It is interesting to posit that work to sequence important crop genomes and their subsequent geznetic engineering to obtain desirable traits that increase the world food supply may ultimately have a greater impact on human health than has the sequencing of the human genome.
This possibility seems more likely when one considers that, while most crop genomes sequenced to date have used conventional methods, the use of NGS to sequence and identify loci contributing to desirable or “domesticated” traits such as drought or salinity tolerance, resistance to pathogens, or reduced time to maturity, will markedly accelerate these efforts.
In particular, with a high-quality reference sequence in hand, short-read technologies can be utilized to sequence and then align reads from a strain exhibiting desirable traits onto the reference genome.13
Proper analysis reveals genes and regulatory regions that differ from the reference, and a secondary or “interpretational” analysis promotes those variants with the most likely phenotype-altering impact for downstream functional studies. Each suspect variant then can be biologically evaluated to determine its contribution to the trait using the wide variety of transformation techniques available.
Once identified, engineering of the crop species for the desired new trait can begin.14 Quality reference genomes are now available for rice15, maize16, and grape17, and are well under way for tomato, potato, wheat, and cassava, among others.
One significant impact of NGS has been to accelerate efforts in cancer genomics, i.e., identifying the differences in DNA sequence variation, RNA expression, or methylation (or all three) in matched tumor and normal tissues from the same patient.
The large capacity of NGS instrumentation and the emphasis on cancer genomics as a fundamental discovery mechanism has enabled large cooperative projects—such as The Cancer Genome Atlas (TCGA), the International Cancer Genome Consortium (ICGC), and the Pediatric Cancer Genome Project (PCGP)—to aim at characterizing these differences in hundreds of cancer cases.
Furthermore, the comprehensive scope and digital sensitivity of NGS methods has allowed genome-wide comparisons of tumor-normal pairs18-21, a re-examination of hypotheses about tumor evolution22-23, and whole-genome sequencing for therapeutic options in patients.24-25
The incorporation of NGS into the clinical trial setting to characterize patient samples prior to determining the trial arm to which each patient is best assigned and into the prognostic/diagnostic setting for cancer care will combine to demonstrate that NGS-based methods can improve clinical efficacy, an important step toward transforming the standard of cancer care in the near term.
Meanwhile, the discipline of pathology26 is being radically altered, with training in genomic tests and their interpretation, to provide the medical expertise required to support the use of DNA-based tests in the clinical setting.
In addition to cancer genomics, NGS has now successfully been applied to solve causes of pediatric genetic disease27-28, also demonstrating clinical efficacy in diagnosis as well as valuable insights into de novo genetic disease.
This brief survey of the impact of next-generation sequencing and its transformative power is not meant to be comprehensive but rather exemplary. The remarkable reach of NGS into disparate scientific endeavors, both commercial and research-oriented, is revitalizing associated aspects of science, computation, and the economy.
The challenges and innovation required to analyze and properly interpret large sequence datasets has effectively breathed new life into the disciplines of computational biology and bioinformatics. Similarly, the resulting NGS-driven computational infrastructure demands have increased both the need to build data centers and the subscription to large server farms in the grid/cloud environment. These demands not only increase hardware sales and drive innovation but also create jobs across the spectrum from advertising to engineering, administration to construction.
Sequencing instrumentation and associated reagent sales represent an almost uniquely American enterprise at present, and the competition for market share is at a feverish pitch. This has escalated of late, as a new wave of so-called third-generation instruments is being introduced to the market. In this class of instrumentation, run times are measured in a few hours rather than days and although the data volume per instrument is much lower than NGS instruments, so is the cost of reagents and consumables per run.
Using a combination of speed and economy, these new instruments will likely ease the introduction of massively parallel DNA sequencing into the clinical setting, facilitate food and pharmaceutical product safety testing, revolutionize agricultural genomics, and expand even further the effective reach of DNA sequencing technology into our daily lives.
However, threats to this very desirable trajectory exist. They clearly include the likely dramatic decreases in government funding for scientific research, and as importantly, the downward spiral in our emphasis as a country on the importance of education.
Only our complacency as a nation in these areas will allow this current area of scientific innovation to slip away.