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.
In 2009, juvenile pallid sturgeon Scaphirhynchus albus, reared at the Blind Pony State Fish Hatchery (Missouri, USA) to replenish dwindling wild stocks, experienced mass mortality. Histological ...examination revealed extensive necrosis of the haematopoietic tissues, and a virus was isolated from affected organs in cell culture and then observed by electron microscopy. Experimental infection studies revealed that the virus is highly pathogenic to juvenile pallid sturgeon, one of several species of sturgeon currently listed as Endangered. The DNA sequence of the full length major capsid protein gene of the virus was identical to that of the species Frog virus 3 (FV3), the type species for the genus Ranavirus, originally isolated from northern leopard frog Lithobates pipiens. Although FV3 infections and epizootics in amphibians and reptiles are well documented, there is only 1 prior report of a natural infection of FV3 in fish. Our results illustrate the broad potential host range for FV3, with the known potential to cause significant mortality in poikilothermic vertebrates across 3 taxonomic classes including bony fishes, anuran and caudate amphibians, and squamate and testudine reptiles.
Whirling disease, caused by the pathogen Myxobolus cerebralis, afflicts several salmonid species. Rainbow trout are particularly susceptible and may suffer high mortality rates. The disease is ...persistent and spreading in hatcheries and natural waters of several countries, including the U.S.A., and the economic losses attributed to whirling disease are substantial. In this study, genome-wide expression profiling using cDNA microarrays was conducted for resistant Hofer and susceptible Trout Lodge rainbow trout strains following pathogen exposure with the primary objective of identifying specific genes implicated in whirling disease resistance.
Several genes were significantly up-regulated in skin following pathogen exposure for both the resistant and susceptible rainbow trout strains. For both strains, response to infection appears to be linked with the interferon system. Expression profiles for three genes identified with microarrays were confirmed with qRT-PCR. Ubiquitin-like protein 1 was up-regulated over 100 fold and interferon regulating factor 1 was up-regulated over 15 fold following pathogen exposure for both strains. Expression of metallothionein B, which has known roles in inflammation and immune response, was up-regulated over 5 fold in the resistant Hofer strain but was unchanged in the susceptible Trout Lodge strain following pathogen exposure.
The present study has provided an initial view into the genetic basis underlying immune response and resistance of rainbow trout to the whirling disease parasite. The identified genes have allowed us to gain insight into the molecular mechanisms implicated in salmonid immune response and resistance to whirling disease infection.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In ruminants, the period from fertilization to implantation is relatively prolonged, and the survival of embryos depends on uterine secretions known as histotroph. Our objective was to determine if ...the pre-breeding diet affected histotroph proteomes in beef cattle. Cows were assigned to one of four diets: a control diet (CON), a high-protein diet (PROT), a high-fat diet (OIL), or a high-protein and high-fat diet (PROT + OIL). After 185 days on these diets, an intravaginal progesterone implant (CIDR) was inserted for 7 days. At 9 days after CIDR removal, animals with a corpus luteum were selected (n = 16; 4 per treatment). Proteins were isolated from the histotroph collected by uterine lavage and analyzed with liquid chromatography–tandem mass spectrometry. Over 2000 proteins were expressed (n ≥ 3 cows per treatment), with 1239 proteins being common among all of the groups. There were 20, 37, 85, and 123 proteins unique to CON, PROT + OIL, PROT, and OIL, respectively. Relative to CON, 23, 14, and 51 proteins were differentially expressed in PROT + OIL, PROT, and OIL, respectively. Functional analysis found that 53% of histotroph proteins were categorized as extracellular exosome, 3.28% as cell–cell adhesion, and 17.4% in KEGG metabolic pathways. Differences in proteomes among treatments support the idea that pre-breeding diet affects histotroph. Understanding the impact of diet on histotroph proteins may help improve conception rates.
