Using yeast to determine the functional consequences of mutations in the human p53 tumor suppressor gene: An introductory course-based undergraduate research experience in molecular and cell biology

Long non-coding RNA and ribosomal protein genes in a yeast ageing model: an investigation for undergraduate research-based learning

The unicellular yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe are widely used eukaryotic model organisms. Research exploiting the tractability of these model systems has contributed significantly to our understanding of a wide range of fundamental processes. In this article, we outline the features of yeast that have similarly been exploited for undergraduate research training. We selected examples from published literature that demonstrate the utility of the yeast system for research-based learning embedded in the curriculum. We further describe a project which we designed for the team-based final-year dissertation projects module on our transnational joint programme, which investigates whether the expression and functions of the budding yeast RPL36 ribosomal protein paralogs are influenced by the overlapping long non-coding RNA genes. Students carry out the experimental procedures in a 2-week timetabled teaching block and exercise widely applicable biochemical techniques, including aseptic yeast cell culture and sample collection, RNA isolation, qRT-PCR quantitation, protein extraction and Western blot analysis, and cell cycle progression patterns using light microscopy and flow cytometry. It is challenging to design training programmes for undergraduates that are meaningful as well as practical and economical, but it is possible to transform active research projects into authentic research experiences. We consider yeast to be an ideal model organism for such projects. These can be adapted to the constraints of course schedules and explore fundamental biochemical topics which are evolutionarily conserved from yeast to mammals.

Evaluating two steps in transcription using a fluorescence-based electrophoretic mobility shift assay

Transcription is the critical first step in expressing a gene, during which an RNA polymerase (RNAP) synthesizes an RNA copy of one strand of the DNA that encodes a gene. Here we describe a laboratory experiment that uses a single assay to probe two important steps in transcription: (1) RNAP binding to DNA, and (2) the transcriptional activity of the polymerase. Students probe both these steps in a single experiment using a fluorescence-based electrophoretic mobility shift assay (EMSA) and commercially available Escherichia coli RNAP. As an inquiry-driven component, students add the transcriptional inhibitor rifampicin to reactions and draw conclusions about its mechanism of inhibition by determining whether it blocks polymerase binding to DNA or transcriptional activity. Depending on the curriculum and learning goals of individual courses, this experimental module could be easily expanded to include additional experimentation that mimics a research environment more closely. After completing the experiment students understand basic principles of transcription, mechanisms of inhibition, and the use of EMSAs to probe protein/DNA interactions.

Combining 3D-Printed Models and Open Source Molecular Modeling of p53 To Engage Students with Concepts in Cell Biology

While understanding macromolecular structural elements and their roles in dictating cellular function is critical to grasp basic concepts in biology, it can be challenging for students to master this content—these elements naturally exist at the nanoscale and are not observable with the naked eye. Oftentimes this understanding is catalyzed by impactful illustrations and animations found online and in textbooks. In recent years, 3D printing technology has become readily accessible as an additional way to generate models and visualize entities of interest. In this report, we describe and discuss the efficacy of an approach using 3D-printed models in combination with online open-source molecular modeling analyses of the macromolecular structure of p53 to engage students with molecular concepts in cancer cell biology and human health. This pedagogy strategy has been successfully integrated into an upper-level undergraduate course at a primarily undergraduate institution and a graduate biology course at a public research university. We describe the potential benefits while providing tools for others to integrate this strategy into their teaching.

TP53 germline mutations in the context of families with hereditary breast and ovarian cancer: a clinical challenge

Purpose

TP53germline (g) mutations, associated with the Li-Fraumeni syndrome (LFS), have rarely been reported in the context of hereditary breast and ovarian cancer (HBOC). The prevalence and cancer risks in this target group are unknown and counseling remains challenging. Notably an extensive high-risk surveillance program is implemented, which evokes substantial psychological discomfort. Emphasizing the lack of consensus about clinical implications, we aim to further characterize TP53g mutations in HBOC families.

Methods

Next-generation sequencing was conducted on 1876 breast cancer (BC) patients who fulfilled the inclusion criteria for HBOC.

Results

(Likely) pathogenic variants in TP53 gene were present in 0.6% of the BC cohort with higher occurrence in early onset BC < 36 years. (1.1%) and bilateral vs. unilateral BC (1.1% vs. 0.3%). Two out of eleven patients with a (likely) pathogenic TP53g variant (c.542G > A; c.375G > A) did not comply with classic LFS/Chompret criteria. Albeit located in the DNA-binding domain of the p53-protein and therefore revealing no difference to LFS-related variants, they only displayed a medium transactivity reduction constituting a retainment of wildtype-like anti-proliferative functionality.

