Science in Film: Gattaca Part I
Genetic Engineering, Persistence, Deceit, Space Exploration, and Love
This film opens artistically, with credits rolling over a blue background, the letters A, T, C, and G subtly highlighted in each credit line, set to the at once visionary and emotional musical number “The Morrow” by Michael Nyman. It takes a few moments to realize the blue background is littered with falling hair, cuticles, and flakes of skin, as Jerome Marrow scrubs down his entire body before a day’s work. Jerome lives in a world where his very identity (as we find out latter, that identity is a stolen one) could crumble upon genetic testing by authorities of a misplaced eyelash. He goes about his day at the Gattaca Space Center, set in the beautifully modern architecture of Frank Lloyd Wright’s Marin Civic Center. Obviously trying to appear stoic and unimpressed by his elite status at the prestigious space center and by his central position in an upcoming mission, something seems incomplete about the picture, as Jerome stands looking up through the glass ceiling of the Gattaca building, watching, gleary-eyed, each of the dozen rocket launches of the day.
“The most unremarkable of events: Jerome Marrow, Navigator First class, is only days away from a year-long manned mission to Titan. Of course, selection for Jerome was virtually guaranteed at birth. He is blessed with all the physical and intellectual gifts required for such an arduous undertaking, a genetic quotient second to none.
No, there is truly nothing remarkable about the progress of Jerome Morrow, except that I am not Jerome Morrow.”
Hawke plays Vincent, a young man born without the inference of modern reproductive technologies that incorporate positive genetic selections with in vitro fertilization, interferences that have become the norm for planned births in Gattaca’s view of the ‘not-so-distant’ future. “The child is still you, simply the best version of you”, Vincent’s parents are told by their ‘local" geneticist, when planning for their second son, Vincent’s to-be genetically superior brother Antoine." “You could conceive naturally a thousand times and never get such a result.”
In an era when naturally born ‘in-Valids’ are doomed to the very lowest working class of society, Vincent is not accepting of his fate. He is a naturally born astronomer and an astronaut hopeful… ironically his natural birth and inferior genotypic makeup make his dreams of space exploration a physical impossibility. In an era when, thanks to revolutions in genomic sequencing, his 99% chance of early heart failure results in prejudicing and lack of equal opportunity to insurance coverage and participation in normal activities at school, Vincent is left empty-handed and faced with a life of janitorial work. Vincent’s peak potential in a society of superior genomes, i.e. a position cleaning toilets in the Gattaca space center, is far from his aspiration of reaching the farthest frontiers of space. “We have discrimination down to a science… No matter how hard I study, in the end it makes no difference … my resume is in my cells.” Vincent’s only hope: becoming a ‘borrowed ladder’. Named appropriated, in reference to DNA laddering, his transformation depends on borrowing the genomic identity of a “Valid” member of society, thus securing his acceptance into Gattaca as a member of the genetically elite. Meet Jerome Marrow.
What follows is a tale of human willpower, of surpassing physiological, mental, and social barriers, of meeting and exceeding personal potential, a film of hope and persistence. “Do you know how I did it Antoine? Do you know how?! I never saved anything for the swim back.” But not only does this film strike emotional, ethical, and motivational chords, many aspects of the screenwriting make this film one of the most visionary and realistic movies of the science-based genre. The imagery in the film is also striking: from the spiral staircase in Jerome Marrow’s home, which plays a central role in many of the scenes and camera angles shot in the film, and which structure is reflective of the tortuous spiraling of the DNA helix; the pervading green (symbolic of life and birth – Symbolism in Andrew Niccols “Gattaca” By Jakob Maier) and yellow light filtering; not the mention the very name of the illustrious Space Center, which consists of a 7-base sequence of nucleotides (G-A-T-T-A-C-A) found throughout the human genome. Find below some of the science themes that pervade this film, and current-day realities behind the world of Gattaca.
1. Genetic profiling: “Blood has no nationality”
“The concerns about genetic privacy in the 1990s were largely triggered by the Human Genome Project (HGP ) and the establishment of population biobanks in the following decade. Citizens and lawmakers were worried that genetic information on people, or even subpopulations, could be used to discriminate or stigmatize.” – EMBO Reports Consent to ‘personal’ genomics and privacy
Gattaca, which aired in theaters in 1997, portrays a future where genetic profiling is rampant, and has replaced all other forms of personal identification.