Abstract
Sensory organs must develop alongside the skull within which they are largely encased, and this relationship can manifest as the skull constraining the organs, organs constraining the skull, ...or organs constraining one another in relative size. How this interplay between sensory organs and the developing skull plays out during the evolution of sensory diversity; however, remains unknown. Here, we examine the developmental sequence of the cochlea, the organ responsible for hearing and echolocation, in species with distinct diet and echolocation types within the ecologically diverse bat super‐family Noctilionoidea. We found the size and shape of the cochlea largely correlates with skull size, with exceptions of
Pteronotus parnellii
, whose high duty cycle echolocation (nearly constant emission of sound pulses during their echolocation process allowing for detailed information gathering, also called constant frequency echolocation) corresponds to a larger cochlear and basal turn, and
Monophyllus redmani
, a small‐bodied nectarivorous bat, for which interactions with other sensory organs restrict cochlea size. Our findings support the existence of developmental constraints, suggesting that both developmental and anatomical factors may act synergistically during the development of sensory systems in noctilionoid bats.
Impairment of fish immune function as a consequence of polluted aquatic environments can result in changes in susceptibility to disease. In this study, we investigated the effects of two widely used ...insecticides, chlorpyrifos (CP) and esfenvalerate (EV), and a pathogen, infectious hematopoietic necrosis virus (IHNV), singly and in combination, on survival and cytokine (Mx protein, IL-1β, TGF-β and IGF-1) expression in juvenile Chinook salmon. Fish were exposed for 96
h to sublethal concentrations of CP (3.7
μg
L
−1) or EV (0.08
μg
L
−1), allowed to recover in clean water for seven days, then exposed to IHNV (6.4
×
10
5
TCID
50
mL
−1) for 1.5
h. Mortality was recorded daily, and spleen and anterior kidney samples were collected on day 4 (after CP or EV treatment), day 20 and day 60 (after CP or EV treatment and subsequent IHNV exposure) of the experiment.
Significant mortality after 60 days was observed following exposure to EV (17%) or IHNV (20%), and prior insecticide exposure did not synergize the acute effects of pathogen treatment. By day 4, exposure to CP as well as EV led to a significant decrease of Mx protein and IL-1β expression; by day 20, EV-exposed fish significantly overexpressed IL-1β. Mx protein transcription was up-regulated in spleen and kidney of all IHNV-exposed fish groups by day 20. All but one treatment (EV) led to significantly decreased IGF-1 transcription in spleen on days 20 and 60, whereas a short-term increase was seen after CP exposure (day 4). In kidney, decreases of IGF-1 transcription were less pronounced. TGF-β transcription was up-regulated in CP/IHNV and EV/IHNV exposure groups.
Our results indicate that CP and EV alter the expression of cytokines, but this did not negatively affect the ability of fish to survive a subsequent exposure to IHNV. Induced TGF-β transcription indicated that the combined stressors affected fish in a synergistic manner, but the consequences are unknown. Increased transcription of Mx protein was a reliable indicator of virus exposure.
Cyprinid herpesvirus 1 (CyHV1) infects all scaled and color varieties of common carp Cyprinus carpio, including koi. While it is most often associated with unsightly growths known as 'carp pox,' the ...underlying lesion (epidermal hyperplasia) can arise from a variety of disease processes. CyHV1-induced epidermal hyperplasia may occur transiently in response to water temperature, and thus histopathology cannot be used in isolation to assess CyHV1 infection status. To address this problem, here we describe a PCR assay targeted to the putative thymidine kinase gene of CyHV1. The PCR assay generates a 141 bp amplicon and reliably detects down to 10 copies of control plasmid DNA sequence (analytic sensitivity). The PCR does not cross-detect genomic DNA from cyprinid herpesvirus 2 and 3 (analytic specificity). The CyHV1 PCR effectively detected viral DNA in koi and common carp sampled from various locations in the UK, USA, Brazil, and Japan. Viral DNA was detected in both normal appearing and grossly affected epidermal tissues from koi experiencing natural epizootics. The new CyHV1 PCR provides an additional approach to histopathology for the rapid detection of CyHV1. Analysis of the thymidine kinase gene sequences determined for 7 PCR-positive carp originating from disparate geographical regions identified 3 sequence types, with 1 type occurring in both koi and common carp.
Outbreaks with mass mortality among common carp Cyprinus carpio carpio and koi Cyprinus carpio koi have occurred worldwide since 1998. The herpes-like virus isolated from diseased fish is different ...from Herpesvirus cyprini and channel catfish virus and was accordingly designated koi herpesvirus (KHV). Diagnosis of KHV infection based on viral isolation and current PCR assays has a limited sensitivity and therefore new tools for the diagnosis of KHV infections are necessary.
