White Spot Syndrome Virus Infecting To Haemocytes Of Shrimp And Ontogenesis Of The Haemocytes

In this paper, monoclonal antibodies (Mabs) against haemocytes of shrimp (Litopenaeus vannamei) were produced. From these Mabs, Mabs against three types of haemocytes and against granular haemocytes were selected respectively by labelled streptavidin biotin (LSAB) method and types of Mabs were identified by Western-blot.Shrimp periodically sampled were investigated for granular haemocytes in haemolymph, when shrimp were subjected to infection of white spot symptom virus (WSSV). LSAB staining analysis with a specific Mab against granular haemocytes of L. vannamei indicated after WSSV infection, cytoplasm of granular haemocytes of shrimpincreased; from Day 1 to Day 3, the number of granular haemocytes increased and proportions of granular haemocytes increased from 15.2% to 45.9%. From Day 3 to Day 8 proportions of granular haemocytes were in a slightly decreasing trend, but still higher than control group that showed no great difference from start to the end with 15.2%. After shrimp were infected by WSSV, the number of granular haemocytes reduced in the haematopoietic tissue and more positive haemocytes appeared at the verge of the haematopoietic tissue; the lymphoid organ was found that positive cells were not only located in the lumen of the lymphoid organ tubules as healthy one, positive granules were also densely interspersed in the outer portion of the tubule stromal matrix cell.Mabs against three types of haemocytes of shrimp L. vannamei, were employed to study the ontogenesis of haemocytes. L aid eggs, nauplius, zoea, mysis and postlarvae of shrimp were collected and cryosections were probed with Mabs by immunofluence antibody technique (IFAT). The results showed antigens were detected at embryo of multi-cell stage and single haemocytes appeared in nauplius. The Mab specific for granular haemocytes was used to detect granular haemocytes and granular haemocytes appeared in the stage of zoea...