This case study was designed to help students explore the molecular mechanisms of the spliceosome and how SARS-CoV-2 impacts host cell spliceosomal function while interpreting figures from primary literature (A. K. Banjeree, et al., Cell 183:1325-1339, e1-e10, 2020, https://doi.org/10.1016/j.cell.2020.10.004). \"Pete and the Missing Scissors\" was designed and implemented in the spring of 2022 and fall of 2022 in two large-enrollment (150+) introductory molecular biology courses at a large, public research institution. The case study was formatted in alignment with the National Center for Case Study Teaching in Science (NCCSTS) framework, which has been shown to be an effective, student-centered approach to teaching complex biological concepts at the undergraduate level. The case study had four student learning objectives (SLOs) that aligned with Bloom\'s Revised Taxonomy and required students to develop an understanding of the molecular mechanisms of splicing and analyze and interpret a figure from primary literature. Both formative and summative assessment questions are included in this activity, with each question mapping to one of the case study SLOs. Summative assessment questions were given in a pre-/post-manner, and a paired t-test was used to evaluate differences between students\' pre- and post-assessment scores. Assessment results demonstrated that students in both courses mastered each of the SLOs of this case study, given the significant increase in post-assessment scores compared to the pre-assessment. These findings indicate that the \"Pete and the Missing Scissors\" case study is an effective approach to develop students\' understanding of the spliceosome, as well as ability to interpret figures from primary literature.

UNASSIGNED: Clinical outcomes for mucosal melanomas are often poor due to a lack of effective systemic drug therapies. Identifying driver genes in mucosal melanoma may enhance the understanding of disease pathogenesis and provide novel opportunities to develop effective therapies.
UNASSIGNED: Somatic variant analysis identified SF3B1 (6 of 27: 22%) as the most commonly mutated gene, followed by KIT (3 of 27: 11%). Other less frequently mutated genes (4% otherwise stated) included BRAF (7%), NRAS (7%), ARID2, CTNNB1, DICER1, MAP2K1, NF1, PTEN, SETD2 and TP53. Recurrent SF3B1 p.R625 hotspot mutations were exclusively detected in vulvovaginal (5 of 19: 26%) and anorectal melanomas (3 of 5:60%). The only other SF3B1 mutation was a p.C1123Y mutation that occurred in a conjunctival mucosal melanoma.SF3B1-mutated patients were associated with shorter overall survival (OS; 34.9 months) and progression-free survival (PFS; 16.9 months) compared to non-SF3B1-mutated patients (OS: 79.7 months, log-rank P = 0.1172; PFS: 35.7 months, log-rank P = 0.0963).
UNASSIGNED: Molecular subgroups of mucosal melanoma with SF3B1 mutations occurred predominantly in the vulvovaginal region. SF3B1 mutations may have a negative prognostic impact.
UNASSIGNED: Formalin-fixed biopsies were collected from 27 pathologically-confirmed mucosal melanomas. Genomic DNA was isolated from the tumor tissue and sequenced using a novel dual-strand amplicon sequencing technique to determine the frequency and types of mutations across 45 target genes.

BACKGROUND: Type-2 diabetes mellitus (T2DM) is a major health problem with increasing incidence, which severely impacts cardiovascular disease. Because T2DM is associated with altered gene expression and aberrant splicing, we hypothesized that dysregulations in splicing machinery could precede, contribute to, and predict T2DM development.
METHODS: A cohort of patients with cardiovascular disease (CORDIOPREV study) and without T2DM at baseline (at the inclusion of the study) was used (n = 215). We determined the expression of selected splicing machinery components in fasting and 4 h-postprandial peripheral blood mononuclear cells (PBMCs, obtained at baseline) from all the patients who developed T2DM during 5-years of follow-up (n = 107 incident-T2DM cases) and 108 randomly selected non-T2DM patients (controls). Serum from incident-T2DM and control patients was used to analyze in vitro the modulation of splicing machinery expression in control PBMCs from an independent cohort of healthy subjects.
RESULTS: Expression of key splicing machinery components (e.g. RNU2, RNU4 or RNU12) from fasting and 4 h-postprandial PBMCs of incident-T2DM patients was markedly altered compared to non-T2DM controls. Moreover, in vitro treatment of healthy individuals PBMCs with serum from incident-T2DM patients (compared to non-T2DM controls) reduced the expression of splicing machinery elements found down-regulated in incident-T2DM patients PBMCs. Finally, fasting/postprandial levels of several splicing machinery components in the PBMCs of CORDIOPREV patients were associated to higher risk of T2DM (Odds Ratio > 4) and could accurately predict (AUC > 0.85) T2DM development.
CONCLUSIONS: Our results reveal the existence of splicing machinery alterations that precede and predict T2DM development in patients with cardiovascular disease. FUND: ISCIII, MINECO, CIBERObn.