This document summarizes research on Ranavirus, a pathogen affecting ectothermic vertebrates globally. Ranavirus is a DNA virus in the family Iridoviridae that can cause disease and mortality in amphibians, reptiles, and fish. The virus has been detected worldwide and is associated with die-offs in over 100 amphibian species, 30 reptile species, and 50 fish species. Gross signs of infection can include hemorrhage, swelling, and necrosis. Microscopic lesions often involve endothelial and epithelial cell necrosis. Research is ongoing to understand Ranavirus ecology, transmission, pathology, and potential for contributing to host declines.
Ecology of Ranaviruses: State of Understandingmgray11
Presentation on the basic ecology of ranaviruses and mechanisms that may be contribute to this pathogen's emergence. By Dr. Matt Gray (University of Tennessee, Center for Wildlife Health)
Are ranaviruses capable of causing local population extinctions and contributing to species declines? By Dr. Matt Gray (University of Tennessee, Center for Wildlife Health)
Dr. Sid Thakur - Antimicrobial Resistance: Do We Know Everything?John Blue
Antimicrobial Resistance: Do We Know Everything? - Dr. Sid Thakur, Assistant Professor, North Carolina State University, from the 2013 NIAA Merging Values and Technology conference, April 15-17, 2013, Louisville, KY, USA.
More presentations at http://www.trufflemedia.com/agmedia/conference/2013-niaa-merging-values-and-technology
Ecology of Ranaviruses: State of Understandingmgray11
Presentation on the basic ecology of ranaviruses and mechanisms that may be contribute to this pathogen's emergence. By Dr. Matt Gray (University of Tennessee, Center for Wildlife Health)
Are ranaviruses capable of causing local population extinctions and contributing to species declines? By Dr. Matt Gray (University of Tennessee, Center for Wildlife Health)
Dr. Sid Thakur - Antimicrobial Resistance: Do We Know Everything?John Blue
Antimicrobial Resistance: Do We Know Everything? - Dr. Sid Thakur, Assistant Professor, North Carolina State University, from the 2013 NIAA Merging Values and Technology conference, April 15-17, 2013, Louisville, KY, USA.
More presentations at http://www.trufflemedia.com/agmedia/conference/2013-niaa-merging-values-and-technology
GWAS analysis of QTL for resistance against Edwardsiella ictaluri in F2 inter...Golden Helix
Infectious diseases pose significant threats to the catfish industry. Enteric septicemia of catfish (ESC) caused by Edwardsiella ictaluri is the most devastating disease for catfish aquaculture, causing huge economic losses annually. Channel catfish and blue catfish exhibit great contrast in resistance against ESC, with blue catfish being highly resistant. As such, the interspecific hybrid backcross progenies provide an ideal system for the analysis of resistance QTL. In this study, we conducted GWAS analysis to locate genomic regions associated with ESC resistance by selectively genotyping the first generation backcross progenies with the catfish 690K SNP arrays. Two genomic regions on linkage group (LG) 1 and LG23 were determined to be significantly associated with ESC resistance as revealed by a mixed linear model and family-based association test. A number of genes within QTL have known functions in immunity, making them potential candidates as disease resistance genes. For instance, seven genes on LG1 (nck1, agtr1, trpc1, abi1, apbb1ip, actr3b, and vav3) and three genes on LG23 (mrc1l, prkcq, and gata3) were involved in immune-related functions. These genes mainly function in signaling pathways of phagocytosis and T-cell activation, suggesting their roles in disease resistance. This study demonstrated the power of GWAS analysis for the identification of QTL in the hybrid system. We previously reported one QTL in LG1 using third generation backcross progenies, which was validated here in the first generation backcrosses, suggesting that this QTL is operating in various populations of a broad genetic background, making it useful for application in marker-assisted selection.
A presentation as a webinar for the Winn Feline Foundation that focuses on recent findings related to the signatures of selection in the domestic cat genome
BSAVA Manual of Canine and Feline Ultrasonography.pdfLuong Manh
Cuốn sách "Chẩn đoán siêu âm chó và mèo" này được Lương Mạnh chọn lọc từ hàng trăm cuốn sách chẩn đoán hình ảnh thú nhỏ và đánh gia đây là cuốn sách ngắn gọn, dễ học và kiến thức thực tiễn nhất xin được gửi tặng tới mọi người (sách tiếng anh).
