Virtually the Same? Evaluating the Effectiveness of Remote Undergraduate Research Experiences.

In-person undergraduate research experiences (UREs) promote students' integration into careers in life science research. In 2020, the COVID-19 pandemic prompted institutions hosting summer URE programs to offer them remotely, raising questions about whether undergraduates who participate in remote research can experience scientific integration and whether they might perceive doing research less favorably (i.e., not beneficial or too costly). To address these questions, we examined indicators of scientific integration and perceptions of the benefits and costs of doing research among students who participated in remote life science URE programs in Summer 2020. We found that students experienced gains in scientific self-efficacy pre- to post-URE, similar to results reported for in-person UREs. We also found that students experienced gains in scientific identity, graduate and career intentions, and perceptions of the benefits of doing research only if they started their remote UREs at lower levels on these variables. Collectively, students did not change in their perceptions of the costs of doing research despite the challenges of working remotely. Yet students who started with low cost perceptions increased in these perceptions. These findings indicate that remote UREs can support students' self-efficacy development, but may otherwise be limited in their potential to promote scientific integration.

"How Do We Do This at a Distance?!" A Descriptive Study of Remote Undergraduate Research Programs during COVID-19.

The COVID-19 pandemic shut down undergraduate research programs across the United States. A group of 23 colleges, universities, and research institutes hosted remote undergraduate research programs in the life sciences during Summer 2020. Given the unprecedented offering of remote programs, we carried out a study to describe and evaluate them. Using structured templates, we documented how programs were designed and implemented, including who participated. Through focus groups and surveys, we identified programmatic strengths and shortcomings as well as recommendations for improvements from students' perspectives. Strengths included the quality of mentorship, opportunities for learning and professional development, and a feeling of connection with a larger community. Weaknesses included limited cohort building, challenges with insufficient structure, and issues with technology. Although all programs had one or more activities related to diversity, equity, inclusion, and justice, these topics were largely absent from student reports even though programs coincided with a peak in national consciousness about racial inequities and structural racism. Our results provide evidence for designing remote Research Experiences for Undergraduates (REUs) that are experienced favorably by students. Our results also indicate that remote REUs are sufficiently positive to further investigate their affordances and constraints, including the potential to scale up offerings, with minimal concern about disenfranchising students.

The Artificial Sweetener, Erythritol, Has Insecticidal Properties Against Pear Psylla (Hemiptera: Psyllidae).

Erythritol is a dietary sweetener that is used for low-calorie or diabetic diets. Although safe for human consumption, erythritol is lethal to certain Dipteran pests, but insecticidal effects of erythritol on phloem-feeding insects have yet to be examined. Our goal was to determine whether erythritol has insecticidal activity against pear psylla, Cacopsylla pyricola (Foerster) (Hemiptera: Psyllidae). We first demonstrated that ingestion of erythritol solutions compared with water by pear psylla caused reduced feeding, impaired motor functions, and reduced survival time of adults. We then tested whether foliar treatment of pear leaves with erythritol was also lethal to pear psylla. Foliar treatment of erythritol led to reduced 3-d survival of pear psylla nymphs and adults, and reduced rates of oviposition by pear psylla adults. Psylla adults also preferred to settle on untreated leaves than on erythritol-treated leaves in preference assays. Finally, we conducted field experiments to test whether applications of erythritol provided pear trees with protection against pear psylla under natural field conditions. Those experiments showed a reduction in pear psylla nymphs on erythritol-treated trees compared with untreated trees, but only if the erythritol was completely dissolved into solution by heating. Laboratory trials confirmed the importance of heating. Results of our experiments demonstrate that erythritol is insecticidal to pear psylla nymphs and adults and provide the first report that erythritol is lethal to a phloem-feeding insect. These findings suggest that erythritol may provide a new safe and effective tool for the management of pear psylla.

Glial cell ecology in zebrafish development and regeneration.

Zebrafish have been found to be the premier model organism in biological and biomedical research, specifically offering many advantages in developmental biology and genetics. The zebrafish (Danio rerio) has the ability to regenerate its spinal cord after injury. However, the complete molecular and cellular mechanisms behind glial bridge formation in zebrafish remains unclear. In our review paper, we examine the extracellular and intracellular molecular signaling factors that control zebrafish glial cell bridging and glial cell development in the forebrain. The interplay between initiating and terminating molecular feedback cycles deserve future investigations during glial cell growth, movement, and differentiation.