A robust and sensitive PCR assay based on a defined gene sequence of KHV was developed to improve the diagnosis of KHV infection. From a KHV genomic library, a hypothetical thymidine kinase gene (TK) was identified, subcloned and expressed as a recombinant protein. Preliminary characterization of the recombinant TK showed that it has a kinase activity using dTTP but not dCTP as a substrate. A PCR assay based on primers selected from the defined DNA sequence of the TK gene was developed and resulted in a 409 bp amplified fragment. The TK based PCR assay did not amplify the DNAs of other fish herpesviruses such as Herpesvirus cyprini (CHV) and the channel catfish virus (CCV). The TK based PCR assay was specific for the detection of KHV and was able to detect as little as 10 fentograms of KHV DNA corresponding to 30 virions. The TK based PCR was compared to previously described PCR assays and to viral culture in diseased fish and was shown to be the most sensitive method of diagnosis of KHV infection.
The TK based PCR assay developed in this work was shown to be specific for the detection of KHV. The TK based PCR assay was more sensitive for the detection of KHV than previously described PCR assays; it was as sensitive as virus isolation which is the golden standard method for KHV diagnosis and was able to detect as little as 10 fentograms of KHV DNA corresponding to 30 virions.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Withering syndrome (WS) is a disease of wild and cultured abalone caused by a Rickettsiales-like prokaryote (WS-RLP). This study compared the pathologic changes that occur during the progression of ...WS in red abalone to those caused by environmental stresses consisting of elevated temperature and food limitation and determined the impact of these stressors on WS prevalence and intensity. Farmed red abalone were administered a feed-based oxytetracycline therapeutic treatment to assure WS-RLP-free status prior to initiation of the experiment. Groups were then held in each of eight combinations of exposed vs. unexposed to WS-RLP, elevated vs. ambient temperature, and high vs. low food supply, for 447 days. Mortality was associated with starvation and disease but not elevated temperature alone. Elevated temperature significantly affected WS-RLP transmission: only 1.7% of WS-RLP- exposed abalone held at ambient temperature (12.3
°C) became infected compared to at least 72% of those held at elevated temperature (18.7
°C). Among exposed abalone at elevated temperature, fed animals exhibited greater infection prevalence but not greater infection intensity or digestive gland changes than starved animals, suggesting that abalone acquire infections by ingesting contaminated food. Food, temperature, WS-RLP exposure, and most of their interactions had significant effects on body condition and foot atrophy. Immunohistochemical detection of cell proliferation and apoptosis revealed no differences between normal digestive gland and that infected with WS-RLP. Body mass shrinkage, foot atrophy, elevated mortality, and decreased foot and digestive gland glycogen were observed in both WS-affected and starved, unexposed abalone, with the WS-RLP-exposed, starved group held at elevated temperature faring worst. Among exposed and unexposed animals, food supply but not temperature affected body mass and growth. These data demonstrate that the high morbidity and mortality exhibited by WS-RLP-infected abalone is a consequence of disease and not direct thermal stress. Drug residue analysis indicated oxytetracycline concentrations of up to 600
ppm in the digestive gland at 38 days post-treatment, an unusual degree of tissue retention of this therapeutant.
Rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta) represent two salmonid genera separated for 15--20 million years. cDNA sequences were determined for the classical MHC class I heavy ...chain gene UBA and the MHC class II beta-chain gene DAB from 15 rainbow and 10 brown trout. Both genes are highly polymorphic in both species and diploid in expression. The MHC class I alleles comprise several highly divergent lineages that are represented in both species and predate genera separation. The class II alleles are less divergent, highly species specific, and probably arose after genera separation. The striking difference in salmonid MHC class I and class II evolution contrasts with the situation in primates, where lineages of class II alleles have been sustained over longer periods of time relative to class I lineages. The difference may arise because salmonid MHC class I and II genes are not linked, whereas in mammals they are closely linked. A prevalent mechanism for evolving new MHC class I alleles in salmonids is recombination in intron II that shuffles alpha 1 and alpha 2 domains into different combinations.
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