GWAS analysis of QTL for resistance against Edwardsiella ictaluri in F2 inter...Golden Helix
Infectious diseases pose significant threats to the catfish industry. Enteric septicemia of catfish (ESC) caused by Edwardsiella ictaluri is the most devastating disease for catfish aquaculture, causing huge economic losses annually. Channel catfish and blue catfish exhibit great contrast in resistance against ESC, with blue catfish being highly resistant. As such, the interspecific hybrid backcross progenies provide an ideal system for the analysis of resistance QTL. In this study, we conducted GWAS analysis to locate genomic regions associated with ESC resistance by selectively genotyping the first generation backcross progenies with the catfish 690K SNP arrays. Two genomic regions on linkage group (LG) 1 and LG23 were determined to be significantly associated with ESC resistance as revealed by a mixed linear model and family-based association test. A number of genes within QTL have known functions in immunity, making them potential candidates as disease resistance genes. For instance, seven genes on LG1 (nck1, agtr1, trpc1, abi1, apbb1ip, actr3b, and vav3) and three genes on LG23 (mrc1l, prkcq, and gata3) were involved in immune-related functions. These genes mainly function in signaling pathways of phagocytosis and T-cell activation, suggesting their roles in disease resistance. This study demonstrated the power of GWAS analysis for the identification of QTL in the hybrid system. We previously reported one QTL in LG1 using third generation backcross progenies, which was validated here in the first generation backcrosses, suggesting that this QTL is operating in various populations of a broad genetic background, making it useful for application in marker-assisted selection.
A presentation as a webinar for the Winn Feline Foundation that focuses on recent findings related to the signatures of selection in the domestic cat genome
BSAVA Manual of Canine and Feline Ultrasonography.pdfLuong Manh
Cuốn sách "Chẩn đoán siêu âm chó và mèo" này được Lương Mạnh chọn lọc từ hàng trăm cuốn sách chẩn đoán hình ảnh thú nhỏ và đánh gia đây là cuốn sách ngắn gọn, dễ học và kiến thức thực tiễn nhất xin được gửi tặng tới mọi người (sách tiếng anh).
Vibriosis is one of the most prevalent fish diseases caused by bacteria belonging the genus Vibrio affecting many marine and fresh water fishes. The disease characterized by septicemia, dermal ulceration, ascitis and haematopiotic necrosis.
Taeniasis is the intestinal infection with adult tapeworms. It is a mild disease, but of significant public health importance as it plays a crucial role in the transmission of cysticercosis, a serious health implication of taeniasis in men. Cysticercosis is the infection with the larval stages (cysticerci) of the tapeworm inside the body, cysticerci can develop in a number of tissues, those that are located in the central nervous system cause neurocysticercosis, the most severe form of this disease. Other health implications of this endemic disease are appendicitis, dizziness, constipation, and diarrhoea. This endemic and neglected tropical disease can be diagnosed by direct faecal smear, brine floatation techniques, cellophane tape technique, biopsy of subcutaneous nodules, x-ray, CT scan or MRI are used to diagnose the brain type of cysticercosis and ophthalmoscope examination for the ocular form. However, there are several treatment options for the disease, ranging from anti-helminthic therapies, surgery and lifestyle modification programmes.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
1. A Pathogen Lurking in the Darkness:
Global Emergence of Ranavirus
in Ectothermic Vertebrates
M. Niemiller
Debra L. Miller1,2 and Matthew J. Gray1
University of Tennessee
1Center for Wildlife Health
2CVM Department of BDS
26 September 2014, 12:00 PM
University of Georgia
2. Outline
I. Ranavirus Characteristics and Die-offs
IIII.. PPaatthhoollooggyy ooff RRaannaavviirruusseess
IIIIII.. LLeeaarrnniinngg aabboouutt RRaannaavviirruuss ((FFVV33)) EEccoollooggyy
