The secret of the bat genome Emma Teeling

what I want you all to do right now is

to think of this mammal that I’m going

to describe to you the first thing I’m

going to tell you about this mammal is

that it is essential for our ecosystems

to function correctly if we remove this

mammal from our ecosystems they simply

will not work that’s the first thing the

second thing is that due to the unique

sensory abilities of this mammal if we

study this mammal we’re going to get

great insight into our diseases of the

senses such as blindness and deafness

and the third really intriguing aspect

of this mammal is that I fully believe

that the secret of everlasting youth

lies deep within its DNA so are you all

thinking so magnificent creature isn’t

it

who here thought of a bat I can see half

the audience agrees with me and I have a

lot of work to do to convince the rest

of you so I have had the good fortune

for the past 20 years to study these

fascinating and beautiful mammals

one-fifth of all living mammals is a bat

and they have very unique attributes

bats as we know them have been around on

this planet for about 64 million years

one of the most unique things that bats

do as a mammal is that they fly now

flight is an inherently difficult thing

flight within vertebrates has only

involved three times once in the bat

once in the bird and once in the

pterodactyls and so with flight it’s

very metabolically costly bat have

learned and evolved how to deal with

this but one other extremely unique

thing about bats is that they are able

to use sound to perceive their

environment they

use echolocation now what I mean by

echolocation the emitter sound from

their larynx out to their mouth or

through their nose this sound wave comes

out and it reflects and echoes back of

objects in their environment and the

bats then hear these echoes and they

turn this information into an acoustic

image and this enables them to orient in

complete darkness indeed they do look

very strange we’re humans we are visual

species when scientists first realized

that bats are actually using sound to be

able to fly in orient and move at night

we didn’t believe it for a hundred years

despite evidence to show that this is

what they were doing we didn’t believe

it now if you look at this bat it looks

a little bit alien indeed the very

famous philosopher Thomas Nagel once

said to truly experience an alien life

form on this planet you should lock

yourself inside a room with flying at

locating bat in complete darkness and if

you look at the actual physical

characteristics on the face of this

beautiful horseshoe bat you see a lot of

these characteristics are dedicated to

be able to make sound and perceive it

very big ears strange nose leaves but

teeny tiny eyes so again if you just

look at this bat you realize sound is

very important for its survival most

bats look like the previous one however

there are a group that do not use

echolocation they do not perceive their

environments using sound and these are

the flying foxes if anybody has ever

been lucky enough to be in Australia

you’ve seen them coming out of the

Botanic Gardens in Sydney and if you

just look at their face you can see

they’ve much much larger eyes and much

smaller ears so among and within bats is

a huge variation in their ability to use

sensory perception now this is going to

be important for what I’m going to tell

you later during the talk now if the

idea of bats in your belfry terrifies

you and I know some people probably

are feeling a little sick looking at

very large images of bats that’s

probably not that surprising because

here in Western culture bats have been

demonized really of course the famous

book Dracula written by a fellow

Northside Dubliner Bram Stoker probably

is mainly responsible for this however I

also think it’s got to do with the fact

that bats come out at night and we don’t

really understand them were a little

frightened by things I can perceive the

world slightly differently than us bats

are usually synonymous from some type of

evil events they are the perpetrators in

horror movies such as this famous

Nightwing also if you think about it

demons always have bat wings whereas

bird they typically or angels have bird

wings now this is Western society and

what I hope to do tonight is to convince

you of the Chinese traditional culture

that they perceive bats as creatures

that bring good luck

and indeed if you walk into a Chinese

home you may see an image such as this

this is considered the five blessings

the Chinese word for bat sounds like the

Chinese word for happiness and they

believe that bats bring wealth health

longevity virtue and serenity and indeed

in this image you have a picture of

longevity surrounded by five bats and

what I want to do tonight is to talk to

you and to show you that at least three

of these blessings are definitely

represented by a bat and that if we

study bats we will get nearer to getting

each of these blessings so well how can

a bat possibly bring us wealth and as I

said before bats are essential for our

ecosystems to function correctly and why

is this bats in the tropics are major

pollinators of many plants they also

feed on fruit and they disperse the

seeds of these fruits bats are

responsible for pollinating the tequila

plant and this is a multi-million dollar

industry in Mexico so indeed we need

them for our ecosystems to function

properly

without them it’s going to be a problem

but most bats are ferocious insect

predators it’s been estimated in the US

and a tiny colony of big brown rats that

they will feed on over a million insects

a year and in the United States of

America right now bats have been

threatened by disease known as white

nose syndrome it’s working its way

slowly across the u.s. and wiping out

populations of bats and scientists have

estimated that 1300 metric tons of

insects a year are now remaining in the

ecosystems due to the loss of bats bats

are also threatened in the u.s. by their

attraction to wind farms again right now

batter looking a little bit of problem

they’re going to there they are very

threatened in the United States of

America alone now how can this help us

well it has been calculated that if we

were to remove bats from the equation

we’re going to have to then use

insecticides to remove all those pest

insects that feed on our agricultural

crops and for one year in the US alone

it’s estimated it’s going to cost 22

billion US dollars

if we remove bats so indeed bats then do

bring us wealth they maintain the health

of our ecosystems and also they save us

money so again that’s the first blessing

bats are important for our ecosystems

and what about the second what about

health inside every cell in your body

lies your genome your genome is made up

