Mitotic cells undergo extensive changes in shape and size through the altered regulation and function of their membrane trafficking machinery. Disabled 2 (Dab2), a multidomain cargo-specific endocytic adaptor and a mediator of signal transduction, is a potential integrator of trafficking and signaling. Dab2 binds effectors of signaling and trafficking that localize to different intracellular compartments. Thus, differential localization is a putative regulatory mechanism of Dab2 function. Furthermore, Dab2 is phosphorylated in mitosis and is thus regulated in the cell cycle. However, a detailed description of the intracellular localization of Dab2 in the different phases of mitosis and an understanding of the functional consequences of its phosphorylation are lacking. Here, we show that Dab2 is progressively displaced from the membrane in mitosis. This phenomenon is paralleled by a loss of co-localization with clathrin. Both phenomena culminate in metaphase/ anaphase and undergo partial recovery in cytokinesis. Treatment with 2-methoxyestradiol, which arrests cells at the spindle assembly checkpoint, induces the same effects observed in metaphase cells. Moreover, 2-methoxyestradiol also induced Dab2 phosphorylation and reduced Dab2/clathrin interactions, endocytic vesicle motility, clathrin exchange dynamics, and the internalization of a receptor endowed with an NPXY endocytic signal. Serine/threonine to alanine mutations, of residues localized to the central region of Dab2, attenuated its phosphorylation, reduced its membrane displacement, and maintained its endocytic abilities in mitosis. We propose that the negative regulation of Dab2 is part of an accommodation of the cell to the altered physicochemical conditions prevalent in mitosis, aimed at allowing endocytic activity throughout the cell cycle.

Energy is a central concept in science in every discipline and also an essential player in many of the issues facing people everywhere on the globe. However, studies have shown that by the end of K‐12 schooling, most students do not reach the level of understanding required to be able to use energy to make sense of a wide range of phenomena. Many researchers have questioned whether the conceptual foundations of traditional approaches to energy instruction may be responsible for students' difficulties. In response to these concerns, we developed and tested a novel approach to middle school physical science energy instruction that was informed by the recommendations of the Framework for K‐12 Science Education (National Research Council, 2012a) and the Next Generation Science Standards (NGSS) (NGSS Lead States, 2013). This new approach differs substantially from more traditional approaches to energy instruction in that it does not require energy forms and it emphasizes connections between energy, systems, and fields that mediate interaction‐at‐a‐distance. We investigated student learning during this novel approach and contrasted it with student learning within a comparable unit based on a more traditional approach to energy instruction. Our findings indicate that students who learned in the new approach outperformed students who learned in the traditional approach in every quantitative and qualitative aspect considered in this study, irrespective of their prior knowledge of energy. They developed more parsimonious knowledge networks in relation to energy that focused primarily around the concept of energy transfer. This study warrants further investigation into the value of this new approach to energy instruction in both middle and high school.

Worldwide, teachers are expected to engage their students in authentic practices, like scientific modeling.Research suggests that teachers experience challenges when integrating modeling in their classroom instruction, with one explanation that teachers themselves lack the necessary modeling competence. Currently, theoretical conceptualizations structure the modeling competence into three dimensions: meta-modeling knowledge, modeling practice, and modeling products. While each of these dimensions is well researched on its own and the three dimensions are commonly expected to be highly positively related, studies investigating their specific relationships are widely lacking.Aiming to fill this gap, the present study investigated the meta-modeling knowledge, modeling practice, and modeling products of 35 secondary preservice biology teachers engaging in a black box modeling task.Data were collected with an established pen-and-paper questionnaire consisting of five constructed response items assessing meta-modeling knowledge and by videotaping the participants engaging in the black box modeling task. Herein, the three dimensions of

No abstract