RESUMO
OBJECTIVE: To identify whether black tiger prawns (Penaeus monodon) in the Weipa region of the Gulf of Carpentaria, Queensland, are free of gill-associated virus (GAV) and Mourilyan virus (MoV), which are endemic in P. monodon along the east coast of Queensland. PROCEDURE: Preliminary screening suggested that Weipa might be a source of P. monodon that are free of GAV and MoV. To assess this, more than 150 prawns captured near Weipa were maintained locally in tanks for 2 weeks and bled three times as a stressor to promote higher-level infections. The existence of GAV and MoV in lymphoid organ tissue was then determined using real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Some prawns were maintained in tanks for an additional 75 days before being tested. RESULTS: Real-time qRT-PCR did not detect GAV in any of 33 pools of RNA isolated from the 166 prawns tested. MoV was detected in five pools of RNA at extremely low viral RNA copy numbers close to the sensitivity threshold of the test. MoV was also detected at a similar low copy number in one of nine pearl-oyster mantle samples used as negative controls. CONCLUSIONS: GAV infection is either absent or, like MoV, potentially present at a very low prevalence in juvenile P. monodon inhabiting the inshore waters at Weipa. This region can thus be recommended as a good source of P. monodon certifiable as specific pathogen-free for GAV and MoV, which is desirable for domestication and selective breeding programs in Australia.
Assuntos
Bunyaviridae/isolamento & purificação , Penaeidae/virologia , Roniviridae/isolamento & purificação , Animais , Aquicultura , Bunyaviridae/genética , DNA Complementar/biossíntese , Feminino , Brânquias/virologia , Masculino , Prevalência , Queensland , RNA Viral/genética , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Roniviridae/genética , Estresse FisiológicoRESUMO
Hexachlorobenzene (HCB) is a persistent organic pollutant that has been found to be bioaccumulating in several Arctic regions of the world. The response of embryonic cells to HCB exposure has been evaluated for several different cytotoxic responses, including genotoxic effects. NIH 3T3 (mouse) and WS1 (human) embryonic cells were exposed to HCB at 1 and 10 times the average newborn cord blood concentrations of Alaska Arctic natives. Assays were then performed to determine the subsequent effects of HCB on overall cell number, viability, cell growth fraction and long-term survival, as well as specific biochemical and molecular responses. Exposure of both cell types to HCB results in cell membrane damage, a short-term decrease in cell number, increased DNA strand breaks, and a long-term decrease in colony survival. WS1 cells also undergo cell-cycle arrest and modulations in glutathione concentration after exposure to HCB. In addition, NIH 3T3 cells exhibit an increased number of transformed foci after repeated exposure to HCB. This study demonstrates that relevant environmental concentrations of HCB have significant effects on mammalian embryonic cells in culture.
