Biology and Health Science Research

May 2022 - May 2023

Michelle Thompson and Dr. Rebecca Flaherty

Analysis of Macrophage Cell Death in Response to Diverse Group B Streptococcus Isolates
Michelle Thompson

Group B Streptococcus (GBS) is a leading cause of preterm birth, stillbirth, and neonatal sepsis and meningitis worldwide [1–3].  It is a common resident of the genitourinary tract in approximately 40% of pregnant women and is a risk factor for preterm birth and neonatal disease [1–3].  In order to develop effective treatment and diagnostic strategies, there is a critical need to understand how GBS interacts with human tissues to induce inflammation, invade the extraplacental membranes, and harm the fetus or newborn.  Macrophages are a key immune system cell type that play critical roles at the maternal-fetal interface during pregnancy as well as in the immune system of newborn infants.  Our lab and others have previously identified differences in macrophage cell death in response to different GBS strains of varying virulence [4-5].  A key goal of this project will be to explore the type of cell death that is being induced in these macrophages following GBS infection with these diverse strains and to explore some of the macrophage signaling pathways that regulate these responses.

Faculty Advisor: Dr. Rebecca Flaherty
Funded by: Mohler-Thompson Summer Research Grant

Dr. Rebecca Penny Humphrey and Sydney Shenk

Influence of pollen aperture number on germination and pollen tube length in Thalictrum dasycarpum, an in vivo study with fluorescence microscopy
Sydney Shenk

We will be continuing a line of past research to assess the influence of pollen aperture number on germination likelihood and timing and pollen tube length in Thalictrum dasycarpum, a wind-pollinated species. Using plants cultivated within the Aquinas College greenhouse, we plan to develop methods for fluorescence microscopy to observe pollen germination in vivo and to optimize our in vitro pollen-germination method for this species. We will also investigate the following parallel questions: What is the influence of stigmatic pollen load on pollen germination rate? How reliable are standard methods in determining actual pollen loads (i.e., how much pollen is lost in processing?)? Given time and methodological success, we will consider the influence of pollen load on the relative success of different pollen aperture morphs.

Faculty Advisor: Dr. Rebecca Penny Humphrey
Funded by: Mohler-Thompson Summer Research Grant

May 2021 - May 2022

Deleon FlahertyUnderstanding the Role of the PI3K-Akt Pathway in the Macrophage Response to Group B Streptococcus (GBS)
Yadira DeLeon-Lopez

Group B Streptococcus (GBS) can be part of a healthy individuals' microbial flora. However, problems may arise when a mother, who is colonized with GBS, becomes pregnant. As the fetus develops within the colonized mother, severe GBS infections may occur due to the limited capabilities of the developing fetal immune response. This may lead to the fetus becoming ill with meningitis, pneumonia, or sepsis, which may lead to death. The goal of this project is to understand how GBS manipulates cell signaling within macrophages in order to survive and cause disease. Specifically, we will investigate whether the PI3K/Akt pathway plays a role in three key aspects of the macrophage response to GBS infection. Our first aim will investigate why certain strains of GBS are engulfed by macrophages more rapidly than others. Next, we will evaluate how certain GBS strains survive more successfully within macrophages following phagocytosis. Lastly, we will compare the rate of survival of the macrophages themselves following infection with the different GBS strains. Our primary methods of analysis will include Western Blotting, fluorescence microscopy, and colony counting assays. This research may provide new insights for the development of diagnostic and therapeutic tools to combat GBS.

Faculty Advisor: Rebecca Flaherty
Funded by: Mohler-Thompson Summer Research Grant

Bouyac HumphreyInfluence of aperture number on pollen grain viability and germination in Thalictrum dasycarpum
Flore Bouyac

Pollen heteromorphism, the presence of multiple types of fertile pollen grains within all individuals of a population, is ubiquitous in the flowering-plant genus Thalictrum. Our aim is to investigate the selective regime influencing pollen-grain aperture number and whether this pattern differs among species/modes of pollination. We will observe pollen germination in vitro to measure aperture-number variation and timing and likelihood of germination within and among individuals of a wind-pollinated species, Thalictrum dasycarpum. Comparing our results to previous work on the insect-pollinated T. thalictroides, will bring us closer to both a universal understanding of the influence of aperture number on pollen grain fitness as well as how that relationship is altered by evolution in the mode of pollen transmission. Further, this study will provide insight into the evolution and maintenance of pollen heteromorphism.

Faculty Advisor: Rebecca Humphrey
Funded by: Mohler-Thompson Summer Research Grant

May 2020 - May 2021


Influence of pollination mode on stigmatic pollen loads in Thalictrum
Teegan Galdeen

Each pollen grain is a multicellular individual upon which environmental selective pressures may act. One environment experienced by all pollen grains is the size of the stigmatic pollen load, which is assumed to differ between wind- and insect-pollinated species. To determine how pollination mode is related to the selective pressures experienced by individual grains, we will analyze previously collected data on pollen loads in wind- and insect-pollinated Thalictrum species. Specifically, we will test the hypothesis that stigmatic pollen loads in insect-pollinated species are significantly higher than in wind-pollinated Thalictrum species. We plan to write a manuscript about this project for submission to a peer-reviewed publication. We will also be studying R programming, light- and fluorescence-microscopy techniques, and in vivo pollen staining protocols.

