Genetic diversity of the Caribbean spiny lobster virus, Panulirus argus virus 1 (PaV1), and the ­discovery of PaV1 in lobster postlarvae

The present study compares 13 physiological and immunological variables between a group of healthy Panulirus argus lobsters and a group of lobsters naturally infected with Panulirus argus Virus 1 (PaV1). Viral infection was determined through histopathology and PCR. Ten of the 13 variables differed significantly between the 2 groups. Using these variables, a principal component analysis yielded 2 separate clusters: one corresponding to the healthy group and the other corresponding to the infected group. In particular, infected lobsters exhibited significantly lower levels of osmotic pressure, total hemocyte counts, plasmatic proteins, and total phenoloxidase (PO) activity in plasma, as well as significantly higher levels of cholesterol and acylglycerides. These features are consistent with metabolic wasting, hyperlipidemia, and presumed immune suppression. Infection with PaV1 appears to increase the susceptibility of lobsters to some other opportunistic pathogens, as 61.1% of infected lobsters presented infestations of ciliate epibionts (Epystilis and Zoothamniun) in the gill chamber compared with 11.5% lobsters in the healthy group. Infected lobsters also showed significantly higher levels of total PO activity in degranulated hemocytes and trypsin inhibitor activity, potentially indicating activation of immune response by the PO system during the systemic infection with PaV1.

Section: Introductionmentioning

confidence: 99%

Physiological and immunological characterization of Caribbean spiny lobsters Panulirus argus naturally infected with Panulirus argus Virus 1 (PaV1)

Pascual-Jímenez¹,

Huchin-Mian²,

Simões³

et al. 2012

“…Using sterile methods, aliquots of ~15 mg of tissue or 150 µl of hemolymph in anticoagulant were incubated with 50 µl of 10% Chelex resin (w/v) and 12 µl of Proteinase K (Qiagen) at 60°C for approximately 4 h. Once tissue lysis was complete, samples were vortexed for 15 s, heated at 100°C for 10 min, vortexed briefly again, and then centrifuged at 13 600 rpm (20 000 × g) for 1 min. The DNA (supernatant) was removed and stored at either −20°C or 4°C prior to genetic analysis.For quality control, genomic DNA from each lobster was assessed by amplifying the small subunit ribosomal RNA (SSU) using 'universal' SSU primers modified from Medlin et al (1988) (see Moss et al 2006Moss et al , 2012. The amplified target DNA fragment was approximately 1800 bp in length.…”

mentioning

confidence: 99%

Distribution, prevalence, and genetic analysis of Panulirus argus virus 1 (PaV1) from the Caribbean Sea

Moss¹,

Behringer²,

Shields³

et al. 2013

Self Cite

The pathogenic virus Panulirus argus virus 1 (PaV1) was first discovered in Caribbean spiny lobsters Panulirus argus from the Florida Keys (USA) in 1999 and has since been reported in Belize, Mexico, and Cuba; its distribution in the wider Caribbean is unknown. We collected tissue samples from adult spiny lobsters from 30 locations in 14 countries bordering the Caribbean Sea and used molecular diagnostics to assay for the presence of PaV1. PaV1 occurred primarily in the northern areas of the Caribbean, where its prevalence was highest. The virus was not found in lobsters from the southeastern Caribbean, and its prevalence was lowest in the southwestern Caribbean. DNA sequence analysis was performed on a fragment of the viral DNA to examine the genetic diversity of PaV1 on a Caribbean-wide scale. Sequence variation in the viral DNA fragment was high, with 61 unique alleles identified from 9 areas. The sharing of viral alleles in lobsters from distant locations supports the hypothesis of a strong genetic connectivity among lobsters within the Caribbean, and further supports the hypothesis that postlarvae infected with PaV1 may serve to disperse the virus over long distances. KEY WORDS: Spiny lobster · Disease · Epidemiology · ConnectivityResale or republication not permitted without written consent of the publisher Dis Aquat Org 104: 129-140, 2013 the commercial harvest of P. argus in Florida, USA, totaled 42 million kg, valued at US$365.3 million (Florida Wildlife and Conservation Commission 2012). In 2010, more than 35 000 metric tons (t) of P. argus were landed worldwide (FAO Fisheries and Aquaculture Information and Statistics Service). Countries with the highest landings include Brazil, the Bahamas, Cuba, Nicaragua, Honduras, the Dominican Republic, and the USA (Vondruska 2010).In 1999, a pathogenic virus, Panulirus argus virus 1 (PaV1), was discovered infecting spiny lobsters from the Florida Keys (Shields & Behringer 2004). Prevalence of PaV1 is highest in early benthic juveniles (EBJs) and lower among larger juveniles and adults (Shields & Behringer 2004, LozanoÁlvarez et al. 2008. Lobsters with clinical disease have chalky-white hemolymph and often have a discolored carapace with a pink hue. Heavily infected lobsters are typically lethargic, cease grooming and foraging, and have lower hemolymph serum protein values compared to uninfected lobsters . Histologically, signs of PaV1 infection include a depletion of the reserve inclusion cells, hemocyte infiltration into the intertubular spaces of the hepatopancreas, focal necrosis of the hepatopancreas, and the presence of infected hemocytes in the heart, gills, and connective tissues (Li et al. 2008).Since its initial discovery in Florida, infections have been confirmed in Belize (Huchin-Mian et al. 2009), Mexico , Cuba (Cruz Quintana et al. 2011), and the US Virgin Islands . Prevalence of PaV1 in juvenile lobsters in Florida is patchy, but has historically ranged from 5 to 8%, with some locations exceeding 60% (Behringer et al. 2011). While typ...

