Spl seminar on 4th Oct

[Office Biotechnology]

Dear all,

There will be Special seminar as per details given below.

All are welcome to attend the same.

Date and Time:  4th of October, 2018 at 2.30pm 

Venue:   BT Seminar Hall

 Topic: Rewriting the Blueprint of Life

by Genome Editing and Synthetic Genomics

Speaker: Professor Srinivasan Chandrasegaran

Department of Environmental Health and Engineering

 Johns Hopkins School of Public Health

 615 North Wolfe Street

Baltimore, Maryland 21205, USA

Abstract:

Our research of FokI restriction enzyme led to the creation of zinc finger nucleases (ZFNs), the first truly targetable reagents which showed pre-determined DNA sequences could be addressed for cleavage by protein engineering. Studies on the mechanism of cleavage by 3-finger ZFNs established that the preferred substrates were paired binding sites, which doubled the size of the target sequence recognition from 9 to 18 bp, long enough to specify a unique genomic locus in plant and mammalian cells. Soon afterwards, we showed that a ZFN-induced targeted DSB stimulates homologous recombination in frog oocytes, ushering in the era of genome editing. Competing transcription activator-like effector nucleases (TALENs), which are based on bacterial TALEs fused to the FokI cleavage domain, expanded this capability. The fact that ZFNs and TALENs have been used for targeted genome editing of more than 40 different organisms and cell types attests to the success of protein engineering. The other technology platform for delivering a targeted DSB to cellular genomes to stimulate site-specific recombination is that of the RNA-guided nucleases, which are based on the naturally occurring Type II prokaryotic CRISPR-Cas9 system. Unlike ZFNs and TALENs that use protein motifs for DNA sequence recognition, CRISPR-Cas9 depends on RNA-DNA recognition. The advantages of the CRISPR-Cas9 system - the ease of RNA design for new targets and the dependence on a single, constant Cas9 protein - have led to its wide adoption by research laboratories around the world. We have used all three technology platforms for the generation and genetic correction of disease-specific human induced pluripotent stem cells (hiPSCs).

In 2014, we reported the design and total synthesis of a functional 272,871-base pair designer eukaryotic chromosome, synIII that is based on the 316,617-base pair native Saccharomyces cerevisiae chromosome III. Changes to synIII included TAG/TAA stop-codon replacements, deletion of subtelomeric regions, introns, transfer RNAs, transposons and silent mating loci as well as insertion of loxPsym sites to enable genome scrambling. SynIII is functional in S. cerevisiae. In 2017, we reported the complete design of a synthetic yeast genome, Sc2.0, a highly modified version of Saccharomyces cerevisiae genome reduced in size by nearly 8%, with 1.1 megabases of the synthetic genome deleted, inserted, or altered. Sc2.0 design was implemented using Biostudio, an open-source framework developed for eukaryotic genome design. Individual synthetic yeast chromosomes are being built by Sc2.0 Consortium teams around the world to achieve complete Sc2.0 genome synthesis. Our lab is currently working on the complete synthesis of the synIX chromosome.

The lecture will give an historical overview of the development of programmable nucleases, discuss our work on genome editing of disease-specific hiPSCs, and then summarize the synthetic yeast (Sc2.0) project. ​

BT Office

Department of Biotechnology

Bhupat and Jyoti Mehta School of Biosciences

IIT Madras, Pin - 600 036

Phone : 044-2257 4100

Email : btof...@iitm.ac.in