L8 De-Extinction

Question 1

What is the shelf life of DNA?

Answer 1

More than 800,000 years

Question 2

What is De-extinction?

Answer 2

-Creating an organism which is either a member of or resembles an extinct species
-Term applies to a variety of molecular biology techniques that represent new research in conservation biology
-Controversial topic

Question 3

Can ancient DNA be extracted?

Answer 3

-Yes, from fossils, frozen carcasses
-However DNA becomes fragmented over time
-Not usually able to sequence a full genome
-Gaps have to be filled from closely related species

Question 4

What is an allele?

Answer 4

Is a variant form of a gene

Question 5

How many tissue samples are in the Frozen Zoo in San Diego Zoo?

Answer 5

1000 tissues from species
-Stored at -196 degrees

Question 6

What does iPS stand for?

Answer 6

Induced Pluripotent Stem Cells

Question 7

What are Pluripotent stem cells?

Answer 7

Is a cell that can differentiate into all specialised cells like ectoderms, endoderm and mesoderm

Question 8

What is an iPS?

Answer 8

Is a type of pluripotent stem cell that can be generated from adult cells

Question 9

What is back-breeding?

Answer 9

-Traits are identified in closest living relative
-Selectively breed offspring with traits
-Eventually individuals will resemble their extinct ‘cousins’
-Sequencing DNA from extinct species can speed up the process

Question 10

Why should species even be brought back from extinction?

Answer 10

-Ethical reasons, driven to extinction by humans in most cases
-Ecological reasons, recreating extinct ecosystems, providing trophic cascades (Wolf in Yellowstone)

Question 11

Why should extinct organism not be brought back?

Answer 11

-Animal welfare, will they even survive
-Habitat and space
-Limited resources
-Morally irresponsible

Question 12

What was one of first animals that was made de-extinct?

Answer 12

Pyrenean Ibex (Bucardo)
-Last individual died in January 2000 in the wild

Question 13

Was the de-extinction of the Pyrenean Ibex successful?

Answer 13

-Cryopreserved DNA used to create a clone
-285 embryos reconstructed
-Only one was carried to term
-Malformed lung, died after 10 mins

Question 14

What ecological concerns would restrict de-extinction?

Answer 14

-Effects are difficult to predict (May not literally be same species, different DNA)
-Lack of habitat for species
-Many species have been driven to extinction by habitat destruction
-Potential invasive nature of species
-Potential vector for disease, could be reservoirs for extinct diseases

Question 15

What are potential conflicts occurring from de-extinction?

Answer 15

-If species has been absent for thousands of years, issues will arise
-Land owners, special interest groups view this negatively
-Predators are viewed negatively

Question 16

Describe the passenger pigeon case study.

Answer 16

-Funding from Revive and Restore
-Non-profit organisation
-Flagship project
-Initiated in 2012
-Status currently, genome engineering

Question 17

What is the first step to de-extincting the passenger pigeon?

Answer 17

-Extract and sequence passenger pigeon DNA
-DNA is extracted from toe pad of museum specimens
-Fragmented, but usable
-DNA from 40 birds analysed
-High quality was sequenced in 2013

Question 18

What is the second step to de-extincting the passenger pigeon?

Answer 18

-2015
-Comparing genetic codes between species and identifying differences (Alleles)

Question 19

What is the 3rd step to de-extincting passenger pigeons?

Answer 19

-Current Status
-Reconstructing the genome using DNA from the band tailed pigeon to fill in the blanks

Question 20

What is the 4th step to de-extincting passenger pigeons?

Answer 20

Reconstructed genome will be placed into primordial germ cells of a band-tailed pigeon

Question 21

What is the 5th step to de-extincting passenger pigeons?

Answer 21

Germ cells will be injected into band-tailed pigeon

Question 22

What is the 6th step to de-extincting passenger pigeons?

Answer 22

When those engineered birds mate, chicks would have some passenger pigeon genes

Question 23

What is the timeline for the passenger pigeon project?

Answer 23

-Captive breeding in 2022
-Soft Release 2027
-Release into the wild 2032