Genomes-L16- De-extinction

instances of animal cloning done

1996- dolly the sheel

2003- Ralph the male rat

2021- Elizabeth ann- black footed ferret

discuss Dolly

• sheep 1 is cloned and has a white face- cultured these cells

• take sheep 2- egg- with a black face and took away nucleus

• sheep 1 nucleus into sheep 2- egg is identical to sheep 1!!

how would we clone a brochisaurus? why isn’t it possible?

• using fossils- to extract amber BUT!!

• fossils are rocks- not organic material

• DNA degrades, gut and soil bacteria will degrade organisms

• DNA repair no longer intact

• UV radiation etc

• DNA half life in 521 years

• impossible!!

how would we clone a mammoth?

DNA is still present

1. get mammoth tooth DNA

2. extract DNA mammoth(this was done!)

3. get mammoth genome- we don’t have the FULL!!! genome though 18% of It is unknown

4. put the genome in a cell- not possible as we cant make chromosomes and put them in a nucleus!

5. put egg in surrogate mother

6. put mammoth back in the ecosystem

why cant we get entire mammoth genome? what step is this?

step 3- we cant as DNA is not well preserved

• as DNA is short and damaged

• few organisms have full genome sequenced as repetitive regions are hard to!

how do we even know the mammoth DNA is actually mammoth DNA?

used the sequenced Asian elephant to identify DNA fragments that likely belong to the mammoth

• looking at differences- mutations that make them different

• or looking at partial matches

• hard to map up mammoth DNA to elephants as there could have been deletions or insetions

why cant we put genome in a living cell? what step is this?

step 4

• we cannot construct chromosomes as they’re DNA packed around histones

• 8 histone porteins around DNA- nucleosomes- to make chromtin

• even if we could make chromosomes- how do we get them into a nucleus of a living cell?

• not possible!

plan B: engineering a mammoth using CRISPR

if a mammoth is 99% elephant we could swap the missing 1%

• use CRISPR to cut and paste mammoth genes in

what genes would we target if we were to engineer a mammoth?

• genes for hair and skin- TRPV3

• difference in storage and metabolism

• difference in genes for temerpature sensation

• difference in circadian clock- mammoths deal with dark winters and light summers

• hemoglobin genes- more effective at providing O2 is cold temps

issues with a surrogate mother

• size differences and weight would be an issue

• differences in environment would be different- also changes in hormones, diet and microbiota

• if mammoth were to be bron- would learn behaviour from an elephant- not natural!!

couldn't use nuclear transfer and artifical womb may be needed!

issues with putting the “mammoth” back in the environment?

changes in the environment since it went extinct

• other species may have taken over its role in the environment

• is it ethical? things could go wrong

• what effect would it have? ie - - in Australia rabbits destroyed gross and led to land erosion and decline of native animals and plants

how would a mammoth also benefit the environment?

break snow on soil and low the temperature and refreeze permafrost

• makes more photosynthesis in grass and reflect more sunlight

ethics of cloning?

1. efficacy of cloning is extremely low

2. abnormalities in cloned animals- obesity etc

3. keeping animals in captivity such as elephants show strange behaviour

4. if they went extinct- would they even be able to survive now

5. risk to suurogates

6. negative impact on ecosystem

7. very expensive

how would you engineer a mammoth?

1. get the mammoth gene

2. identify the differences

3. edit the elephant cells wit CRISPR

4. clone the edited cell

5. place in surogate mother

6. place mammophant into the ecosystem