Beyond the lab bench: Pathways in inclusion, equity, and diversity in biology education and social justice.

Over the past six years, I describe my personal journey into promoting inclusion, equity, and diversity in biology education and social justice. In my personal journey, I will describe how I found my passion in mentoring and teaching Native American, Latinx, and non-traditional undergraduates in cell and developmental biology. I will also describe how Dr. Karen Gross' concept of lasticity aligned with culturally-responsive teaching and mentoring can help foster transformative learning for all undergraduates.

Pbx4 is Required for the Temporal Onset of Zebrafish Myocardial Differentiation.

Proper control of the temporal onset of cellular differentiation is critical for regulating cell lineage decisions and morphogenesis during development. Pbx homeodomain transcription factors have emerged as important regulators of cellular differentiation. We previously showed, by using antisense morpholino knockdown, that Pbx factors are needed for the timely activation of myocardial differentiation in zebrafish. In order to gain further insight into the roles of Pbx factors in heart development, we show here that zebrafish pbx4 mutant embryos exhibit delayed onset of myocardial differentiation, such as delayed activation of tnnt2a expression in early cardiomyocytes in the anterior lateral plate mesoderm. We also observe delayed myocardial morphogenesis and dysmorphic patterning of the ventricle and atrium, consistent with our previous Pbx knock-down studies. In addition, we find that pbx4 mutant larvae have aberrant outflow tracts and defective expression of the proepicardial marker tbx18. Finally, we present evidence for Pbx expression in cardiomyocyte precursors as well as heterogeneous Pbx expression among the pan-cytokeratin-expressing proepicardial cells near the developing ventricle. In summary, our data show that Pbx4 is required for the proper temporal activation of myocardial differentiation and establish a basis for studying additional roles of Pbx factors in heart development.

Of Heart & Kidneys: Hands-On Activities for Demonstrating Organ Function & Repair.

A major challenge in teaching organ development and disease is deconstructing a complex choreography of molecular and cellular changes over time into a linear stepwise process for students. As an entry toward learning developmental concepts, I propose two inexpensive hands-on activities to help facilitate learning of (1) how to identify defects in heart and kidneys and (2) what evolutionarily conserved strategies from organ development can be applied to understand how to repair these defects. The ease of assembling these activities, combined with traffic flow as a metaphor for physiological function of heart and kidneys, provides students the opportunity to explore and discover biological concepts in organ formation and disease.

The luminal connection: from animal development to lumopathies.

Interconnection of epithelial tubules is a crucial process during organogenesis. Organisms have evolved sets of molecular and cellular strategies to generate an interconnected tubular network during animal development. Spatiotemporal control of common cellular strategies includes dissolution of the basement membrane, apoptosis, rearrangements of cell adhesion junctions, and mesenchymal-like invasive cellular behaviors prior to tubular interconnection. Different model systems exhibit varying degrees of active invasive-like behaviors that precede tubular interconnection, which may reflect changes in cell polarity or differential adhesive cell states. Studies in this newly-emerging field of tubular interconnections will provide a greater understanding of pediatric diseases and cancer metastasis, as well as generate fundamentally new insights into lumen formation pathology, or lumopathies.

Invasion of distal nephron precursors associates with tubular interconnection during nephrogenesis.

Formation of a functional renal network requires the interconnection of two epithelial tubes: the nephron, which arises from kidney mesenchyme, and the collecting system, which originates from the branching ureteric epithelium. How this connection occurs, however, is incompletely understood. Here, we used high-resolution image analysis in conjunction with genetic labeling of epithelia to visualize and characterize this process. Although the focal absence of basal lamina from renal vesicle stages ensures that both epithelial networks are closely apposed, we found that a patent luminal interconnection is not established until S-shaped body stages. Precursor cells of the distal nephron in the interconnection zone exhibit a characteristic morphology consisting of ill-defined epithelial junctional complexes but without expression of mesenchymal markers such as vimentin and Snai2. Live-cell imaging revealed that before luminal interconnection, distal cells break into the lumen of the collecting duct epithelium, suggesting that an invasive behavior is a key step in the interconnection process. Furthermore, loss of distal cell identity, which we induced by activating the Notch pathway, prevented luminal interconnection. Taken together, these data support a model in which establishing the distal identity of nephron precursor cells closest to the nascent collecting duct epithelium leads to an active cell invasion, which in turn contributes to a patent tubular interconnection between the nephron and collecting duct epithelia.