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…
Cover artwork by Daisy S. Lim It was the first multicellular eukaryotic genome sequenced to apparent completion, but it turns out the Caenorhabditis elegans reference that’s been used as a resource for the past 20 years does not exactly correspond with any N2 strain that exists today. Assembled using sequence data from N2 and CB1392 populations of uncertain lineage grown in at least two different laboratories during the 1980s and 1990s, accuracy of the C. elegans reference genome is limited both by genetic variants and by the limitations of the technology of the time (clone-based Sanger technology). It is believed…
It was the coolest critter Erin Bernberg (@ErinBernberg) had ever worked with – quite literally. The senior scientist at the University of Delaware Sequencing and Genotyping Center, a PacBio certified service provider, received a shipment of tiny, live ice worms from Washington State University and immediately faced several challenges. How would she get them out of their ice cubes? How would she isolate DNA from the delicate, dark pigmented creatures? And would she be able to extract enough DNA to sequence? Thanks to the new PacBio low DNA input protocol, the answer to the last question was yes. In fact,…
Anopheles coluzzii mosquito UPDATED January 18, 2019 This paper is now available at Genes. ORIGINAL POST December 19, 2018 High-quality reference and de novo genomes have been celebrated by geneticists, population biologists and conservationists alike, but it’s been a dream deferred for entomologists and others grappling with limited DNA samples, due to previous relatively high DNA input requirements (~5 μg for standard library protocol). A new low-input protocol now makes it possible to create high-quality de novo genome assemblies from just 100 ng of starting genomic DNA, without the need for time-consuming inbreeding or pooling strategies. The targeted release date for…
Haemophilus influenzae, a sample of which was deposited to the NCTC collection by Alexander Fleming, from his own nose. The genomes of 3,000 strains of bacteria, including some of the deadliest in the world, are now available to researchers as part of an ambitious project by the UK’s National Collection of Type Cultures (NCTC), in partnership with the Wellcome Sanger Institute and PacBio. Plague, cholera, streptomyces, and 250 strains of E. coli, are among the reference genomes created, as well as all ‘type strains’ of the bacteria in the collection — the first strains that describe the species and are…
Genetic knowledge is powerful when it comes to breeding. The ability to trace desirable traits to the gene level can help create plants and animals that are adapted to existing and emerging challenges, such as temperature tolerance, productivity, or disease resistance. By crossing two breeds of cattle, Angus (Bos taurus taurus) and Brahman (Bos taurus indicus), from opposite ends of the species spectrum, breeders can benefit from the Angus’s high productivity in cool environments and the Brahman’s tolerance for harsh, hot climates and the diseases and parasites found there. Genetically and phenotypically, the two subspecies are very different. And,…