Ericka Shin. The Daily Californian, 18 February 2016. http://www.dailycal.org/2016/02/18/caribou-biosciences-co-founded-campus-researcher-jennifer-doudna-receives-intellectual-property-rights-crispr-technology/
Caribou Biosciences, founded by UC Berkley professor Jennifer Doudna, was awarded a patent for the use of CRISPR/Cas9 technology in diagnostic applications. This technique can be used to detect genomic rearrangements and is much narrower in scope than the CRISPR patents currently under dispute between UC Berkley and the Broad Institute.
Luke Alphey, Nature Biotechnology (2016) 34:149-150 http://www.ncbi.nlm.nih.gov/pubmed/26849518
Gene drives use selfish genes that spread through a population regardless of its ability to confer individual fitness. Multiple researchers have proposed using gene drives to control the spread of vector-borne diseases, such as malaria. Carried by certain species of mosquitos, malaria is one of the most dangerous human pathogens, gene drives could control or eliminate malaria by modifying mosquitoes to be resistant to malaria or by elimination of mosquito fertility. This opinion article highlights how CRISPR/Cas9 gene drives would work in theory as well as a discussion on the technological and ethical problems facing gene drives.
Price, A.A et al. Trends in Microbiology (2016) http://www.ncbi.nlm.nih.gov/pubmed/26852268
Viral diseases result in acute and chronic illnesses, often with limited treatment options. CRISPR/Cas9 technology could be used as to treat chronic viral diseases such as HIV/AIDS, Hepatitis B, and HPV. However, the research into these applications is still in its infancy. This review highlights the potential for CRISPR/Cas9 technology to be adapted for use as a eukaryotic antiviral therapy as well as the areas where more research is needed.
Jennifer Doudna, AAAS 2016 Annual Meeting Plenary Session. 13 February 2016. http://livestream.com/AAASmtg/events/4772683/videos/112285338
Jennifer Doudna delivered one of the plenary sessions at the 2016 AAAS Annual Meeting on the science, medical applications, and ethical implications of CRISPR/Cas9 technology. During her talk she discussed how CRISPR/Cas9 was discovered while explaining the mechanism behind Cas9 binding and DNA cleavage.
Science Friday, Public Radio International 12 February 2016 http://www.sciencefriday.com/segments/could-genetically-engineered-insects-squash-mosquito-borne-disease/
Science Friday host Ira Flatow discusses CRISPR/Cas9 and gene drives and the ethical considerations for their use. Kevin Esvelt, an evolutionary engineer at MIT, and Anthony James, a researcher at the University of California contributed to the discussion.
Melody Petersen, 12 February 2016. Los Angeles Times http://www.latimes.com/business/la-fi-human-gene-editing-20160212-story.html
The California Stem Cell Institute is considering funding experiments on human embryos using CRISPR/Cas9 technology. Federal law prohibits the use of federal taxes to fund research involving human embryos; however states can use their tax money to fund this kind of research. The California Stem Cell Institute is currently reviewing its ethics guidelines to determine if they will fund research involving human embryos and CRISPR technology. So far no studies have been funded.
Antonio Regalado, 9 February, 2016. MIT Technology Review. https://www.technologyreview.com/s/600774/top-us-intelligence-official-calls-gene-editing-a-wmd-threat/
James Clapper, US Director of National Intelligence, compared CRISPR/Cas9 gene editing to WMD’s in February of 2016. His worries stem from the ease at which rogue states could use CRISPR/Cas9 techniques to engineer biological weapons. To date researchers have not used CRISPR/Cas9 technology to engineer biological weapons, though it does hold the potential for such negative applications.
Schwartz, C.M. et al. ACS Synthetic Biology (2016) http://www.ncbi.nlm.nih.gov/pubmed/26714206
Yarrowia lipolytica is a versatile oleaginous yeast used to model lipid pathways and produce polymers commercially. However, its use has been limited due to its reliance on selectable markers during genome engineering. Researchers from the University of California-Riverside have used CRISPR/Cas9 technology to develop a new modular plasmid named pCRISPRyl that can induce homologous recombination with ~60% efficiency without the use of selectable markers.
Richardson, C.D. et al. Nature Biotech (2016) http://www.ncbi.nlm.nih.gov/pubmed/26789497
After DNA cleavage with CRISPR/Cas9, cleaved DNA is repaired by one of two mechanisms. Non-homologous end joining (NHEJ) is an error-prone repair mechanism that usually results in a non-functional gene product and is commonly used by researchers to knockout targeted genes. Homology-directed repair (HDR) is the insertion of DNA sequences that have ends homologous to the cleavage sight and can be used for precise sequence replacement/addition to the genome, however the efficiency of HDR is extremely low. Through the use of in vitro kinetic studies, Richardson et al. determined that Cas9 has a very slow rate of dissociation (~6 hours) with targeted DNA, however the non-target strand is released much faster with Cas9 remaining bound to only the targeted strand. By rationally designing single-stranded DNA donor templates complementary to the non-target strand Richardson et al. increased the efficiency of HDR in human cell lines up to 60% when using eight wild-type or nickase variants of Cas9, and up to 0.7% when using a catalytically dead Cas9 that binds, but cannot cleave DNA.
Sarah Zhang, Wired.com, January 14, 2016. http://www.wired.com/2016/01/crispr-modification/
Despite the importance of Cas9, no one has observed exactly how Cas9 cleaves targeted DNA. Previous crystal structures place the nuclease cleavage domains too far away for DNA cleavage to occur. In a recent Science publication (http://science.sciencemag.org/content/early/2016/01/13/science.aad8282) Jennifer Doudna’s group solved the crystal structure of Cas9 primed to cut targeted DNA. This crystal structure may allow the engineering of more accurate Cas9 endonucleases.