Genome engineering

Dr Orr Yarkoni

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I’ve been involved in Synthetic Biology for better part of the last decade. My PhD work at Newcastle University focused on facilitating bio-electronic interface via engineered pathways as part of a larger collaborative grant to create a bio-robotic hybrid device. My more recent work at the University of Cambridge was on developing a field-use whole-cell Arsenic Biosensor for deployment in South Asia (

I’m relatively new at working with plants and the opportunity to reengineer the Marchantia polymorpha plastid as part of the Open Plant initiative is a great point of transition into this sphere. The main focus of my contribution to Open Plant is to reconstruct the entire 121kb plastid genome in a way that makes it easier to manipulate, facilitating future work on plastid transformation in M. polymorpha and, in time, other plants. I am also working together with Haydn King from the Ajioka Lab on creating a codon optimised reporter toolkit for use in the M. polymorpha plastid, consisting of a 13 fluorescent reporters across a wide spectrum ranging from near UV to near infrared. The codon optimisation platform should also become a useful tool for future work on plastid manipulation, in Marchantia and beyond.

I worked with Jim Ajioka and Jonathan Openshaw on a science/arts collaborative project that came to be known as Syn City. The idea was to create dynamic, living sculptures using modified E. coli such that all the “paint” was living. Jonathan designed 3D printed structures of which we made moulds to cast Agar with an integrated 3D printed mesh skeleton. The modified bacteria could then be deposited on the structure, which developed colour over time.

Dr Aytug Tuncel

I am applying the genome editing tools to generate novel, commercially or nutritionally valuable glucans in model crop species. The primary objective of my OpenPlant project is to generate potatoes that contain digestion-resistant starches with two major nutritional benefits: reduced calorie intake from consumption of chips, crisps and other potato-based foods and increased supply of complex carbohydrates to the microbiota of the lower gut that reduces risk of several diseases including colorectal cancer and type II diabetes.

More specifically, the project involves knocking out the gene(s) of starch branching enzymes I and/or II using crispr-CAS9 method thereby increasing the ratio of amylose to amylopectin (linear to branched starch chains) in tubers without significantly compromising the starch yield. The engineered starch will be less accessible to starch degrading enzymes, thus more resistant to digestion.

Dr Oleg Raitskin

My project involves optimization of CRISPR/Cas9 methodology of genome editing in plants. CRISPR/Cas9 is a method of choice to perform genome engineering. There are however significant limitations which prevent broader implementation of this technology in plants.

These limitations include variable efficiency of editing at different targets, off target activity, inefficient inheritance of the created mutations, ability to edit simultaneously several targets, limited selection of targets/PAM repertoire and the need to segregate Cas9 and sgRNA from the created mutations. Numerous configurations of CRISPR/Cas9 designed to address these limitations had been published. Our aim is to establish a uniform testbed and toolkit, where many of these configurations are tested under the same conditions and their editing efficiency and off target activity will be assessed. In order to minimize variability in transgenic expression we established editing essay in plant protoplasts.

Our experimental design includes transforming protoplasts from the same harvest with different configurations of CRISPR/Cas9, including Cas9 variants which specifically edit NGG, NGAG, NGCG and NNGGGT PAMs , Cpf1s which recognise TTTN PAM, and SpCas9 variants with reduced off target activity, and assessing frequency of indels and double stranded breaks activity employing DNA capture assays and Next Generation Sequencing. Currently we gained experience in efficient extraction and transformation of the protoplasts from different plant species using our CRISPR/Cas9 constructs and we are establishing high throughput protoplast transformation methodology using automatic dispenser. In the next step we will attempt to regenerate plants from the edited protoplasts. We also trying to find the ways to perform successful CRISPR/Cas9 assisted targeted repair of gene of interest. We follow the two-step strategy: transforming the plants with “landing pad” with subsequent insertion of the repair template. Successful insertion of the repair template should restore the herbicide resistance and facilitate selection of the plants with successful repair.

I participate in the proposal for Open Plant funding titled “Establishing Low Cost Microfluidic System for Single Cell Analysis” (Dr. Steven Burgess is a principal applicant). The aim of the project is to establish cost-effective microfluidic device for single cell sorting and analysis. Significant reduction of the cost comparatively to the commercially available systems is achieved by producing some of the parts of the device such as microscope and syringe part with 3D printing technology and utilizing open source materials and repositories. Among various applications for this device will be sorting the transformed protoplasts according to the cell size and strength of the fluorescence of the transgene, and cost-effective miniaturizing and automatizing Golden Gate cloning assembly reactions.