Conclusion

Among our cohort of HBOC families, we were able to describe a clinical subgroup, which is distinct from the classic LFS-families. Strikingly, two families did not adhere to the LFS criteria, and functional analysis revealed a reduced impact on TP53 activity, which may suit to the attenuated phenotype. This is an approach that could be useful in developing individualized screening efforts for TP53g mutation carrier in HBOC families. Due to the low incidence, national/international cooperation is necessary to further explore clinical implications. This might allow providing directions for clinical recommendations in the future.

Electronic supplementary material

The online version of this article (10.1007/s00404-020-05883-x) contains supplementary material, which is available to authorized users.

In silico Phage Hunting: Bioinformatics Exercises to Identify and Explore Bacteriophage Genomes

Bioinformatics skills are increasingly relevant to research in most areas of the life sciences. The availability of genome sequences and large data sets provide unique opportunities to incorporate bioinformatics exercises into undergraduate microbiology courses. The goal of this project was to develop a teaching module to investigate the abundance and phylogenetic relationships amongst bacteriophages using a set of freely available bioinformatics tools. Computational identification and examination of bacteriophage genomes, followed by phylogenetic analyses, provides opportunities to incorporate core bioinformatics competencies in microbiology courses and enhance students’ bioinformatics skills. The first activity consisted of using PHASTER (PHAge Search Tool Enhanced Release), a bioinformatics tool that identifies bacteriophage sequences within bacterial chromosomes. Further computational analyses were conducted to align bacteriophage proteins, genomes, and determine phylogenetic relationships amongst these viruses. This part of the project was carried out using the Clustal omega, MAFFT (Multiple Alignment using Fast Fourier Transform), and Interactive Tree of Life (iTOL) programs for sequence alignments and phylogenetic analyses. The laboratory activities were field tested in undergraduate directed research, and microbiology classes. The learning objectives were assessed by comparing the scores of pre and post-tests and grading final presentations. Post-tests were higher than pre-test scores at or below p = 0.002. The data suggest in silico phage hunting improves students’ ability to search databases, interpret phylogenetic trees, and use bioinformatics tools to examine genome structure. This activity allows instructors to integrate key bioinformatic concepts in their curriculums and gives students the opportunity to participate in a research-directed learning environment in the classroom.

Bacterial cellobiose metabolism: An inquiry-driven, comprehensive undergraduate laboratory teaching approach to promote investigative learning

Technique-centered biochemistry or molecular biology undergraduate laboratory curricula do not offer significant opportunities for thoughtful, in-depth exploration of the science to foster investigative learning. To demonstrate inclusion of inquiry-driven laboratory experiments into the undergraduate biochemistry and molecular biology curricula, a comprehensive set of laboratory experiments, covering several principles of biochemistry and molecular biology, have been developed under a single theme. The laboratory curriculum described here comprehensively investigates bacterial cellobiose metabolism using multiple biochemical, molecular biological (RNA isolation, RT-PCR, PCR, and enzyme assay), and analytical techniques (High Performance Liquid Chromatography, NMR, spectrophotometry, and thin-layer chromatography) to explore the principles of metabolomics and genomics in a single undergraduate laboratory course setting using Caulobacter crescentus as the model organism. This laboratory module serves as a model for educators to develop easy-to-implement laboratory curricula incorporating contemporary biochemistry and molecular biology concepts and techniques to provide a course-based undergraduate research experiences (CUREs) with defined learning objectives. © 2019 International Union of Biochemistry and Molecular Biology, 47(4):438-445, 2019.

An undergraduate laboratory experience using CRISPR-cas9 technology to deactivate green fluorescent protein expression in Escherichia coli

Undergraduates learn that gene editing in diverse organisms is now possible. How targeted manipulation of genes and genomes is utilized in basic science and biomedicine to address biological questions is challenging for undergraduates to conceptualize. Thus, we developed a lab experience that would allow students to be actively engaged in the full process of design, implementation of a gene editing strategy, and interpretation of results within an 8-week lab period of a Genetics course. The laboratory experience combines two transformative biotechnology tools; the utilization of green fluorescent protein (GFP) as a diagnostic marker of gene expression and the fundamentals and specificity of Clustered Regularly Interspaced Short Palindromic Repeats-cas9 (CRISPR-cas9) gene editing in bacterial cells. The students designed and constructed plasmids that express single guide RNA targeted to GFP, expressed the sgRNA and cas9 in bacteria cells, and successfully deactivated GFP gene expression in the bacterial cells with their designed CRISPR-cas9 tools. Student assessment revealed most students achieved student learning objectives. We conclude this lab experience is an effective and accessible method for engaging students in the scientific practices, knowledge and challenges revolving targeted CRISPR-cas9 gene manipulation. © 2019 International Union of Biochemistry and Molecular Biology, 47(2): 145-155, 2019.

