Jurassic World: Can geneticists really resurrect dead species?

The filmmakers behind Jurassic World have updated the franchise’s plot line, with scientists creating a new genetically enhanced dinosaur that (predictably) goes on a rampage. In the 22 years since the original Jurassic Park movie, genetic engineering has come a long way, leading some scientists to suggest that the fictional science might be actually be possible. We asked animal biotechnology experts to comment on whether the idea of bringing back and genetically engineering prehistoric species is grounded in reality.

 

Dr. Mark Westhusin, Professor, Department of Veterinary Medicine and Biomedical Sciences, Texas A&M University (webpage): 

Expertise: developmental biology, cloning animals by nuclear transplantation, genetic engineering in animals,assisted reproductive techniques, epigenetics and control of gene expression

“As my undergrad teacher, Dr. Farmer, stated each semester at the beginning of his class when teaching basic reproduction, “there is no production without reproduction.” Unfortunately, too many of those who are playing around with genes in a test tube or cells growing in culture have the misconception that going from a test tube or petri dish to an entire living breathing animal is a ‘walk in the Jurassic Park’, when in fact it is by far and away the major obstacle when the goal is to produce an actual living animal.

“The idea that genetic engineering could get round the difficulties of bringing back creatures from prehistory is a classic example of ignoring the most important part of the entire process, which boils down to basic reproduction. We probably could genetically modify a dinosaur, but in order to do so we would still have to have a dinosaur we brought back first! We could perhaps put a few dino genes in a chicken or a lizard or some other species, but we would not get a dinosaur. We would simply get something that looked like a chicken but with a few traits modified.

“As an example, George Church’s group in Harvard recently got a ton of press for using the hot new CRISPR/Cas system to splice some gene sequences from a woolly mammoth into cells from an elephant that were growing in culture. Cells growing in culture in an incubator are a long way from a whole animal walking around, breathing, eating, reproducing, etc. If we wanted to produce a whole animal then we would have to use cloning, a task people often take for granted as easy since we have cloned so many different animals nowadays.

“Cloning, even when it works, is still very inefficient and often requires hundreds of cloned embryos to be successful. If you were to clone a mammoth and use an elephant as the surrogate mother for gestation of the embryos, where would you get the elephant eggs to use for the nuclear transfer? Where would you get enough female elephants to donate eggs and put the cloned embryos in? At what stage of the reproductive cycle would you transfer them? Etc. etc. etc…

“We can clone and obtain genetic modification in a number of different mammalian species now, but only because we have spent hundreds of years and countless dollars to study and understand the basics of reproduction. We know a tremendous amount about reproduction in some species, but when you jump to a new species, even basic techniques like artificial insemination can take you back to square one.”

 

Dr. Alison Van Eenennaam, Animal Geneticist in the Department of Animal Science at the University of California, Davis (webpage):

Expertise: research and education on the use of animal genomics and biotechnology in livestock production system; use of DNA-based biotechnologies in beef cattle production.

“It is true that with conventional breeding we have made incredible changes in our domesticated animal species – both food producing animals and pets. Chihuahuas exist because breeders repeatedly selected dogs with the desired appearance to be parents of the next generation and over hundreds of years developed the breed. This ‘selective breeding’ uses sexually compatible animals to produce the next generation and we can make crossbreds such as a mule which is a cross between a donkey and a horse – but only because the two species are sexually compatible (although the mule itself is sterile). But we cannot cross a dog and a cat. Period.

“Beyond conventional breeding, it is relatively simple to introduce a single trait into some animals, like the fluorescent protein gene into GloFish. There, we know the gene and what is does (i.e. it glows!), and we can introduce that into the GloFish genome. That is a far cry from creating a dinosaur from bits of degraded DNA and a potpourri of genes from other species! We just do not have the biological understanding nor technical skills to successfully perform such genetic acrobatics.

“And unlike in the movies, we have not seen unintended effects in real life animal biotech because we know exactly what gene we have introduced and what that gene does. We have genetically engineered goats at UC Davis that produce a transgenic protein called lysozyme in their milk. Other than that they look, sound and behave like a goat. No unintended effects have been observed in these goats over the past decade or so – except they are less likely to get mastitis (inflammation of the udder) and they produce healthier offspring as a result of the health benefits resulting from the lysozyme in their milk.

“There are some real world attempts to “de-extinct” creatures – for example a group called, Revive & Restore is trying to recreate the passenger pigeon. Their flagship de-extinction project, The Great Passenger Pigeon Comeback, plans to use CRISPR based genome editing to engineer passenger pigeon genes into living band-tailed pigeons, the species’ closest extant relative.

“Even this seemingly ‘simple’ project will be incredibly difficult as there are likely to be hundreds of thousands of sequence differences between these two species, and we just do not have the biological understanding of which ones are required to recreate the passenger pigeon as a species. Let alone the fact that making hundreds or thousands of targeted base pair changes in a genome would be technically challenging! In my laboratory we get excited if we successfully achieve a single targeted base pair change.

“And let’s not forget there is a reason species go extinct – and that is typically because their habitat no longer exists – perhaps preserving habitat is the best way to prevent the extinction of extant species, rather than trying to bring extinct species back from the dead.”

 

Dr. Jason W. Ross, Associate Professor, Department of Animal Science, Iowa State University (webpage): 

Expertise: swine reporoduction and epigenetics, puberty and seasonal infertility in pigs, use of pigs as animal models for disease and physiology. Dr Ross is the Director of the Animal Gene Transfer Facility at Iowa State University

“The ability to make specific genetic modifications to animals is becoming increasingly efficient with improved precision. Numerous methods to create transgenic animals have continued to be improved and optimized since development of some of the first transgenic mice in the early 1980’s. Typically, traits that are under the control of a specific gene are the most commonly engineered into animal genomes. For example, the utilization of the gene from jellyfish coding the protein sequence for green fluorescent protein enables cells in animals to also fluoresce when expressing that protein as a result of the genetic inclusion. However, while the transgenic animal may express the trait encoded by the GFP gene by fluorescing, they are not capable of taking on additional characteristics of the species that provided the genetic information, beyond what that single gene encodes. While opportunities for unintended modification to a host genome can occur during genetic modification of a genome, modern DNA sequencing technologies would enable the ability to pin-point those ‘errors’ and enable site specific correction or the avoidance of using those cell lines.

“While creating an animal that has multiple traits from different species might be feasible in the mind’s eye, it is quite beyond what is scientifically or technically feasible, at least to the point that is portrayed in Jurassic World. Effectively “merging” the genetic information from multiple species into one would require the restructuring of an entire genome to represent a compatible arrangement of genes and the chromosomes in which they are housed. While this may be theoretically possible from a genetic engineering standpoint, to be technically feasible this genetically novel cell line would need to be developed into an animal through nuclear transfer which is not a trivial task.

“Nuclear transfer is the primary method of cloning that would have any potential to ‘de-extinct’ a creature. However, this method requires the resource of an egg from a genetically similar animal to enable the cloning process. To truly ‘de-extinct’ an animal would require that eggs for that animal are available and amenable to enucleation and nuclear transfer. Using an egg source from a related animal may be feasible although the mitochondrial genome present in the recipient egg would be genetically unique in comparison to the mitochondrial genome of the nuclear donor cell or the extinct creature. Furthermore, it requires that genome of the donor cell line coming from an extinct animal be intact and capable of supporting development, a rapidly decreasing likelihood for animals that have gone extinct prior to the very recent past.”

 

Declared interests (see GENeS register of interests policy):

No interests declared

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