New type of kill switch to prevent genetically modified microbes from wreaking

first_img This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Science Fiction writers dreamed up the idea of mad scientists creating microorganisms that somehow get out into the world and kill everyone long before modern scientists had the skill to actually do it—but now that technology does exist and along with it fear that in trying to do something good, such as creating a cure for a bacterial disease, researchers could create a monster virus that not only harms patients, but jumps to others and causes serious harm or death. That fear is not ungrounded, as most biological researchers will attest, and that is why some of them are working on making genetically modified organisms safe. The idea is to modify genes to cause the organism to note when some chemical is present, and if so, to self-destruct—a modified virus or bacteria, for example, would die if exposed to a chemical present in the atmosphere. While such an approach is deemed practical by many, others would like to have access to a means for using the same technique on different organisms—those who hold patents on GMOs, for example, would like to be able to kill off their product if it gets into the hands of another entity. To meet that need, the researchers with this new effort came up with two new types of kill switches, which they have named ‘Deadman’ and ‘Passcode.’The Deadman solution is a new take on the kill switch idea from old time trains, a certain chemical must always be present or the modified microbe will die. Passcode, on the other hand is more complex, it combines the idea of a needed chemical and the absence of another. Microbes could be modified to be able to live only in the presence of two different molecules, for example, and the absence of another, or the reverse could be true. The designer could choose whichever “passcode” they desire.The main hurdle facing these new ideas and any others that may come along, of course, is in being able to prove that the microbes they modify will not evolve in ways that overcome the kill switches, either alone or by interacting with native microbes, making such efforts moot and possibly putting everyone at risk. Citation: New type of kill switch to prevent genetically modified microbes from wreaking havoc (2015, December 8) retrieved 18 August 2019 from https://phys.org/news/2015-12-genetically-microbes-wreaking-havoc.html More information: Clement T Y Chan et al. ‘Deadman’ and ‘Passcode’ microbial kill switches for bacterial containment, Nature Chemical Biology (2015). DOI: 10.1038/nchembio.1979AbstractBiocontainment systems that couple environmental sensing with circuit-based control of cell viability could be used to prevent escape of genetically modified microbes into the environment. Here we present two engineered safeguard systems known as the ‘Deadman’ and ‘Passcode’ kill switches. The Deadman kill switch uses unbalanced reciprocal transcriptional repression to couple a specific input signal with cell survival. The Passcode kill switch uses a similar two-layered transcription design and incorporates hybrid LacI-GalR family transcription factors to provide diverse and complex environmental inputs to control circuit function. These synthetic gene circuits efficiently kill Escherichia coli and can be readily reprogrammed to change their environmental inputs, regulatory architecture and killing mechanism. Researchers use CRISPR to create ‘kill switch’ for GMOs Journal information: Nature Chemical Biology Explore further (Phys.org)—A combined team of researchers from MIT and Harvard has come up with two new ways to hardwire a kill switch into a genetically modified microorganism to prevent it from going rogue. In their paper published in the journal Nature Chemical Biology, the team describes their technique, why they think it is better than other approaches and the ways it could be used. © 2015 Phys.orglast_img read more

National museum to showcase rich silk heritage

first_imgTo Showcase the beautiful silk heritage, an exhibition titled ‘Mudmee: A Shared Silk Heritage’, will be organised by the Royal Thai embassy, New Delhi, in collaboration with the National Museum and Thai Khadi Research Institute, Thammasat University.The art show will feature around 50 pieces of old and new Mudmee silk from Thailand, and a few dresses and accessories made from Thai Mudmeesilk, along with a selection of Indian Ikat silk from the collection of the National Museum. It will be inaugurated by H E Chutintorn Gongsakdi, Ambassador of Thailand, and Dr B R Mani, Director General, National Museum, New Delhi on August 10 and will be on view till September 25. Also Read – Add new books to your shelfThere will be a special lecture and gallery walk by Dr Anucha Thirakanont, Director of Thai Khadi Research Institute and curator of the exhibition at the opening evening. Entry is free on the opening evening whereas a museum ticket is required on other days.Thailand and India have shared a long history of textiles. Various types of textiles were imported from India to Siam for the local market and royal court use since Ayutthaya period (14th – 18th Century). including block-printed or painted cotton (chintz) from Masulipatnam, silk brocade from Banaras, and patola (double ikat silk) from Gujarat. Siamese had commissioned Indian-made textiles with Siamese royal patterns exclusively for the royal court, usually with the flame motifs, as seen in traditional Thai paintings and architecture. At the same time, textiles with simplified or mixed patterns of Indian taste were produced for the general Siamese public. These Indian-Thai patterns and motifs can still be seen in the Mudmee silk in Thailand today.last_img read more