IV. Can Ranaviruses Contribute to Declines?
3. Ranavirus Characteristics
•dsDNA, 150-280K bp
•120-300 nm in diameter
(3x smaller than bacteria)
•Icosahedral Shape (20)
Une Balseiro
Family: Iridoviridae
Iridovirus, Chloriridovirus, Ranavirus, Megalocytivirus, Genera: and Lymphocystivirus
Virion
Invertebrates Ectothermic Vertebrates
Chinchar et al. (2011)
Paracrystalline
Array
Species (6)
Ambystoma tigrinum virus (ATV)
Bohle iridovirus (BIV)
Frog virus 3 (FV3)
ICTV (2012)
Epizootic haematopoietic necrosis virus
European catfish virus
Santee-Cooper Ranavirus
4. History of Ranavirus Die-offs
First Isolated: •Dr. Allan Granoff
•St. Jude Hospital
•Rana pipiens (1962)
First Large-scale Die-offs:
•Dr. Andrew Cunningham
•Institute of Zoology, ZSL
•Rana temporaria (1992)
First North American Die-offs:
•Dr. Jim Collins and students
•Arizona State University
•Ambystoma tigrinum stebbinsi (1985, 1997)
A. Duffus
5. Global Distribution of
Ranavirus Cases: Amphibians
Duffus et al. (2015) 6 Continents: 1965, 1992
All Latitudes, All Elevations
Acta Herpetologica
18 Families: Alytidae, Ranidae, Hylidae, Bufonidae, Centrolenidae, Craugastoridae, Dendrobatidae,
Discoglossidae, Leptodactylidae, Pipidae, Myobatrachidae, Rhacophoridae, Scaphiopodidae,
>100 Species Ambystomatidae, Salamandridae, Hynobiidae, Cryptobranchidae
6. Global Distribution of
Ranavirus Cases: Reptiles
4 Continents: 1982, 1990s
Duffus et al. (2015)
Most FV3-like Ranaviruses: Captivity
12 Families: Agamidae, Anguidae, Boidae, Dactyloidae, Emyididae, Gekkonidae,
Iguanidae, Lacertidae, Pythonidae, Testudinidae, Trionychidae, Varanidae >30 Species
7. Global Distribution of
Ranavirus Cases: Fishes
22 Families:
>50 Species
>90% of
Reports Since
4 Continents: 1991
Duffus et al. (2015)
2010
Most non-FV3-like Ranaviruses
Acipenseridae, Anguillidae, Centrarchidae, Channidae, Cobitoidae, Cyprinidae, Eleotridae,
Esocidae, Gadidae, Gasterosteidae, Ictaluridae, Labridae, Latidae, Lutjanidae, Moronidae,
Percidae, Poeciliidae, Salmonidae, Sciaenidae, Scophthalmidae, Serranidae, Siluridae
8. Maine 2013 Die-off
1000 carcasses/m2
>200,000 dead
qPCR Confirmed
6/14/13
Wheelwright et al.
(2014)
<24 hrs
6/15/13
9. Ranaviral Disease in Eastern Box Turtles
13 February
2012
26 of 31 Box
Turtles Die
from
Ranaviral
Disease
Larval
anurans and
salamanders
dead too
Farnsworth
and Seigel,
Towson U.
2008 – 2011
North Branch
Stream Valley
State Park
10. How Does Ranavirus Infect A Host?
Routes of Transmission
Water or
Sediment
Brunner et al. (2004), Harp & Petranka (2006), Brunner et al. (2007), Hoverman et al. (2010), Robert et al.
(2011)
Indirect
Transmission
Skin, Gills,
Intestines
(epithelial cells)
(3 hrs viral
transcription)
Ingestion
Incidental,
Necrophagy,
Cannibalism,
Predation
(Mortality
2X Faster)
Direct
Contact
One Second
Skin Contact
17. BBrraazziill:: 22
pprreesseennttaattiioonnss::
ttaaddppoolleess vvss
aadduullttss
((MMaazzzzoonnii,, iinn pprreepp))
Edema and Hemorrhages
Neurologic:
vestibular syndrome
Hemorrhage and
necrosis
Photos: R. Mazzoni
18. IIss tthhiiss
rraannaavviirraall
ddiisseeaassee iinn
hheellllbbeennddeerrss
?? Ozark hellbender (K. Irwin)
Ozark hellbender (K. Irwin)
It is in
Chinese
Giant
Salamanders!
(Y. Geng)
46. WWhhaatt aabboouutt TTrreeaattmmeenntt??
(Y. G4e6ng)
- Antivirals?
- Temperature?
- Vaccine development (Asia)
- Much focus on fish
ranaviruses (Japan)
- DNA and Live vaccines
- Oral delivery
- In China, an inactivated
vaccine is being studied for
use in Chinese Giant
Salamanders.
48. Ranavirus in TN
Cattle Land Use
0.36
P =0.78 P =0.02
0.4
0.3
3.9X
More
Likely!!!
0.15
0.5
0.4
0.3
0.2
0.1
0
Bullfrog Green Frog
FV3 Prevalence
Cattle Land
Use
Access
Non-access
A
A
A
B
n =104 tadpoles n =80 tadpoles
49. Life History and Phylogeny
Amphibians
P = 0.354
Hoverman et al. (2011);
Brenes (2013)
All Three Isolates
• Fast larval development time*
• Low aquatic index
• Breeding habitat (ephemoral)
No Phylogenetic Signal
35 spp
Physiological Trade-off Hypothesis
Susceptibility:
0 – 100%
1/3 of Species:
>75%
Mortality
50. Single-species FV3-like Challenges
Chelonians
Terrapene carolina, T. ornata, Elseya latisternum, Emydura krefftii , Trachemys scripta
Greatest infection and morbidity with IP
injection or oral inoculation.
