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.

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.

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.

Engaging and gauging (engauging) first-generation, under-represented minority undergraduate general biology students through processes of inquiry, critical thinking, and affective learning is vital as they develop their scientific identity. An important challenge is how we can establish communities of practice and instill in our first-generation students self-awareness and reflection as they apply, analyze, and evaluate data on biological principles. In my article, I describe an innovative weekly assignment for my first generation Hispanic and Native Indigenous students called Quizfolio: quiz and mini-portfolios on biological principles and themes outlined in Vision and Change. Within a SOAR framework that will be introduced in my article, quizfolios provide an active learning space for students to integrate inclusive student-centered, in-class discussions and longitudinal lab inquiries in a first-year undergraduate biology course through metacognition and reflection-in-action. This transformative, culturally responsive mentoring approach encourages first-generation undergraduates to bring self-awareness to unclear or confusing topics that are clarified at the start of class or lab settings, and provides future framework for long-term retention of biological concepts.

To facilitate its goal of fostering department transformation, the Partnership for Undergraduate Life Sciences Education (PULSE) organizes some of its work into five geographic regions and leverages the expertise of the PULSE Fellows in each region. This article examines how these Regional Networks have driven department-level changes through outreach activities, use of the PULSE Rubrics as a diagnostic tool to help departments to advance the Vision and Change recommendations, and implementation of the PULSE framework to address local needs and challenges. We present impact data through Regional Network activities and identify commonalities in successes and challenges across all the geographic regions. Through reports from the Northeast, Southeast, Southwest, Northwest, and Midwest Great Plains, we highlight each Regional Network’s accomplishments in influencing the adoption of PULSE strategies to implement the Vision and Change recommendations to transform departments.