Bio-Synthesis Newsletter - May 2018

BNAs dramatically improve the specificity of CRISPR-Cas9!

Cromwell et al. in 2018 reported that the incorporation of bridged nucleic acids, BNAs, at specific positions within CRISPR-RNAs (crRNAs) significantly improves Cas9 DNA cleavage specificity in vitro and cells. The researchers reasoned that modified crRNAs enhance specificity by impairing the formation of the stable “zipped” conformation during hybridization to off-target sequences. These results indicate that BNA modified crRNA improve the specificity of the CRISPR-Cas9 system and also illustrate the power of recently developed synthetic nucleic acid technologies to solve problems in enzyme specificity.

I-motif DNA structures in the cell nuclei

DNA can fold into different structures such as G-quadruplexes and i-motifs. These DNA structures interrupt normal DNA base pairing. I-motifs are formed by a set of cytosines that pair with protonated cytosines, connecting U-shaped DNA strands. Zeraati et al. (2018) now report that i-motif structures are formed in regulatory regions of the human genome, including in promoter and telomeric regions. 

To detect i-motif structures in human cells, the research group used fluorescent-dye-labeled antibody fragments that bind i-motifs with high selectivity and affinity. The study showed that i-motifs were present in gene promoter regions and telomeres. These findings suggest that i-motifs are regulatory elements in the genome.

Baking soda removes pesticides from apples

To reduce pesticide exposure when eating fruits pesticide residues should be removed from produce. Yang et al. in 2017 showed that surface pesticide residues can be effectively removed using a solution of sodium bicarbonate or baking soda (NaHCO₃). Tap water or Clorox bleach were found to work not as well. The research group showed that washing pesticide contaminated apples with a 10 mg/mL NaHCO₃ solution for approximately 15 min completely removed thiabendazole or phosmet surface residues. Using this method for washing pesticide contaminated apples allows the removal of pesticide residues without losing bioactive compounds found in the skin of plant.

Vitamin B6 helps remember dreams

Vitamine B6 or pyridoxine is commonly found in food and also used as a dietary supplement. Recently researchers have observed that supplementation with vitamin B6 before bed can enhance the vividness and recall of dreams. Vitamin B6 refers to a group of water-soluble compounds essential for human health which can be analyzed using HPLC. Foods such as whole grains cereals, legumes, fruits, for example, bananas and avocados, vegetables, milk, cheese, eggs, red meat, liver, and fish, all contain vitamin B6. Aspy et al. in 2018 investigated the effect of vitamin B6 supplementation before going to bed and found that vitamin B6 significantly increased the amount of dream content recalled in a dose-dependent manner.   

Please note that creation and use of synthetic oligos for CRISPR applications requires a license from ERS genomics, the holders of IP for CRISPR technology. We do not have a license to provide synthetic oligos used in CRISPR technology from ERSGenomics. Contact ERSGenomics.com for further information.