of your DNA your DNA codes for proteins

that enable you to function and interact

and be as you are now since the new

advancements in modern molecular

technologies it is now possible for us

to sequence our own genome in a very

rapid time and a very very reduced cost

now when we’ve been doing this we

realize that there’s variations within

our genome so I want you to look at the

person beside you let’s have a quick

look and what we need to realize is that

every 300 base pairs in your DNA you’re

a little bit

and one of the grand challenges right

now in modern molecular medicine is to

work out whether this variation makes

you more susceptible to diseases or does

this variation just make you different

again what does it mean here what does

this variation actually mean so if we

are to capitalize on all of this new

molecular data and personalized genomic

information that is coming online that

we will be able to have for the next few

years we have to be able to

differentiate between the two so how do

we do this

well I believe we just look at nature’s

experiments so through natural selection

over time mutations variations that

disrupt the function of a protein will

not be tolerated over time evolution

acts as a sieve it SIVs out the bad

variation and so therefore if you look

at the same region of a genome in many

mammals that have been evolutionary

distant from each other and are also

ecologically divergent you will be a

better understanding of what the

evolutionary prior of that site is ie if

it is important for the mammal to

function for survival it will be the

same in all of those different lineages

species taxa so therefore if we were to

do this want me to do with sequence that

region in all these different mammals

and ascertain if it’s the same or if

it’s different so if it is the same this

indicates that that site is important

for function so a disease mutation

should fall within that site so in this

case here if all the mammals that we

look have have a yellow type genome at

that site it probably suggests that

purple is bad this could be even more

powerful if you look at mammals they’re

doing things slightly differently so say

for example the region of the genome

that I was looking at was a region

that’s important for vision if we look

at that region in mammals that don’t see

so well such as bats and we find that

backs that don’t see so well have the

purple type we know that this is

probably what’s causing this disease

so in my lab we’ve been using bats to

look at two different types of diseases

of his other senses we’re looking at

blindness and why would you do this

340 million people are visually impaired

and 45 million of these are blind so

blind us is a big problem and a lot of

these blind disorders come from

inherited diseases so we want to try and

better understand which mutations in the

gene causes the disease also we look at

deafness one in every 1,000 newborn

babies are deaf and when we reach 80

over half of us will also have a hearing

problem again there’s many underlying

genetic causes for this so what we’ve

been doing in my lab is looking at these

unique sensory specialists the bats and

we have looked at genes or cause

blindness when there’s a defect in them

jeans are cause deafness when there’s a

defect in them and now we can predict

which sites are most likely to cause

disease so bats are also important for

our health to enable us better

understand how our genome functions so

this is where we are right now but what

about the future

what about longevity this is where we’re

going to go and as I said before I

really believe that the secret of

everlasting youth lies within the bat

genome so why should we be interested in

aging at all but really this is the

picture drawn from the 1500s of the

Fountain of Youth

aging is considered one of the most

familiar yet the least well understood

aspects of all of biology and really

since the dawn of civilization mankind

has sought to avoid it but we are going

to have to understand it a bit better in

Europe alone by 2050 there’s going to be

a 70% increase of individuals over 65

and 170 percent increase in individuals

over 80 as we age we deteriorate and

this deterioration causes problems for

the society so we have to address it so

how could the secret of everlasting

youth actually lie within the bat genome

does anybody

hazard a gasps over how long this bat

could live for who put up your hands who

says two years nobody won

how about ten years some how about 30

how about 40 okay it’s a whole varied

response this bat is my Otis Bronte I

it’s the longest living bat it lives for

up to 42 years and this bat still alive

in the wild today but what would be so

amazing about this well typically in

mammals there is a relationship between

body size metabolic rate and how long

you can live for and you can predict how

long a mammal can live for given its

body size so typically small mammals

live fast die young think of a maze but

bats are very different as you can see

here on this graph in blue these are all

other mammals but bats can live up to

nine times longer than expected despite

having a really really high metabolic

rate and the question is how can they do

that

there are 19 species of mammal that live

longer than expected given their body

size than man and 18 of those are bats

so therefore they must have something

within their DNA that Able’s them deal

with the metabolic stresses particularly

of flight

they expand 3 times more energy the

mammal of the same size but don’t seem

to suffer the consequences or the

effects so right now in my lab we’re

combining state-of-the-art back field

biology go ahead and catching the

long-lived bats with the most up-to-date

modern molecular technology to

understand better what it is that they

do to stop aging as we do and hopefully

in the next five years I’ll be giving

you a TED talk on that aging is a big

problem for Humanity and I believe that

by studying bats we can uncover the

molecular mechanisms that enable mammals

achieve extraordinary on cavity if we

find out what they’re doing

perhaps through gene therapy we can

enable us to do the same thing

potentially this means that we could

halt aging or maybe even reverse it

and just imagine what that would be like

so really I don’t think we should be

thinking them it’s flying demons of the

night but more as our superheroes and

the reality that bats can bring us so

much benefits if we just look in the

right place they’re good for our

ecosystem they allow us understand how

our genome functions and they

potentially hold the secret to

everlasting youth so tonight when you

walk out of here and you look up in the

night skies and you see this beautiful

flying mammal I want you to smile thank

you