Plastic debris litters aquatic habitats globally, the majority of which is microscopic (< 1 mm), and is ingested by a large range of species. Risks associated with such small fragments come from the material itself and from chemical pollutants that sorb to it from surrounding water. Hazards associated with the complex mixture of plastic and accumulated pollutants are largely unknown. Here, we show that fish, exposed to a mixture of polyethylene with chemical pollutants sorbed from the marine environment, bioaccumulate these chemical pollutants and suffer liver toxicity and pathology. Fish fed virgin polyethylene fragments also show signs of stress, although less severe than fish fed marine polyethylene fragments. We provide baseline information regarding the bioaccumulation of chemicals and associated health effects from plastic ingestion in fish and demonstrate that future assessments should consider the complex mixture of the plastic material and their associated chemical pollutants.

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Phylogenetic relationships among herpesviruses (HVs) of mammals, birds, and reptiles have been studied extensively, whereas those among other HVs are relatively unexplored. We have reconstructed the phylogenetic relationships among 13 fish and amphibian HVs using maximum likelihood and Bayesian analyses of amino acid sequences predicted from parts of the DNA polymerase and terminase genes. The relationships among 6 of these viruses were confirmed using the partial DNA polymerase data plus the complete sequences of the terminase, helicase, and triplex protein genes; the position of these viruses among all other sequenced HVs was also investigated using the complete terminase gene. The results established the monophyly of the fish and amphibian HVs (Alloherpesviridae) separate from the HVs of mammals, birds, and reptiles (Herpesviridae) and the single recognized HV of bivalve mollusks (Malacoherpesviridae) in the order Herpesvirales. Two major clades in the family Alloherpesviridae were recognized: one consisting of viruses from cyprinid and anguillid hosts and the other of viruses from ictalurid, salmonid, acipenserid, and ranid hosts. A comparison of virus and host phylogenies suggested that closely related HVs in this family may have coevolved with their hosts, whereas significant codiversification was not apparent for the more distantly related viruses.KEY WORDS: Alloherpesviridae · Fish herpesviruses · Frog herpesviruses · Phylogeny · Coevolution· DNA polymerase · Terminase Resale or republication not permitted without written consent of the publisherDis Aquat Org 84: [179][180][181][182][183][184][185][186][187][188][189][190][191][192][193][194] 2009 pesviridae, divided into the subfamilies Alphaherpesvirinae, Betaherpesvirinae, and Gammaherpesvirinae) containing mammalian, avian, and reptilian viruses, one (Alloherpesviridae) containing fish and amphibian viruses, and one (Malacoherpesviridae) containing a single virus, OsHV1. The taxonomic structure of the family Herpesviridae has been well established phylogenetically, and the viruses are characterized by approximately 43 homologous genes that were presumably inherited from a common ancestor (McGeoch et al. 2006). The erection of the 2 new families was driven by the findings that these viruses are but tenuously related to the fish and amphibian HVs, which share at least 13 homologous genes with each other (Aoki et al. 2007), and that OsHV1 is related only marginally to all other HVs (Davison et al. 2005b). Indeed, the best, and perhaps only, sequence-based evidence supporting a common ancestry for all HVs resides in a single gene, that encoding the putative ATPase subunit of terminase (hereafter terminase; an enzyme complex involved in packaging DNA into capsids), in which 5 regions are conserved (Davison 1992(Davison , 2002. This protein is also conserved to a lesser extent in T4-like bacteriophages in the family Myoviridae (Davison 1992). Indeed, the perceived utilization of a similar enzyme complex for packaging DNA into preformed capsids...

dThree alloherpesviruses are known to cause disease in cyprinid fish: cyprinid herpesviruses 1 and 3 (CyHV1 and CyHV3) in common carp and koi and cyprinid herpesvirus 2 (CyHV2) in goldfish. We have determined the genome sequences of CyHV1 and CyHV2 and compared them with the published CyHV3 sequence. The CyHV1 and CyHV2 genomes are 291,144 and 290,304 bp, respectively, in size, and thus the CyHV3 genome, at 295,146 bp, remains the largest recorded among the herpesviruses. Each of the three genomes consists of a unique region flanked at each terminus by a sizeable direct repeat. The CyHV1, CyHV2, and CyHV3 genomes are predicted to contain 137, 150, and 155 unique, functional protein-coding genes, respectively, of which six, four, and eight, respectively, are duplicated in the terminal repeat. The three viruses share 120 orthologous genes in a largely colinear arrangement, of which up to 55 are also conserved in the other member of the genus Cyprinivirus, anguillid herpesvirus 1. Twelve genes are conserved convincingly in all sequenced alloherpesviruses, and two others are conserved marginally. The reference CyHV3 strain has been reported to contain five fragmented genes that are presumably nonfunctional. The CyHV2 strain has two fragmented genes, and the CyHV1 strain has none. CyHV1, CyHV2, and CyHV3 have five, six, and five families of paralogous genes, respectively. One family unique to CyHV1 is related to cellular JUNB, which encodes a transcription factor involved in oncogenesis. To our knowledge, this is the first time that JUNB-related sequences have been reported in a herpesvirus.

We cloned a cDNA and the gene for Japanese flounder TNF. The TNF cDNA consisted of 1217 bp, which encoded 225 amino acid residues. The identities between Japanese flounder TNF and members of the mammalian TNF family were ∼20–30%. The positions of cysteine residues that are important for disulfide bonds were conserved with respect to those in mammalian TNF-α. The Japanese flounder TNF gene has a length of ∼2 kbp and consists of four exons and three introns. The positions of the exon-intron junction positions of Japanese flounder TNF gene are similar to those of human TNF-α. However, the length of the first intron of Japanese flounder is much shorter than that of the human TNF-α gene. There are simple CA or AT dinucleotide repeats in the 5′-upstream and 3′-downstream regions of the Japanese flounder TNF gene. Southern blot hybridization indicted that Japanese flounder TNF exists as a single copy. Expression of Japanese flounder TNF mRNA is greatly induced after stimulation of PBLs with LPS, Con A, or PMA. These results indicated that Japanese flounder TNF is more like mammalian TNF-α than mammalian lymphotoxin-α, with respect to its gene structure, length of amino acid sequence, number and position of cysteine residues, and regulation of gene expression.