Screening of film characters’ genetic identity are performed automatically and at lightning speed (by the scientific standards of today at implausible speed) via analysis of blood, urine, hair, and other tissue samples. Although the instantaneous result finger-prick genetic identity machine as portrayed in the movie is probably unrealistic on the time-scale required for detection and read-out today, the science behind the testing is very real. The genetic profiling as seen in Gattaca is more realistic in the form of partial DNA analysis, or DNA ‘fingerprinting’, i.e. matching only small but unique regions of an individual’s genome to a database of DNA profiles. Sequencing of an entire genome, i.e. from a single person, can be performed on the time scale of several days with the fastest DNA sequencers of today, still entirely too slow for the instant-result identification screening as seen in Gattaca.
The reality of genetic profiling in today’s world, for the purposes of identification, can be most readily observed on the scene of criminal investigation. Forensics labs use a limited DNA profile as a biometric: a measureable biological characteristic that can be used for automated recognition – FBI. Other biometrics include facial geometry and fingerprint, voice, and iris (muscle of the eye) patterns unique to an individual. National DNA databases exist today, mostly for the genetic profiling of criminal offenders. The FBI has a program for exploring and advancing the use of new and enhanced biometric technologies, called the Biometric Center Of Excellence.
The technique of genetic profiling relies on isolation of genetic material (DNA) from samples such as blood, saliva, hair, or other tissues, and generally amplification of select regions (making more copies of the target DNA region through the polymerase chain reaction, PCR) which are identifiably different from individual to individual. The DNA regions which are used today as genetic ‘fingerprints’ of any given genome are called VNTR areas (variable number tandem repeats). These non-protein coding regions contain varying numbers of repeated sequences, and thus give different sized fragments when the sample DNA is ‘cut up’ into small pieces. Because a technology known as electrophoresis can separate DNA pieces of different sizes, we get a picture of DNA fragments that is different for each separate person tested. However, electrophoresis as a means of separating and detecting the DNA fragments is typically a slow process (on the scale of min-hours), and thus probably not amenable to the frequent and quick identification scans performed in Gattaca. However, newer technologies today that use DNA ‘microarrays’, small chips containing hundreds to thousands of known DNA fragments in a very small area (centimeter scale), would be more amenable to the quick scans performed on Gattaca employees. These DNA microarrays have been used for a variety of genetic analyses, for example probing the gene expression of a particular cell type at any point in time, with measurement based on attachment of light-based (fluorescent) markers to small microchips suited for high-density detection of a vast number of different DNA sequences (see images below, Creative Commons on Wiki).
A new DNA profiling technology using a microchip-based VLPA (Variable-Length Probe Array) was published by scientists at Stanford University in 2005 (J Forensic Sci, Sept. 2005, Vol. 50, No. 5, see image below).
The paper describes a microarray device displaying DNA fragments of various (known) lengths, to which a target containing an tandem repeat sequences of unknown repeat length can be hybridized (action of one DNA matching up to its ‘complementary’ or “opposite” DNA), revealing the length of the unknown fragment(s). This technique has the potential to give an electronic read-out of DNA fragment lengths in a sample much faster than an electrophoresis-based separation technology. According to Kemp et al, “…this technology could be easily adapted into portable, rapid detection systems for use in forensic identification and military applications in the field. Once integrated with a microfluidics system for sample preparation, hybridization, and enzymatic digestion, as well as an electronic system for detection readout, the entire system could ultimately be contained in a package the size of a laptop computer or handheld device.” Maybe coming close to a Gattaca world of rampant genetic screening for the differentiation of ‘Valids’ from ‘In-Valids’?
The FBI of today routinely uses DNA profiles as a means of genetic evidence identification (i.e. finding out who the DNA left at the scene of a crime ‘belongs’ to). If enough VNTR loci (variable number tandem repeats from specific areas on more than one of our 23 different DNA chromosome pairs) are studied, the chance of two individuals sharing the same DNA profile is less than one in a hundred billion. The US FBI CODIS, or Combined DNA Index System, currently uses 13 different STR sequences (short tandem repeats) for their DNA databases on criminals and missing persons. Despite the theoretically high specificity of a DNA profile, lab errors or lifting of partial or degraded DNA samples from a crime scene may result in questionable accuracy for identification purposes, and thus evidence from the genetic profiling tests must be interpreted and used with care. There are also some debates about the ethics of DNA databases persons found innocent, as set forth in the following articles and blogs: All UK ’must be on DNA database", Reclaim you DNA, and DNA Database News in the UK.
Check back in the next few weeks as I cover the next two topics in the Science of Gattaca:
2. Genetic Sequencing: The possibility of Gattaca
3. Genetic Engineering and Reproductive Technologies: The ‘How’ of Gattaca
Kemp JT, Davis RW, White RL, Wang SX, & Webb CD (2005). A novel method for STR-based DNA profiling using microarrays. Journal of forensic sciences, 50 (5), 1109-13 PMID: 16225215