Analysis of 16S ribosomal RNA has been used for phylogenetics and identifying prokaryotes for decades. But just as scientists have had to refine the Linnaean taxonomy system based on genomic discoveries, improvements in sequencing technology are changing 16S analysis best practices. Several dominant microbial genera in Sakinaw Lake could only be resolved via Full Length 16S or were missed by V4 sequencing (gray boxes). Singer, E. et al. (2016) Researchers at the Joint Genome Institute, for instance, conducted a detailed benchmarking study and found that traditional methods of 16S analysis — which look at just a piece of the gene…
The SMRTbell gDNA Sample Amplification Kit enables whole genome amplification starting from as little as 5 ng of genomic DNA. It’s one of the questions we hear most often from scientists working with small organisms: Is it possible to generate truly high-quality, long-read data from minuscule amounts of DNA? With our new kit for ultra-low DNA input projects, the answer is: Absolutely! The new workflow dramatically reduces the requirements for DNA quantity. Now, scientists need only 5 ng of genomic DNA to kick off a SMRT Sequencing project — that’s less than 2% of the starting volume needed for our…
With PacBio HiFi sequencing data now readily available for organisms of any size, many exciting results have been published featuring new de novo assembly methods optimized for highly accurate long reads. These methods have produced assemblies for a variety of organisms at quality levels never before thought possible — as measured by completeness, contiguity and correctness. We feel privileged to collaborate with the scientific community on the development of these tools. From Small to Tall When the USDA wanted to rapidly assemble the Asian Giant Hornet as part of its real-time invasive species response initiative, they turned to a tool…
A pangenome identifies which portions of the genome are unique and which overlap and are therefore core to the species. It has recently become apparent how important it is to sequence more than one individual to characterize the genomic variation within a species. This makes sense if you consider that sexually reproducing organisms are a mix of their parents and, therefore, not identical. This is just as true in crops as it is in humans. So, it’s not surprising that when a group of researchers from several institutions in China embarked on de novo genome assemblies of several accessions of…
How do bacteria manipulate plant biology to cause blight and rot? Why are some pathogen strains more virulent than others? How can we engineer resistant staple food crops? These are pressing questions facing researchers looking to sustain and increase crop production against the backdrop of a changing environment. For one major clade of pathogens, Xanthomonas spp, the answers lay locked within TAL effector genes (TALEs), but assembling these highly variable, repetitive regions was a long-standing obstacle. The key to finally unraveling the tangled assemblies was PacBio long-read sequencing. Code-breaker Adam J. Bogdanove from Cornell University. Photo by Jesse Winter Plant…
In an exciting new preprint, scientists from the HudsonAlpha Institute for Biotechnology and the University of Alabama at Birmingham describe the use of PacBio highly accurate long-read sequencing to identify pathogenic variants responsible for previously undiagnosable, rare neurodevelopmental disorders. Lead author Susan Hiatt (@suzieqhiatt), senior author Gregory Cooper, and collaborators conducted genomic analyses of several family trios in an attempt to find causal genetic variants that had been missed with earlier studies. “Large fractions of [neurodevelopmental disorders] cannot be attributed to currently detectable genetic variation,” they report. “This is likely, at least in part, a result of the fact that…
In the recent precisionFDA Truth Challenge V2, which evaluated methods for variant calling in human genomes, approaches that use PacBio HiFi reads delivered the highest precision and recall in all categories: genome-wide, specifically in difficult-to-map regions, and in the major histocompatibility complex (Figure 1). The challenge had 64 total entries: 17 using PacBio HiFi reads, 24 using Illumina reads, 3 using Oxford Nanopore reads, and 20 using multiple technologies. Twenty-five of the 26 overall most accurate callsets used PacBio HiFi reads (12 PacBio-only, 13 multi-technology), including all of the top 12 (3 PacBio-only, 9 multi-technology). A submission from Google DeepVariant…
