TEARS OF THE CHEETAH - a story of genetic diversity

Dr Karobi Moitra , NCI Frederick

Where do cheetahs stand on the tree of life?Kingdom: Animalia

Phylum : Chordata

Class : Mammalia

Order : CarnivoraFamily : FelidaeGenus: AcinonyxSpecies: A. jubatus

Order : PrimatesFamily : HominidaeGenus : HomoSpecies: H. sapiens

Where did the name ‘cheetah’ come from ?

Sanskrit word : Chitakayah- which means ‘variegated’ body - ‘marks or patches’’

Hindi - ‘Chitah’ English : Cheetah

Cheetah range :

Africa: Niger,Sudan, Ethiopia,Kenya,Tanzania,Namibia,Botswanaetc.

Iran: Khorasan

SE Asia: India?Pakistan?

Some cool cheetah facts :• Cheetah eat gazelles, impala, zebra, hare etc.

• They hunt in early morning or late in the afternoon

• They hunt in groups

• Rely on vision not scent to hunt

• Adult cheetahs weigh ~ 140lb

• Total body length over 6ft

• Have a distinct ‘tear’ streak

How fast can cheetah’s run ? Cheetah’s can run upto 75 mph (120km/h)for 1,500ft or 1min 30 secs.

Acceleration: 1-64 mph in 3 secs

Cheetah Chatter

The African cheetah population was down to around 15,000wild cheetahs

So conservationalists tried to breed them in captivity - thiswas very hard to do

Also cheetah populations were very prone to disease, if afew cheetah were infected with a disease such as FIPV-feline infectious peritonitis virus, the rest become infectedand die

WHY?

Journey to Africa

Mitch Bush (National Zoo) & David Wildt (NCI)boarded a plane to the DeWildt cheetah breedingcenter in Pretoria (South Africa)

They collected blood samples from around 80 cheetahsand brought them back to Stephen O’Briens lab at NCI-Frederick for analysis.

Proteins in the cheetahs blood wereseparated and analyzed using a techniquecalled :

Protein Gel Electrophoresis

Protein Gel Electrophoresis

Mobility shifts (change in the position of a protein band)can identify the different types of enzyme variantsin a cheetah blood sample

Most animals have a 20-50% difference in specific blood proteins(enzymes) called allozymes because they are different varieties of the same protein

However, when Janice Martenson looked at the allozymesIn the cheetah blood samples she found that cheetahs were Identical for 52 allozymes across the board.

What did this mean?

Cheetahs seemed to be almost genetic clones ofeach other….but more evidence was needed !

DNA

RNA PROTEIN

The double helix

Genetic diversity

Back to Africa !

MHC genes are extremely variable

They are responsible for graft rejection

Skin grafts from 6 unrelated cheetahs were done

If these graft were accepted and grew it meant that these cheetahs were nearly genetically identical to each other = very little genetic diversity

All 6 cheetahs accepted the grafts

Most cheetahs are almost identical clones of each other !

That is why they are more susceptible to disease !

How did this happen?

The “Bottleneck Effect”

12,000yaPleistoceneGreat mammalExtinction

Tears of the cheetah - the legend“A young female cheetah climbed into a warm caveto slumber through a harsh winter in Europe. When she and her cubs crept out in springtime, they meta different world, one in which the cheetahs were (almost)gone - victims of a global holocaust”

……and she cried for them

http://www.cheetahkids.com/

Save the cheetah !

References / Websites

www.wikipedia.org

www.cheetah.org

www.cheetahkids.com/

Tears of the Cheetah by Stephen J . O’Brien