The Professional Identity of STEM Faculty as Instructors of Course-based Research Experiences.

The professional identity of scientists has historically been cultivated to value research over teaching, which can undermine initiatives that aim to reform science education. Course-Based Research Experiences (CRE) and the inclusive Research and Education Communities (iREC) are two successful and impactful reform efforts that integrate research and teaching. The aim of this study is to explicate the professional identity of instructors who implement a CRE within an established iREC and to explore how this identity contributes to the success of these programs.

Models of Classroom Assessment for Course-Based Research Experiences.

Course-based research pedagogy involves positioning students as contributors to authentic research projects as part of an engaging educational experience that promotes their learning and persistence in science. To develop a model for assessing and grading students engaged in this type of learning experience, the assessment aims and practices of a community of experienced course-based research instructors were collected and analyzed. This approach defines four aims of course-based research assessment - 1) Assessing Laboratory Work and Scientific Thinking; 2) Evaluating Mastery of Concepts, Quantitative Thinking and Skills; 3) Appraising Forms of Scientific Communication; and 4) Metacognition of Learning - along with a set of practices for each aim.

Genome analysis of reveals implications for soft rot pathogenicity in plants.

Soft rot disease causes devastating losses to crop plants all over the world, with up to 90% loss in tropical climates. To better understand this economically important disease, we isolated four soft rot-causing strains from rotted vegetables. Notably, has only recently been identified as a soft rot pathogen and a comprehensive genomic analysis and comparison has yet to be conducted.

Genome Sequences of Soft Rot-Causing Pseudomonas Isolates from Spinach.

Two Pseudomonas strains (SR17 and SR18) were isolated from soft rot-diseased spinach leaves. Here, we report their genome sequences and characteristics.

Genome Sequences of Soft Rot-Causing Isolates from Different Vegetables.

Eleven strains were isolated from soft rot-diseased vegetables. Here, we report their genome sequences and characteristics. Five isolates were found to be Pectobacterium versatile, while the other six were determined to be Pectobacterium brasiliense.

ZapA and ZapB form an FtsZ-independent structure at midcell.

Cell division in Escherichia coli begins with the polymerization of FtsZ into a ring-like structure, the Z-ring, at midcell. All other division proteins are thought to require the Z-ring for recruitment to the future division site. Here, it is reported that the Z-ring associated proteins ZapA and ZapB form FtsZ-independent structures at midcell.

Structure-function analysis of the LytM domain of EnvC, an activator of cell wall remodelling at the Escherichia coli division site.

Proteins with LytM (Peptidase_M23) domains are broadly distributed in bacteria and have been implicated in a variety of important processes, including cell division and cell-shape determination. Most LytM-like proteins that have been structurally and/or biochemically characterized are metallo-endopeptidases that cleave cross-links in the peptidoglycan (PG) cell wall matrix. Notable exceptions are the Escherichia coli cell division proteins EnvC and NlpD.

Dynamic microtubules and endomembrane cycling contribute to polarity establishment and early development of Ectocarpus mitospores.

Many zygotes and spores of brown algae are photosensitive and establish a developmental axis in accordance with directional light cues. Ectocarpus siliculosus is being advanced as a genetic and genomic model organism for investigating brown alga development, and this report investigates photopolarization of the growth axis of mitospores. When exposed to unidirectional light, mitospores photopolarized and established a growth axis such that germination was preferentially localized to the shaded hemisphere of the spore body.

Non-cell autonomous regulation of life cycle transitions in the model brown alga Ectocarpus.

The model brown alga Ectocarpus has a haploid-diploid life cycle, involving alternation between two independent multicellular generations, the gametophyte and the sporophyte. Recent work has shown that alternation of generations is not determined by ploidy but is rather under genetic control, involving at least one master regulatory locus, OUROBOROS (ORO). Using cell biology approaches combined with measurements of generation-specific transcript abundance we provide evidence that alternation of generations can also be regulated by non-cell autonomous mechanisms.

Immunostaining of Ectocarpus cells.

This article describes an immunostaining protocol for Ectocarpus that was optimized for the detection of tubulin but could be used with any suitable antibody. Ectocarpus has small but relatively transparent cells and the uniseriate filaments can be grown directly attached to the surface of microscope slides. These features make Ectocarpus particularly suitable for high resolution imaging approaches, both in vivo or after fixation.

Extraction of high-quality genomic DNA from Ectocarpus.

For some applications, such as genome sequencing and high-throughput genotyping with multiple markers, it is necessary to use high-quality genomic DNA. This article describes how to obtain several micrograms of high-quality, cesium chloride-purified DNA from 1 g of Ectocarpus filaments. We also recommend using DNA of this quality for quantitative RT-PCR control reactions.

Isolation and regeneration of protoplasts from Ectocarpus.

