Journal: ACS synthetic biology
Article Title: A Hot-Swappable Genetic Switch: Building an Inducible and Trackable Functional Assay for the Essential Gene MEDIATOR 21.
doi: 10.1021/acssynbio.5c00085
Figure Lengend Snippet: Figure 4. Engineering and rapid prototyping of the “hot-swap” isoform switch approach. (A) Schematic of the predicted behavior for the MED21 Swap. Lateral root primordia will switch the expression of the rescue construct from wild-type (blue) to mutant isoform (red). (B) Design of the integrase target. The target is composed of two integrase sites (triangles) surrounding a constitutive promoter (pUBQ10), and each MED21 isoform is fused to the P2A self-cleaving peptide sequence and a fluorescent reporter (mTurquoise or mScarlet). In the basal state, MED21 and mTurquoise are produced. Once the PhiC31 integrase is expressed, it mediates inversion of the DNA between the integrase sites, inverting the promoter and leading to production of mMED21 and mScarlet. (C) Alignment of the AtMED21 N-terminal mutants. (D−G) Epifluorescence microscopy analysis of wild-type and mMED21 swap lateral root initiation in Arabidopsis primary transformants. Microscopy images were taken on a 20x objective, and the scale bar represents 50 μm. (H) Lateral root density (LRD per mm) and (I) lengths of lateral roots (Lateral root length in mm) from primary transformant lines were quantified at 14 days post germination from the indicated Integrase Swap type. At least 15 independent primary transformant lines were tested for each swap type. Lines were transplanted to soil and PCR genotyped for the med21 genotype. In (H), the LRD data points from med21 homozygous plants are colored in blue, while heterozygotes are colored dark gray, and ungenotyped samples are colored light gray. Letters indicate significant difference (ANOVA and Tukey HSD multiple comparison test; p < 0.001). In (I), data are presented as violin plots with nested boxplots to demonstrate that medians and interquartile ranges are comparable across conditions.
Article Snippet: The Arabidopsis MED21:HA sequence was amplified by PCR with appropriate Golden Gate restriction sites and the construction of integrase targets was performed by Golden Gate reaction in the modified pGreenIIHygr vector containing compatible Golden Gate sites defined in Guiziou et al.20 Plasmids used for construction of the novel targets are available at Addgene: 5 prime side mScarlet cassette - L0-T4 tRBSC_mScarlet (Addgene #195887), Integrase site flanked pUBQ10 - L0-T1 Target PhiC31−(Addgene https://doi.org/10.1021/acssynbio.5c00085 ACS Synth.
Techniques: Expressing, Construct, Mutagenesis, Sequencing, Produced, Epifluorescence Microscopy, Microscopy, Comparison