“…The analysis involved 64 nucleotide sequences of PaV1, including the sequence obtained from infected puerulus 2 ('postlarva, offshore Mexico') caught during cruise 2 (April 2013). In total, the final dataset included 409 positions (see Montgomery-Fullerton et al 2007, Moss et al 2012 out most of the year and hence there are potentially millions of pueruli in Caribbean waters at any given time. Consistent with a lack of evidence for vertical transmission of PaV1, we did not find PaV1 in phyllosomata.…”

Section: Discussionmentioning

confidence: 99%

“…PaV1 can be transmitted by contact, but additional modes of transmission may include waterborne ) and the influx of infected larvae from other systems (Dolan et al 2014). Moss et al (2012Moss et al ( , 2013 detected PaV1 in recently settled pueruli and discovered that lobsters from distant Caribbean locations shared viral alleles, suggesting that PaV1 could be dispersed via larval transport. Yet, recent studies in Florida have found no evidence of vertical transmission of PaV1 (D. C. Behringer pers.…”

Section: Introductionmentioning

confidence: 99%

Panulirus argus virus 1 detected in oceanic postlarvae of Caribbean spiny lobster: implications for disease dispersal

Lozano‐Álvarez

Briones‐Fourzán²,

Huchin-Mian³

et al. 2015

Panulirus argus virus 1 (PaV1), a pathogenic virus that specifically attacks Caribbean spiny lobsters Panulirus argus, was recently detected in newly settled postlarvae of P. argus. As PaV1 appears not to be vertically transmitted, infected postlarvae likely acquire PaV1 from the water, but whether this can occur in oceanic waters where the planktonic larvae (phyllosomata) metamorphose into nektonic postlarvae remains unknown. Late-stage phyllosomata and postlarvae of P. argus were collected at distances of 2 to 100 km from the Caribbean coast of Mexico in 2 oceanographic cruises. Most postlarvae were caught in the upper meter of water, usually along with masses of floating Sargassum algae. A PaV1-PCR assay was used to test 169 phyllosomata (stages VI−X) and 239 postlarvae. All phyllosomata tested negative, but 2 postlarvae, 1 from each cruise, tested positive for PaV1. These postlarvae were collected at 55 and 48 km offshore over depths of 850 and 1800 m, respectively, suggesting that postlarvae can acquire PaV1 in offshore waters. We hypothesize that floating Sargassum may be an environmental reservoir for PaV1. The PaV1 allele (460 pb) found in an infected postlarva was more closely related to PaV1 alleles found in lobsters from Puerto Rico than in lobsters from any other location (including Mexico), suggesting high gene flow and long-distance dispersal of PaV1, consistent with previous studies of high genetic connectivity across the Caribbean.