A possible additional site of penaeus monodon densovirus (PmDNV) infection in the gonads : an evidence of the vertical transmission of the virus | |
| Author | Fernando, Sudini Ranshaya |
| Call Number | AIT Thesis no.AQ-17-01 |
| Subject(s) | Penaeus monodon Shrimps--Diseases |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Aquaculture and Aquatic Resources Management, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. AQ-17-01 |
| Abstract | As vertical transmission of Penaeus monodon densovirus ( Pm DNV) has been suspected and thus far no evidence besides positive findings of the virus in the post larvae has come forth. In the present study, an attempt was made to determine whether Pm DNV infects gonads of P. monodon as a mode of vertical transmission of the virus and to devise a diagnostic technique for Pm DNV by hepatopancrease biopsy. The test animals were classified into highly /moderately positive and lightly positive /negative based on the severity of the infection in the respective tissues. No significant difference in the body weights of highly / moderately infected hepatopancreas to lightly positive / negative suggests low influence of Pm DNV on the growth rate of subadult shrimps. Among the shrimps that had highly/mo derately positive Pm DNV in hepatopancreas, gonads, feaces and heamolymph no significant difference was found in both males and females. Presence of Pm DNV in ovaries and feces of shrimps which had Pm DNV infection lightly /negative in hepatopancreas, suggests a non - dependent presence of the virus. However, a significant association was observed in Pm DNV detection in highly/moderately positive hemolymph to the Pm DNV infection in the hepatopancreas. Pm DNV proteins were heavily localized in the hepatopancreatic cells, intercellular space and lumen of the hepatopancreas using immunohistochemistry. Slightly positive signals were observed in the intercellular space and tissue fluid in the ovary. Various types of inclusions, suggesting on - going apoptotic process, were observed in the Pm DNV infected immature ovary. No testis was found to be highly/moderately positive by PCR or immunohistochemistry. These findings suggest that ovarian fluid is likely to be the site of Pm DNV presence, and could be the source of vertical transmission of the virus. In addition, hepatopancreas biopsy was successfully performed, with tissue diagnosis of Pm DNV by PCR and the shrimp survived well after the operation. |
| Year | 2017 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. AQ-17-01 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Aquaculture and Aquatic Resources Management (AQ) |
| Chairperson(s) | Salin, Krishna R.; |
| Examination Committee(s) | Yakupitiyage, Amararatne;Anal, Anil Kumar;Boonsirm Withyachumnarnkul |
| Scholarship Donor(s) | Uva Wellassa University, Sri Lanka;AIT Fellowship; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2017 |