Water bath exposure sufficient for transmission
with some species.
Ariel (1997), Johnson et al. (2007), Allender et al. (2013)
Control Turtle Fish Amph
Graptemys
pseudogeographica
kohni
Eastern River Cooter
– no infection
Brenes et al (2014a)
Apalone ferox
51. Single-species FV3-like Challenges
Fishes
Brenes et al. (2014a)
Gambusia affinis
Ictalurus punctatus
Control Turtle Fish Amph Control Turtle Fish Amph
No Transmission: Nile tilapia, bluegill and fathead minnow
Journal of Aquatic Animal Health 26:118-126
52. Reservoirs or Amplification Hosts?
FV3-like Ranaviruses
Low Mortality
(Subclinical)
Suitable Hosts
Low Mortality
(Subclinical)
Low – High Mortality
(Subclinical & Clinical)
Reservoir Reservoir or
Amplification
Reservoir
54. Experiment
• Direct exposure
– Exposed to 103 PFU/mL
– 3 days
• 12-L containers divided in
half by a 2000 μm plastic
mesh
• Different species in each
side of the container
Amphibian: Hyla chrysocelis ; Turtle: Trachemys scripta elegans; Fish: Gambusia affinis
55. Turtle and Fish Results
• All classes tested can
transmit the virus
• Turtles infected tadpoles
– 50% mortality
• Fish infected tadpoles
– 10% mortality
50%
10%
Brenes et al. (2014b)
56. Amphibian Results
Brenes et al. (2014b)
• Amphibians transmitted to turtles
but not fish
• No mortality of turtles or fish
exposed to infected tadpoles
• Suggests that turtles and fish may
be reservoirs of FV3-like ranavirus
• Amphibians may be amplifying
species
57. Community Level Transmission
Brenes, Gray, & Miller (unpubl. data)
Inoculated in Lab
103 PFU/mL FV3
Exposure Order
Appalachian: Wood frog, chorus
frog, spotted salamander
Coastal Plains: Gopher frog, chorus,
southern toad
Does Exposure Order or Composition Matter?
58. SSuuppeerrsspprreeaaddiinngg aanndd AAmmpplliiffiiccaattiioonn
ooff RRaannaavviirruuss
Reilly, Gray, Miller (unpubl. data)
Cope’s gray treefrog
45% of initially exposed
tadpoles.
Nearly 0 transmission of
ranavirus & no mortality.
Wood Frogs
100% of initially exposed
tadpoles became infected.
Transmission to and
mortality of >80% of
unexposed tadpoles.
59. Temperature Dependency
Survival: Brand, Reilly, Chaney et al. (unpubl. data)
10oC RC Isolate
L. sylvaticus
FV3 In Vitro Replication Stops at 12 C (Chinchar 2002)
FV3-like ranaviruses appears to become pathogenic at 12 C
(54 F) but infection in vivo can occur at lower temperatures.
60. Are Ranaviruses
Capable of Causing
Local Extirpations and
Species Declines?
250
200
150
100
50
0
1960
1963
1966
1969
1972
1975
1978
1981
1984
1987
1990
1993
1996
Number of Populations
Collins & Crump
(2009)
Muths et al.
(2006)
61. Evidence of Local Extinction
Dr. Amber Teacher
Southeastern England
Animal
Conservation
13:514-522
1996/97 and 2008
Ranavirus (+)
populations
81% Median
Reduction
A. Teacher
Larger Populations
Teacher et al.
