An Exploratory Mixed-Methods Analysis of Factors Contributing to Students' Perceptions of Inclusion in Introductory STEM Courses.

In this exploratory mixed-methods analysis of students' perceptions of inclusion in introductory STEM courses for STEM majors, we asked students to rate inclusion in their class and to provide an open-text explanation of their rating. Analyzing 1930 qualitative responses resulted in a codebook containing academic, identity, and nonspecific categories. The majority of responses (>80%) cited academic factors such as interactions between students and instructors or course elements and policies. Most academic responses aligned with evidence-based teaching practices fostering inclusion, describing a range of strategies and policies instructors can implement to increase students' perceptions of inclusion. A small number of student responses indicated that their perception of the required knowledge background for the course impacted course inclusivity. Few differences in frequency distributions were found between subgroups examined (gender, race and ethnicity, self-reported inclusion score, and discipline). Additionally, tracking a subset of students (135) across three courses revealed that most (80%) cited different factors influencing their perception of inclusion in each course. This suggests students' perceptions of inclusive practices are complex, and most students recognize multiple factors that influence their inclusion. Overall, our findings suggest instructors can significantly influence students' perceptions of inclusion by using multiple inclusive teaching strategies and course policies.

Cleavage-Polyadenylation Factor Cft1 and SPX Domain Proteins Are Agents of Inositol Pyrophosphate Toxicosis in Fission Yeast.

Inositol pyrophosphate (IPP) dynamics govern expression of the fission yeast phosphate homeostasis regulon via their effects on lncRNA-mediated transcription interference. The growth defects (ranging from sickness to lethality) elicited by fission yeast mutations that inactivate IPP pyrophosphatase enzymes are exerted via the agonistic effects of too much 1,5-IP8 on RNA 3'-processing and transcription termination. To illuminate determinants of IPP toxicosis, we conducted a genetic screen for spontaneous mutations that suppressed the sickness of Asp1 pyrophosphatase mutants. We identified a missense mutation, C823R, in the essential Cft1 subunit of the cleavage and polyadenylation factor complex that suppresses even lethal Asp1 IPP pyrophosphatase mutations, thereby fortifying the case for 3'-processing/termination as the target of IPP toxicity. The suppressor screen also identified Gde1 and Spx1 (SPAC6B12.07c), both of which have an IPP-binding SPX domain and both of which are required for lethality elicited by Asp1 mutations. A survey of other SPX proteins in the proteome identified the Vtc4 and Vtc2 subunits of the vacuolar polyphosphate polymerase as additional agents of IPP toxicosis. Gde1, Spx1, and Vtc4 contain enzymatic modules (glycerophosphodiesterase, RING finger ubiquitin ligase, and polyphosphate polymerase, respectively) fused to their IPP-sensing SPX domains. Structure-guided mutagenesis of the IPP-binding sites and the catalytic domains of Gde1 and Spx1 indicated that both modules are necessary to elicit IPP toxicity. Whereas Vtc4 polymerase catalytic activity is required for IPP toxicity, its IPP-binding site is not. Epistasis analysis, transcriptome profiling, and assays of Pho1 expression implicate Spx1 as a transducer of IP8 signaling to the 3'-processing/transcription termination machinery. IMPORTANCE Impeding the catabolism of the inositol pyrophosphate (IPP) signaling molecule IP8 is cytotoxic to fission yeast. Here, by performing a genetic suppressor screen, we identified several cellular proteins required for IPP toxicosis. Alleviation of IPP lethality by a missense mutation in the essential Cft1 subunit of the cleavage and polyadenylation factor consolidates previous evidence that toxicity results from IP8 action as an agonist of RNA 3'-processing and transcription termination. Novel findings are that IP8 toxicity depends on IPP-sensing SPX domain proteins with associated enzymatic functions: Gde1 (glycerophosphodiesterase), Spx1 (ubiquitin ligase), and Vtc2/4 (polyphosphate polymerase). The effects of Spx1 deletion on phosphate homeostasis imply a role for Spx1 in communicating an IP8-driven signal to the transcription and RNA processing apparatus.