A Hot-Swappable Genetic Switch: Building an inducible and trackable functional assay for the essential gene MEDIATOR 21.

Essential genes, estimated at approximately 20% of the genome, are broadly expressed and required for reproductive success. They are difficult to study, as interfering with their function leads to premature death. Transcription is one of the essential functions of life, and the multi-protein Mediator complex coordinates the regulation of gene expression at nearly every eukaryotic promoter.

A history-dependent integrase recorder of plant gene expression with single-cell resolution.

During development, most cells experience a progressive restriction of fate that ultimately results in a fully differentiated mature state. Understanding more about the gene expression patterns that underlie developmental programs can inform engineering efforts for new or optimized forms. Here, we present a four-state integrase-based recorder of gene expression history and demonstrate its use in tracking gene expression events in Arabidopsis thaliana in two developmental contexts: lateral root initiation and stomatal differentiation.

A comparative analysis of stably expressed genes across diverse angiosperms exposes flexibility in underlying promoter architecture.

Promoters regulate both the amplitude and pattern of gene expression-key factors needed for optimization of many synthetic biology applications. Previous work in Arabidopsis found that promoters that contain a TATA-box element tend to be expressed only under specific conditions or in particular tissues, while promoters that lack any known promoter elements, thus designated as Coreless, tend to be expressed more uniformly. To test whether this trend represents a conserved promoter design rule, we identified stably expressed genes across multiple angiosperm species using publicly available RNA-seq data.

Engineering activatable promoters for scalable and multi-input CRISPRa/i circuits.

Dynamic, multi-input gene regulatory networks (GRNs) are ubiquitous in nature. Multilayer CRISPR-based genetic circuits hold great promise for building GRNs akin to those found in naturally occurring biological systems. We develop an approach for creating high-performing activatable promoters that can be assembled into deep, wide, and multi-input CRISPR-activation and -interference (CRISPRa/i) GRNs.

A comparative analysis of stably expressed genes across diverse angiosperms exposes flexibility in underlying promoter architecture.

Promoters regulate both the amplitude and pattern of gene expression-key factors needed for optimization of many synthetic biology applications. Previous work in found that promoters that contain a TATA-box element tend to be expressed only under specific conditions or in particular tissues, while promoters which lack any known promoter elements, thus designated as Coreless, tend to be expressed more ubiquitously. To test whether this trend represents a conserved promoter design rule, we identified stably expressed genes across multiple angiosperm species using publicly available RNA-seq data.

An integrase toolbox to record gene-expression during plant development.

There are many open questions about the mechanisms that coordinate the dynamic, multicellular behaviors required for organogenesis. Synthetic circuits that can record in vivo signaling networks have been critical in elucidating animal development. Here, we report on the transfer of this technology to plants using orthogonal serine integrases to mediate site-specific and irreversible DNA recombination visualized by switching between fluorescent reporters.

Synthesis and Self-Assembly of Cellulose Microfibrils from Reconstituted Cellulose Synthase.

Cellulose, the major component of plant cell walls, can be converted to bioethanol and is thus highly studied. In plants, cellulose is produced by cellulose synthase, a processive family-2 glycosyltransferase. In plant cell walls, individual β-1,4-glucan chains polymerized by CesA are assembled into microfibrils that are frequently bundled into macrofibrils.