Acute exposure of Nicotine during puncture injury activates an epidermal wound response reaction.

Epidermal wound reaction after injury can be visualized in embryos by transgenic fluorescent wound reporters. A "local" reaction is limited to the epidermal cells surrounding a wound site occurs in embryos. A "global" reaction extends beyond the wound site to all epidermal cells occurs in immune response mutants (e.

Translating Research as an Approach to Enhance Science Engagement.

The impact of research depends on the effective communication of discoveries. Scientific writing is the primary tool for the dissemination of research, and is an important skill that biomedical trainees have to develop. Despite its importance, scientific writing is not part of the mainstream curriculum.

Toll pathway is required for wound-induced expression of barrier repair genes in the epidermis.

The epidermis serves as a protective barrier in animals. After epidermal injury, barrier repair requires activation of many wound response genes in epidermal cells surrounding wound sites. Two such genes in encode the enzymes dopa decarboxylase () and tyrosine hydroxylase ().

Embryos as a Model for Wound-Induced Transcriptional Dynamics: Genetic Strategies to Achieve a Localized Wound Response.

While many studies have established a paradigm for tissue repair at the level of cellular remodeling, it is not clear how an organism restricts a response only to the injured region of a damaged tissue. Skin, the largest organ in the human body, is prone to injury, and repair of epidermal tissue represents a medically relevant system to investigate. Studies in provide a robust genetic system to identify molecular components that will positively impact repair and healing.

Microinjection wound assay and in vivo localization of epidermal wound response reporters in Drosophila embryos.

The Drosophila embryo develops a robust epidermal layer that serves both to protect the internal cells from a harsh external environment as well as to maintain cellular homeostasis. Puncture injury with glass needles provides a direct method to trigger a rapid epidermal wound response that activates wound transcriptional reporters, which can be visualized by a localized reporter signal in living embryos or larvae. Puncture or laser injury also provides signals that promote the recruitment of hemocytes to the wound site.

Serine proteolytic pathway activation reveals an expanded ensemble of wound response genes in Drosophila.

After injury to the animal epidermis, a variety of genes are transcriptionally activated in nearby cells to regenerate the missing cells and facilitate barrier repair. The range and types of diffusible wound signals that are produced by damaged epidermis and function to activate repair genes during epidermal regeneration remains a subject of very active study in many animals. In Drosophila embryos, we have discovered that serine protease function is locally activated around wound sites, and is also required for localized activation of epidermal repair genes.

The functions of grainy head-like proteins in animals and fungi and the evolution of apical extracellular barriers.

The Grainy head (GRH) family of transcription factors are crucial for the development and repair of epidermal barriers in all animals in which they have been studied. This is a high-level functional conservation, as the known structural and enzymatic genes regulated by GRH proteins differ between species depending on the type of epidermal barrier being formed. Interestingly, members of the CP2 superfamily of transcription factors, which encompasses the GRH and LSF families in animals, are also found in fungi--organisms that lack epidermal tissues.

Duox, Flotillin-2, and Src42A are required to activate or delimit the spread of the transcriptional response to epidermal wounds in Drosophila.

The epidermis is the largest organ of the body for most animals, and the first line of defense against invading pathogens. A breach in the epidermal cell layer triggers a variety of localized responses that in favorable circumstances result in the repair of the wound. Many cellular and genetic responses must be limited to epidermal cells that are close to wounds, but how this is regulated is still poorly understood.

Multiple transcription factor codes activate epidermal wound-response genes in Drosophila.

Wounds in Drosophila and mouse embryos induce similar genetic pathways to repair epidermal barriers. However, the transcription factors that transduce wound signals to repair epidermal barriers are largely unknown. We characterize the transcriptional regulatory enhancers of 4 genes-Ddc, ple, msn, and kkv-that are rapidly activated in epidermal cells surrounding wounds in late Drosophila embryos and early larvae.

Two small regulatory RNAs establish opposing fates of a developmental axis.

Small RNAs are important regulators of gene expression. In maize, adaxial/abaxial (dorsoventral) leaf polarity is established by an abaxial gradient of microRNA166 (miR166), which spatially restricts the expression domain of class III homeodomain leucine zipper (HD-ZIPIII) transcription factors that specify adaxial/upper fate. Here, we show that leafbladeless1 encodes a key component in the trans-acting small interfering RNA (ta-siRNA) biogenesis pathway that acts on the adaxial side of developing leaves and demarcates the domains of hd-zipIII and miR166 accumulation.

Specification of adaxial cell fate during maize leaf development.

Dorsoventral (adaxial/abaxial) polarity of the maize leaf is established in the meristem and is maintained throughout organ development to coordinate proper outgrowth and patterning of the leaf. rolled leaf1 (rld1) and leafbladeless1 (lbl1) are required for the specification of the adaxial/upper leaf surface. rld1 encodes a class III homeodomain-leucine zipper (HD-ZIPIII) protein whose adaxial expression is spatially defined by miRNA166-directed transcript cleavage on the abaxial side.

microRNA-mediated repression of rolled leaf1 specifies maize leaf polarity.

In both animals and plants, many developmentally important regulatory genes have complementary microRNAs (miRNAs), which suggests that these miRNAs constitute a class of developmental signalling molecules. Leaves of higher plants exhibit a varying degree of asymmetry along the adaxial/abaxial (upper/lower) axis. This asymmetry is specified through the polarized expression of class III homeodomain/leucine zipper (HD-ZIPIII) genes.