Enhancing the Mentoring Experience for Underrepresented Students.

Undergraduate research is a valuable experience that increases the likelihood of a STEM major to continue on to postgraduate training in their field. For students from groups underrepresented in the biomedical sciences, a strong mentoring relationship during this undergraduate period is a key component in preparing them for the next stage of their education and can have a significant influence on their ability to persist in the pipeline. Although the ideal scenario to increase the diversity of the biomedical workforce is to provide more BIPOC (Black, Indigenous, People of Color) faculty mentors for our undergraduates, we also need to develop strategies to provide strong mentoring experiences for our BIPOC students when those mentors are not in great number. At Xavier University of Louisiana, we have used our NIH BUILD Project Pathways program to look more closely at the mentor matching process. Throughout the past seven years, we have moved from the traditional mentor, research-focused matching process to a student-centered process. The lessons learned here can be used by any University looking to craft an inclusive undergraduate research program to meet the needs of all students, but in particular a diverse student population.

Novel flanking DNA sequences enhance FOXO1a DNA binding affinity but do not alter DNA bending.

FOXO1A, a member of the forkhead winged-helix family of proteins is a transcription factor with proapoptotic activities and plays a significant role in insulin and growth factor signaling. As such, FOXO1A is insulin responsive and binds to the insulin response element (IRE). However, multiple forkhead family members with diverse biological functions are also known to bind to the IRE. Therefore, additional DNA sequence elements may be required to provide increased binding affinity and specificity for FOXO1A. We have used the systematic evaluation of ligands by exponential enrichment (SELEX) to systematically identify additional DNA sequences important for FOXO1A binding. We demonstrate for the first time that, in addition to the IRE, two additional sequence elements are important for maximal FOXO1A binding: (1) the reverse complement (5'-GT(A/C)AACA-3') and (2) the flanking sequence (5'-ACAACA-3'). Although these additional elements do not contribute to the FOXO1A-induced DNA bending angle of 120 degrees , the presence of these additional elements does increase the affinity of FOXO1A DNA binding nearly 9-fold through a 1-to-1 binding stoichiometry. The increased binding affinity subsequently enhances the ability of FOXO1A to activate transcription from a luciferase reporter construct and from promoter regions of endogenous genes known to be direct transcriptional targets of FOXO1A.

Inquiry-based experiments for large-scale introduction to PCR and restriction enzyme digests.

Polymerase chain reaction and restriction endonuclease digest are important techniques that should be included in all Biochemistry and Molecular Biology laboratory curriculums. These techniques are frequently taught at an advanced level, requiring many hours of student and faculty time. Here we present two inquiry-based experiments that are designed for introductory laboratory courses and combine both techniques. In both approaches, students must determine the identity of an unknown DNA sequence, either a gene sequence or a primer sequence, based on a combination of PCR product size and restriction digest pattern. The experimental design is flexible, and can be adapted based on available instructor preparation time and resources, and both approaches can accommodate large numbers of students. We implemented these experiments in our courses with a combined total of 584 students and have an 85% success rate. Overall, students demonstrated an increase in their understanding of the experimental topics, ability to interpret the resulting data, and proficiency in general laboratory skills.

Purification and characterization of enzymes from yeast: an extended undergraduate laboratory sequence for large classes.

Providing a project-based experience in an undergraduate biochemistry laboratory class can be complex with large class sizes and limited resources. We have designed a 6-week curriculum during which students purify and characterize the enzymes invertase and phosphatase from bakers yeast. Purification is performed in two stages via ethanol precipitation and anion exchange chromatography, and students perform both direct and coupled enzyme assays. By completion of the experimental series, students are able to identify which enzymes they have purified and have obtained kinetic parameters for one. This experimental series requires minimal instructor preparation time, is cost effective, and works with multiple sections of large groups of students. Students participating in this sequence showed increases in conceptual understanding of biochemical concepts as measured through in-class assessments and anonymous surveys.