Anticipated learning outcomes for a biochemistry course-based undergraduate research experience aimed at predicting protein function from structure: Implications for assessment design

Several course-based undergraduate research experiences (CUREs) have been published in the literature. However, only limited attempts have been made to rigorously identify the discovery-type research abilities that students actually develop during such experiences. Instead, there has been a greater focus on technical or procedural-type knowledge or general CURE skills that are too comprehensive to effectively assess. Before the extent of discovery-type learning outcomes can be established in students (termed verified learning outcomes or VLOs), it is important to rigorously identify the anticipated learning outcomes (ALOs) and to then develop student assessments that target each ALO to reveal the nature of such student learning. In this article we present a matrix of 43 ALOs, or course-based undergraduate research abilities (CURAs), that instructors anticipate students will develop during a recently-developed biochemistry CURE focusing on the prediction of protein function from structure. The CURAs were identified using the process for identifying course-based undergraduate research abilities (PICURA) and classified into seven distinct themes that enabled the characterization of the CURE and a comparison to other published inventories of research competencies and CURE aspects. These themes and the CURE protocols aligning to the CURAs were used to form the ALO matrix that was, in turn, used to inform the design of an assessment that revealed evidence that a student had developed some of the targeted CURAs. Future research will focus on further assessment development that targets other identified CURAs. This approach has potential applications to other CUREs both in biochemistry and other science disciplines. © 2018 International Union of Biochemistry and Molecular Biology, 46(5):478-492, 2018.

Course-based undergraduate research experiences in molecular biosciences-patterns, trends, and faculty support

Inquiry-driven learning, research internships and course-based undergraduate research experiences all represent mechanisms through which educators can engage undergraduate students in scientific research. In life sciences education, the benefits of undergraduate research have been thoroughly evaluated, but limitations in infrastructure and training can prevent widespread uptake of these practices. It is not clear how faculty members can integrate complex laboratory techniques and equipment into their unique context, while finding the time and resources to implement undergraduate research according to best practice guidelines. This review will go through the trends and patterns in inquiry-based undergraduate life science projects with particular emphasis on molecular biosciences-the research-aligned disciplines of biochemistry, molecular cell biology, microbiology, and genomics and bioinformatics. This will provide instructors with an overview of the model organisms, laboratory techniques and research questions that are adaptable for semester-long projects, and serve as starting guidelines for course-based undergraduate research.

Pathways over Time: Functional Genomics Research in an Introductory Laboratory Course

National reports have called for the introduction of research experiences throughout the undergraduate curriculum, but practical implementation at many institutions faces challenges associated with sustainability, cost, and large student populations. We describe a novel course-based undergraduate research experience (CURE) that introduces introductory-level students to research in functional genomics in a 3-credit, multisection laboratory class. In the Pathways over Time class project, students study the functional conservation of the methionine biosynthetic pathway between divergent yeast species. Over the five semesters described in this study, students (N = 793) showed statistically significant and sizable growth in content knowledge (d = 1.85) and in self-reported research methods skills (d = 0.65), experimental design, oral and written communication, database use, and collaboration. Statistical analyses indicated that content knowledge growth was larger for underrepresented minority students and that growth in content knowledge, but not research skills, varied by course section. Our findings add to the growing body of evidence that CUREs can support the scientific development of large numbers of students with diverse characteristics. The Pathways over Time project is designed to be sustainable and readily adapted to other institutional settings.

Define Your Goals Before You Design a CURE: A Call to Use Backward Design in Planning Course-Based Undergraduate Research Experiences

We recommend using backward design to develop course-based undergraduate research experiences (CUREs). The defining hallmark of CUREs is that students in a formal lab course explore research questions with unknown answers that are broadly relevant outside the course. Because CUREs lead to novel research findings, they represent a unique course design challenge, as the dual nature of these courses requires course designers to consider two distinct, but complementary, sets of goals for the CURE: 1) scientific discovery milestones (i.e., research goals) and 2) student learning in cognitive, psychomotor, and affective domains (i.e., pedagogical goals). As more undergraduate laboratory courses are re-imagined as CUREs, how do we thoughtfully design these courses to effectively meet both sets of goals? In this Perspectives article, we explore this question and outline recommendations for using backward design in CURE development.