This article describes how to obtain isolated cells with no surrounding cell wall by enzymatic digestion of Ectocarpus filaments. The resultant protoplasts are totipotent and regenerate to produce individual algae under appropriate culture conditions. The yield of protoplasts and their capacity to regenerate are highly dependent on the Ectocarpus strain used, the stage of the life cycle, and the culture conditions.

Genetic crosses between Ectocarpus strains.

This article describes a procedure for conducting crosses between different strains of Ectocarpus. Crossing gametophytes to obtain the sporophyte generation is the most technically challenging stage of this process because diploid sporophytes have to be distinguished from the haploid partheno-sporophytes that result from the parthenogenetic germination of unfused gametes. This requires careful monitoring of the progeny of the genetic cross until they have developed sufficiently to be transferred to a separate Petri dish.

How to cultivate Ectocarpus.

This article describes the standard procedure for growing Ectocarpus in the laboratory. The culture is started with partheno-sporophyte (or sporophyte) filaments because this is the stage that is usually maintained in strain collections. The standard medium is Provasoli-enriched natural seawater (PES), but Ectocarpus can also be grown in artificial seawater, which allows more precise control over the culture conditions.

Ectocarpus: a model organism for the brown algae.

The brown algae are an interesting group of organisms from several points of view. They are the dominant organisms in many coastal ecosystems, where they often form large, underwater forests. They also have an unusual evolutionary history, being members of the stramenopiles, which are very distantly related to well-studied animal and green plant models.

An ATP-binding cassette transporter-like complex governs cell-wall hydrolysis at the bacterial cytokinetic ring.

ATP-binding cassette transporters are ubiquitous membrane protein complexes that move substrates across membranes. They do so using ATP-induced conformational changes in their nucleotide-binding domains to alter the conformation of the transport cavity formed by their transmembrane domains. In Escherichia coli, an ATP-binding cassette transporter-like complex composed of FtsE (nucleotide-binding domain) and FtsX (transmembrane domain) has long been known to be important for cytokinesis, but its role in the process has remained mysterious.

A fail-safe mechanism in the septal ring assembly pathway generated by the sequential recruitment of cell separation amidases and their activators.

During cytokinesis in Escherichia coli, the peptidoglycan (PG) layer produced by the divisome must be split to promote cell separation. Septal PG splitting is mediated by the amidases: AmiA, AmiB, and AmiC. To efficiently hydrolyze PG, the amidases must be activated by LytM domain factors.

Asymmetric microtubule arrays organize the endoplasmic reticulum during polarity establishment in the brown alga Silvetia compressa.

Polarity is a fundamental characteristic of most cell types, and is crucial to early development of the brown alga Silvetia compressa. In eukaryotes the cytoskeleton plays an important role in generating cellular asymmetries. While it is known that F-actin is required for polarization and growth in most tip-growing cells, the roles of microtubules are less clear.

Localization and function of Kinesin-5-like proteins during assembly and maintenance of mitotic spindles in Silvetia compressa.

Background: Kinesin-5 (Eg-5) motor proteins are essential for maintenance of spindle bipolarity in animals. The roles of Kinesin-5 proteins in other systems, such as Arabidopsis, Dictyostelium, and sea urchin are more varied. We are studying Kinesin-5-like proteins during early development in the brown alga Silvetia compressa.

Phospholipid signaling during stramenopile development.

Development of sessile organisms requires adaptation to an ever-changing environment. In order to respond quickly to these challenges, complex signaling mechanisms have evolved to facilitate cellular modifications. The importance of phospholipid-based signaling pathways in plants, as well as animals, has recently been gaining attention.

The microtubule plus-end binding protein EB1 functions in root responses to touch and gravity signals in Arabidopsis.

Microtubules function in concert with associated proteins that modify microtubule behavior and/or transmit signals that effect changes in growth. To better understand how microtubules and their associated proteins influence growth, we analyzed one family of microtubule-associated proteins, the END BINDING1 (EB1) proteins, in Arabidopsis thaliana (EB1a, EB1b, and EB1c). We find that antibodies directed against EB1 proteins colocalize with microtubules in roots, an observation that confirms previous reports using EB1-GFP fusions.

Phospholipase D signaling regulates microtubule organization in the fucoid alga Silvetia compressa.

Recent studies in higher plants or animals have shown that phospholipase D (PLD) signaling regulates many aspects of development, including organization of microtubules (MTs), actin and the endomembrane system. PLD hydrolyzes structural phospholipids to form the second messenger phosphatidic acid (PA). To begin to understand the signaling pathways and molecules that regulate cytoskeletal and endomembrane arrays during early development in the brown alga, Silvetia compressa, we altered PLD activity by applying butyl alcohols to zygotes.

Comparative genomic analysis of three Leishmania species that cause diverse human disease.

Leishmania parasites cause a broad spectrum of clinical disease. Here we report the sequencing of the genomes of two species of Leishmania: Leishmania infantum and Leishmania braziliensis. The comparison of these sequences with the published genome of Leishmania major reveals marked conservation of synteny and identifies only approximately 200 genes with a differential distribution between the three species.