the level of virus contaminaton in either approved or prohibited waters.

Fish cell culture characteristics of a cell line from the silver perch Bairdiella chrysura.

A cell designated SP-1 was established from tissue of the silver perch, Bairdiella chrysura. Cells were fibroblast-like and grew best at 26 degrees C in Leibovitz medium (L-15) containing 15% fetal bovine serum and 0.150 M sodium chloride. Passage 1 to passage 9 SP-1 cells contained a chromosome number of 48; at passages 27 and 50 the modal numbers were 51 and 54, respectively. Confirmation of the origin of SP-1 cells was made by the cytotoxic antibody dye-exclusion test. This cell line supported the growth of lymphocystis virus from the silver perch but was not found to replicate various other fish and mammalian viruses.