TRANSFORMATION OF PRIMARY CULTURES OF SHRIMP (PENAEUS-STYLIROSTRIS) LYMPHOID (OKA) ORGAN WITH SIMIAN-VIRUS-40 (T)-ANTIGEN

Primary cultures of lymphoid (Oka) organ from Penaeus stylirostris wer e transformed with naked or Lipofectin-mediated pSV-3 neo, a shuttle v ector containing the tumor (T) antigen gene from Simian virus-40. The transformed cells, OKTr-1 and OKTr-23, exhibited the following charact eristics: rounded morphology forming grapelike aggregates, loosely adh esive, increased growth rate in Medium-199, resistance to G-418 (a neo mycin analog marker in the shuttle vector), cloning efficiencies of 68 .7% and 36.7% in soft agarose, respectively, and stability in liquid n itrogen storage, Immunofluorescence staining (IFA) of the transformed cells using a monoclonal antibody against SV-40 tumor antigen showed p ositive results. In contrast, primary cell cultures exhibited fibrobla st-like morphology and formed a tight, adhesive monolayer on the surfa ce of the culture vessel. They were sensitive to G-418, and showed neg ative results with IFA. To date, OKTr-1 and OKTr-23 have undergone 44 and 18 passages, respectively. Primary cultures of the lymphoid organ have not been successfully passaged beyond the primary stage.