Global amphibian declines

Question 1

how many species of amphibians

Answer 1

5,700

Question 2

since 1980 how many amphibian species have experienced rapid decline

Answer 2

1/3rd

Question 3

nearly 2,000 species

Answer 3

–> that have gone completely extinct

–>gone extinct in the wild but have captive breeding programs at zoos

–> have potentially gone extinct

Question 4

massive extinctions being called

Answer 4

the most spectacular loss of vertebrate biodiversity in recorded history

Question 5

name a disease which is causing an amphibian scourge

Answer 5

Batrachochytrium dendrobatidis

Question 6

Bd is a

Answer 6

chytrid fungus

• aquatic and motile
• causes severe disease in amphibians

Question 7

over the past 30 years

Answer 7

lots of research has poured into research regarding the amphibian scourge

Question 8

in 1997 some of that research paid off

Answer 8

with the very important discovery of the chytrid fungus, Bd

Question 9

Chytrid fungi are

Answer 9

heterotrophs

Question 10

heterotrophs

Answer 10

sequester carbon from other life sources, not the sun–> saphorhphytes and parasites

Question 11

Bd life cycle

Answer 11

1) bd starts as a tiny zoospore that swims in open water
2) when it find suitable host, it burrow deep into the skin and develops into a thallus
3) thallus matures into a sporangium- egg-sac
4) the sporangium grow until they burst open and new zoospores are released
5) these zoospores swim around and find new hosts, or re-infect the same host and cause chronic disease

Question 12

Bd life cycle take

Answer 12

4-5 days

Question 13

Bd causes a chronic skin disease called

Answer 13

chytridiomycosis- colonised keratinised skin layer

Question 14

hyperplasia and hyperkeratosis causes

Answer 14

disrupted electorylye balance

Question 15

chyridiomycosis leads to

Answer 15

cardiac arrest and death due to disrupted electolye dance

Question 16

amphibian ski is

Answer 16

tremendously improtnant

Question 17

amphibians use their skin to

Answer 17

drink- rarely drink through mouths- especially when underwater

Question 18

chytrdiomycosis

Answer 18

chronic infection causes skin to thicken and scar- dehydrating the amphibian leading to their death

Question 19

Bd infected populations can

Answer 19

crash within just a few short months- before anyone knowns the population has become infected

Question 20

chytrdiomycosis is not

Answer 20

easy to diagnose due to no hallmark symptoms

Question 21

two main methods for diagnosing Bd infection are quantitative …

Answer 21

qPCR and histology

Question 22

qPCR requires

Answer 22

an amphibian wiped down with a swab and that swab being sent away to a diagnostic lab
–> CANNOT BE DONE ONSITE

Question 23

downside to qPCR

Answer 23

• cannot be done onsite
• need trained staff
• expensive equipment (>£10,000)
• expensive reagents

£40 per test

• by the time you have the result, frog has been set free- cannot reat

Question 24

alternative to qPCR

Answer 24

histological examinaiiton

Question 25

histological examination

Answer 25

microscopic examination of skin

Question 26

downside of histological examination

Answer 26

requires extensive knowledge of infected and uninfected skin morphologies and requires you take an actual skin sample from the frog - usually have to take from dead amphibian

Question 27

its providing

Answer 27

extremely difficult to monitor BD infections in real time

Question 28

which monoclonal antibody has been chosen to act as an immunotherapy for Bd

Answer 28

mAb 5CO4

Question 29

benefits of mAb5CO4

Answer 29

- grows quickly - produces lots of antibody - very robust - does not require supplementation to grow well

Question 30

next it became important to know where the antigen(glycoprotein/ carbohydrate) to mAb 5C4 was located.. inside? outside? Zoospores? Sporangium? how did they do this

Answer 30

using immunofluorescence- found to be on outside of spores

Question 31

name a better way to diagnose Bd- to help tracking and prevention of disease

Answer 31

lateral flow assay

Question 32

what must a test be to track Bd

Answer 32

- it must be inexpensive and widely used - rapid - immediate results - easy to use

Question 33

how to LFA work

Answer 33

a small amount of liquid is placed on the sample pad and capillary action pulls the fluid across the membrane where it encounters: - a test line- this only appears if you are infected - a control line: always appears- ensures test ran completion

Question 34

which antibodies are used in LFA

Answer 34

labeled and immobilised 5C4 Ab

Question 35

if the antigen is present in the sample (e.g. the frog has the disease)

Answer 35

then the antigens bind to the labeled (gold) 5C4Ab and then binds to the immobilised 5C4 Ab antibody (test line)

Question 36

if the antigen is not present the labeled 5C4 Ab will bind to

Answer 36

the control line label antigens

Question 37

OID can be used to study

Answer 37

antibody-antigen interactions and to determine whether proteins share antigenic determinants

Question 38

IF and EM-gold can be used to

Answer 38

visualise the extracellular and intracellular location of antigens or antibodies in the cell

Question 39

western blotting can be used to

Answer 39

identify individual antigens in a mixture of proteins

Question 40

Lateral flow assays are

Answer 40

semi-quantitiaitev point of care tests