Timed inhibition of CDC7 increases CRISPR-Cas9 mediated templated repair.

Repair of double strand DNA breaks (DSBs) can result in gene disruption or gene modification via homology directed repair (HDR) from donor DNA. Altering cellular responses to DSBs may rebalance editing outcomes towards HDR and away from other repair outcomes. Here, we utilize a pooled CRISPR screen to define host cell involvement in HDR between a Cas9 DSB and a plasmid double stranded donor DNA (dsDonor). We find that the Fanconi Anemia (FA) pathway is required for dsDonor HDR and that other genes act to repress HDR. Small molecule inhibition of one of these repressors, CDC7, by XL413 and other inhibitors increases the efficiency of HDR by up to 3.5 fold in many contexts, including primary T cells. XL413 stimulates HDR during a reversible slowing of S-phase that is unexplored for Cas9-induced HDR. We anticipate that XL413 and other such rationally developed inhibitors will be useful tools for gene modification

Bacterial Diversity in Cold Environments of Indian Himalayas

Not AvailableThe remote cold environments of Indian Himalayas are witnessed by extreme situations with a lot of variations in temperatures, low availability of water and nutrients and exposure to a lot of radiations. These extreme environments generally considered unfavourable to growth and survival of plants and animals are usually colonized by the microorganisms capable of growth and survivability under the prevailing severe conditions. Because of the extremophilic enzymes, proteins and biomolecules possessed by cold-adapted microorganism, they are of importance for industry, agriculture and biotechnology. In this chapter, (1) diversity of bacteria present in cold environments based on culturing and metagenomics approaches, (2) microorganisms from cold environments in agriculture, (3) novel bacteria from cold environments and (4) genome sequencing of bacteria from cold environments have been discussed. Bacteria affiliated to various phyla like Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, Acidobacteria, Gemmatimonadetes, Planctomycetes, Chlamydiae, Chlorobi, Chloroflexi, Dictyoglomi, Fibrobacteres, Nitrospirae and Verrucomicrobia have been reported from the Indian Himalayas. Microorganisms belonging to various genera for improving agriculture production under cold environment have been isolated and identified. Twenty-one novel species of bacteria have been isolated from different locations in the cold environments of the Himalayas. A genome of 18 strains isolated from these cold environments has been sequenced and published.Not Availabl