The most well-characterized organelle contact sites are those between the endoplasmic reticulum (ER) and mitochondria. Increased understanding is being gained of how ER–mitochondria contact sites are organized and which factors converge at this interface, some of which may provide a tethering function. The role of the ER–mitochondria junction in coordinating the functions of these two organelles is also becoming clearer, and it has been shown to be involved in the regulation of lipid synthesis, Ca2+ signalling and the control of mitochondrial biogenesis and intracellular trafficking.

Summary Endocytic cargo and Rab GTPases are segregated to distinct domains of an endosome. These domains maintain their identity until they undergo fission to traffic cargo. It is not fully understood how segregation of cargo or Rab proteins is maintained along the continuous endosomal membrane, or what machinery is required for fission. Endosomes form contact sites with the ER that are maintained during trafficking. Here, we show that stable contacts form between the ER and endosome at constricted sorting domains and that free diffusion of cargo is limited at these positions. We demonstrate that the site of constriction and fission for early and late endosomes is spatially and temporally linked to contact sites with the ER. Lastly, we show that altering ER structure and dynamics reduces the efficiency of endosome fission. Together these data reveal a surprising role for ER contact in defining the timing and position of endosome fission.

Endosomes do not traffic autonomously but instead associate with the ER membrane. ER tubules wrap around and maintain contact with both early and late endosomes by ER ring rearrangements. As endosomes mature, they increase the degree of their ER association, which suggests that the ER might play a role in endosomal maturation.

Course-based undergraduate research experiences (CUREs) provide students opportunities to engage in research in a course. Aspects of CURE design, such as providing students opportunities to make discoveries, collaborate, engage in relevant work, and iterate to solve problems are thought to contribute to outcome achievement in CUREs. Yet how each of these elements contributes to specific outcomes is largely unexplored. This lack of understanding is problematic, because we may unintentionally underemphasize important aspects of CURE design that allow for achievement of highly valued outcomes when designing or teaching our courses. In this work, we take a qualitative approach and leverage unique circumstances in two offerings of a CURE to investigate how these design elements influence outcome achievement. One offering experienced many research challenges that increased engagement in iteration. This level of research challenge ultimately prevented achievement of predefined research goals. In the other offering, students experienced fewer research challenges and ultimately achieved predefined research goals. Our results suggest that, when students encounter research challenges and engage in iteration, they have the potential to increase their ability to navigate scientific obstacles. In addition, our results suggest roles for collaboration and autonomy, or directing one’s own work, in outcome achievement.

Understanding how students develop biology interests and the roles interest plays in biology contexts could help instructors and researchers to increase science, technology, engineering, and mathematics students’ motivation and persistence. However, it is currently unclear how interest has been defined or measured in the biology education research literature. We analyzed this body of literature to determine how interest has been defined and used by the biology education research community. Specifically, we determined the extent to which previously published work drew on theories that conceptualize interest. Further, we identified studies that measured student interest in biology and characterized the types of measures used. Our findings indicate that biology education researchers typically describe interest as a relationship involving positive feelings between an individual and a physical object, activity, or topic of focus. We also found that interest is often not defined, theories involving interest are not often consulted, and the most common measures of interest only assess a single aspect of the construct. On the basis of these results, we make suggestions for future research seeking to examine biology students’ interest. We hope that this analysis can serve as tool for biology educators to improve their own investigations of students’ interest and measure outcomes of interest-generating educational activities.