2010
81%
Greatest
Proportional
Declines A. Teacher
Rana temporaria
63. Time to Extinction
Earl and Gray (2014)
Closed Population
25 years
300 years
Exposed Every Year = 5 years
64. Evidence of Rare Species Effects
Sutton et al. (accepted)
Endangered Dusky Gopher Frog
Diseases of Aquatic
Organisms
n = 18 /trt
ADULTS
Water bath
(103 PFU/mL)
Lithobates sevosus
65. Evidence of Rare Species Effects
Chaney et al. (in progress)
Endangered Dusky Gopher Frog
66. Ranavirus and
Small/Isolated Populations
Rana latastei
Isolated Populations
Pearman and Garner (2005)
Isolated Populations had Faster Mortality and Less Genetic Diversity
67. Factors Contributing to Emergence
Anthropogenic Stressors:
1) Herbicide (Atrazine)
Forson & Storfer (2006); Gray et al. (2007); Greer et
al. (2008); Kerby et al. (2011)
A. tigrinum ATV Susceptibility
Insecticide (Carbaryl)
2) Cattle Land Use: Prevalence Green Frogs and Tiger
Salamanders
Other Possible Stressors: Pesticide Mixtures, Nitrogenous Waste,
Endocrine Disruptors, Acidification, Climate Change, Heavy Metals
Pathogen Pollution:
(Cunningham et al. 2003)
Anthropogenic introduction of novel strains to naïve populations
•Fishing Bait
•Ranaculture Facilities
•Biological Supply Companies
•International Food & Pet Trade
Picco et al. (2007) •Contaminated Fomites Schloegel et al. (2009)
68. Should we be concerned?
•Ranavirus are Multi-species Pathogens
•Amphibians with fast-developing larvae most susceptible
•Isolated populations (rare species) greatest threat
•Interclass Transmission can occur
•Community Composition matters
•Transmission is efficient – Multiple Routes
•Environmental Persistence is long (1 – 3 mo)
•Anthropogenic Stressors and Pathogen Pollution
contribute to Ranavirus Emergence
Ranaviruses represent a significant threat to the
global biodiveristy of ectothermic vertebrates
69. What can we do?
•Establish surveillance programs
(broad then focus on hotspots, >40% infection)
•Identify mechanisms of emergence
(natural, stressors, novel strains)
•Identify and implement intervention strategies
(break host-pathogen cycle, reduce stressors,
biosecurity precautions)
Gray and
Miller (2013)
70. World Organization for Animal Health
OIE Aquatic Code International
Chytridiomycosis
Ranaviral disease
2008
Transport of
Animals
Certification for
Shipment
•Bleach >4%
•EtOH >70%
•Virkon >1%
•Nolvasan >0.75%
$75/
bottle
Notifiable Diseases
Schloegel et al. (2010)
Disinfection: Johnson et al. (2003), Bryan et al. (2009),
Gold et al. (2013)
71. Global Ranavirus Consortium
http://fwf.ag.utk.edu/mgray/ranavirus/ranavirus.htm
Symposia
Discussion Groups
Website
Reporting System
Outreach Resources
Springer eBook
The goal of the GRC is to facilitate communication
and collaboration among scientists and veterinarians
conducting research on ranaviruses and diagnosing
cases of ranaviral disease
GRC@LISTSERV.UTK.EDU
72. Third International
Symposium on Ranaviruses
2015 Florida Marine Health Conference
30 May – 1 June 2015 (3 days): Gainesville, FL
Dr. Tom Waltzek
Invited Talks and Poster Session
Directed Topic Discussions
Workshops
Field Trips
73. Presentation
Contributors:
A. Balseiro, SERIDA
M. Brand, University of Tennessee
R. Brenes, Carroll University
J. Chaney, University of Tennessee
A. Duffus, Gordon College
R. Goodman, Hampden-Sydney College
R. Hardman, Laboklin GmbH & Co KG
R. Hill, University of Tennessee
J. Hoverman, Purdue University
A. Kouba, Memphis Zoo
J. Lankton, USGS NWHC
R. Mazzoni, Universidade Federal de Goiás
D. McGinnity, Nashville Zoo
P. Reilly, University of Tennessee
M. Ruder, USDA
S. Schlosshan, UT Histology (CVM)
B. Sutton, Tennessee State University
T. Waltzek, University of Florida
B. Wilkes, UT Virology (CVM)
Unpublished Data or
Gratis Service
Degeneration of hepcytes with loss of membrane integrity
Widespread pyknosis and karyorrhexis (Hematopoietic and sinusoidal endothelial cell)
Low power kidney
So what is contributing to this vast difference in pathogen transmission between these two species. One of the most notable piece of data we need to look at is the fact that 100% of the initially exposed wood frog tadpoles became infected, which in return lead to the transmission to and mortality of greater than 70% of the unexposed tadpoles. By comparison, only 45% of the initially exposed Cope’s gray treefrog tadpoles became infect, which resulted in nearly 0 transmission of and no mortality due to ranavirus. In fact, it has been documented that certain host characteristics( such as shedding rates, contact rates, and host susceptibility) are major contributing factors to pathogen transmission. The last of which we just showed to potentially play a huge role in ranavirus transmission.