With a nickname like “murder hornet,” it’s no wonder the two-inch long Asian giant hornet (Vespa mandarinia) has caused a stir amongst those terrified of insect invasions. Various species of paper wasp (left) compared to the Asian giant hornet (right) Photo by Hanna Royals, USDA. The wasps — which are actually more dangerous to bees than humans — have made another recent appearance in Washington state, and Agricultural Research Service (ARS) scientists are hoping a new rapidly-generated genome sequence of one of the insects will help in their quest to quash an invasion. Released August 6, the first high-quality genome…
Whether you are seeking to characterize microbial diversity in the gut, or distinguish between pathogenic and commensal bacteria on the skin, full-length 16S rRNA sequencing using PacBio systems is a valuable tool for metagenomics studies, according to microbiology researchers in a recent webinar. The HiFi advantage. With HiFi sequencing, every read yields 7-9 complete genes. PacBio microbiology expert Meredith Ashby (@AshbyMere) began the webinar by highlighting some of the strengths of the Sequel II System in metagenomics research. One of the biggest advantages is the ability to do gene prediction directly on high-quality HiFi reads, without the need for any…
“We are now embarking on an era where all genetic variation in an individual will be completely discovered,” write Glennis Logsdon (@glennis_logsdon), Mitchell Vollger (@mrvollger), and Evan Eichler in a recent Nature Reviews Genetics paper. “Hundreds and ultimately thousands of new human reference genomes will be produced.” A decade ago that would have sounded impossible, but today this bold proclamation is widely accepted in the genomics community — a telling sign of the remarkable innovation that has driven genome sequencing in recent years. In their review, the University of Washington scientists give credit for much of these accomplishments to advancements in…
It’s not unusual for progeny to outperform their parents, and it’s often the goal in plant breeding. But tracing the molecular basis of such heterosis can be difficult, especially in diploid species with high genetic diversity and allele-specific expression like maize. Cold Spring Harbor scientists have tackled the challenge using the PacBio Iso-Seq method and a new tool, IsoPhase. As reported in Nature Communications Biology, Bo Wang, Doreen Ware, and colleagues performed an isoform-level phasing study in maize using the temperate line B73 and the tropical line Ki11, as well as their reciprocal crosses (B73 × Ki11; Ki11 × B73),…
Tackling larger and larger genomes has been an attractive pursuit for many scientists as sequencing technologies improve at rapid rates. But what about the other end of the spectrum — the tiny organisms that comprise much of the diversity of life? An obvious obstacle to decoding the DNA of small organisms such as insects, nematodes and other arthropods is collecting enough of it to actually sequence (usually multiple micrograms worth). Until recently, the solution was to pool DNA from many of these tiny creatures to create a representative sample, and extrapolate the biology of the individual constituents from there. But…
It’s well known that finding the genetic cause of rare diseases can be complex — that’s why so many remain unsolved. But researchers are beginning to get a grasp on just how complex these conditions can be, thanks to the heightened power of PacBio. PacBio principal scientist Aaron Wenger kicked off a recent webinar with a quote from University of Washington scientist Evan Eichler, who said “there are three key aspects to genetic disease associations: comprehensive variant discovery, accurate allele-frequency determination, and an understanding of the pattern of normal variation and its effect on expression.” Wenger explained how HiFi reads…
As the flurry of research around the SARS-CoV-2 virus continues at an unprecedented pace, scientists are beginning to tackle some of the more complex immunological responses with the help of Single Molecule, Real-Time (SMRT) sequencing. Hundreds of people tuned in live to a special May 7 webinar, “Understanding SARS-CoV-2 and host immune response to COVID-19 with PacBio sequencing.” Meredith Ashby, Director of Microbial Genomics at PacBio, described some of the resources being generated by both PacBio and our users in order to help labs who are using SMRT Sequencing technology to investigate SARS-CoV-2 and COVID-19. These include two microbial sequencing…
The strides scientists have made in rare disease research lately is truly impressive. For an overview of recent progress, we encourage you to check out a new article in The Pathologist from our own Luke Hickey (@Luke_Hickey), Senior Director of Strategic Marketing. It offers a great overview of how scientists have used long-read sequencing to find the genetic explanations for elusive rare diseases. “Never before have our laboratory techniques been so successful at identifying rare diseases and elucidating their underlying biological causes,” Hickey writes. “The knowledge we obtain today opens the door to new treatments, giving hope to people who…