Faculty Advisor: Dr. Rebecca Humphrey
Funded by: Mohler-Thompson Summer Research Grant

Investigation of coral-dinoflagellate symbiosis - literature review (if we get access to lab, we will use the Aiptasia model system)
Lucas Topie

We will review the existing literature to identify proteins suspected to be involved in coral-dinoflagellate symbiosis, with a particular focus on innate immune receptors expressed by the coral host. We will focus on cnidarian host proteins that may mediate recognition and/or uptake of the dinoflagellate by the coral host. If we have access to the lab later in the summer, we plan to isolate cDNA coding for proteins of interest from Aiptasia (a model cnidarian) and clone these genes into suitable expression vectors. We will write a review of research published on the recognition and uptake of dinoflagellates by the coral host with a focus on work published since the 2012 review by Davy et al "Cell Biology of Cnidarian-Dinoflagellate Symbiosis"

Faculty Advisor: Larry Robert Peters PhD
Funded by: Mohler-Thompson Summer Research Grant

May 2019 - May 2020

Peters Djirackor

Constructing tools to study the role of an innate immune receptor (Nod1) in hematopoietic stem cell development
Svetlana Djirackor and Lucas Topie

We will subclone zebrafish dominant negative Nod1 alleles our group formerly designed. These subcloned alleles will be used by our collaborators to advance hematopoietic stem cell research. The zebrafish model was chosen due to its ease of use in large-scale applications, chemical screens and in vivo imaging.

Faculty Advisor: L. Rob Peters
Funded by: Mohler-Thompson Summer Research Grant

Humphrey Graham

Relationship between pollen aperture number and germination in Thalictrum
Spencer Graham

Pollen heteromorphism is a characteristic belonging to certain species of plants in which an individual produces multiple types of fertile pollen grains. It is possible that certain pollen morphs are inherently more viable than others. We would like to observe pollen germination in vitro in order to measure morphological variation and efficiency of germination within and among individuals of multiple populations and species of Thalictrum. This study will provide insight into the evolution of pollen heteromorphism.

Faculty Advisor: Rebecca Penny Humphrey
Funded by: Mohler-Thompson Summer Research Grant

The Dessication Tolerance of Craterostigma plantagineum
Michael Kalinowski

We studied the genetic basis of the dehydration tolerance of Craterostigma plantagineum, a small plant from South Africa. We utilized RNA-seq to trace RNA expression of the leaf and root tissues as the plant went through the desiccation cycle, and rehydrated. This work was mainly exploratory in nature, as this plant has never before been examined in this way.

Faculty Advisor: Robert VanBuren, Michigan State University
Funded by: NSF-funded

May 2018 - May 2019

Bringing Biodiversity to Restored Grasslands
Dana VanHuis

Our project focuses on grassland management. We are looking at five different grasslands (four at PCCI and one in Grand Rapids). Each grassland is either being burned, mowed, or left un-managed. We are then studying the biodiversity indexes of birds, insects, and vegetation in each of these fields to determine which management technique fosters the greatest levels of biodiversity. Hopefully through this study, a model can be made for other organizations and landowners that can be used to move restored grasslands from tallgrass monocultures to diverse and thriving grasslands.

Faculty Advisor: Dr. Rob Keys, Cornerstone University
Funded by: Pierce Cedar Creek Institute

Humphrey Clark WillsonAbiotic factors affecting prevalence of Rosa multiflora in Southwest Michigan
Alyssa Wilson and Stephanie Clark

Rosa multiflora, or multiflora rose, is an invasive plant species in the northeast and midwest United States. We are interested in quantifying the abiotic factors--such as soil pH and moisture, distance from trail, and sunlight availability--that contribute to the ability of multiflora rose to proliferate in some areas over others.

Stephanie Clark and Alyssa WillsonThe goal of this research is to provide land managers with information regarding which areas are most susceptible to multiflora rose invasion and establishment, specifically in Southwest Michigan.

Faculty Advisor: Dr. Rebecca Humphrey
Funded by: Pierce Cedar Creek Institute

Hess and Nowland

Investigating the Antibacterial Properties of Natural Substances
Gina Nowland

We will research natural antimicrobial substances and previously isolated soil bacteria. Previous research on natural antimicrobial substances indicated that allicin, a compound created from garlic when it is crushed, and eugenol, a compound from clove oil, are highly effective against bacteria such as Streptococcus mutans. An oral bacterium, S. mutans, is an organism that contributes to the formation of plaque and tooth decay. The growth and growth inhibition of S. mutans on mitis salivarius (MS) agar is being studied under aerobic and anaerobic conditions.

Gina NowlandThese conditions were put in place to replicate the growth of oral bacteria at night. The mouth, being closed, may decrease the amount of oxygen present to the bacteria making anaerobic conditions ideal to test how the growth of bacteria such as S. mutans could be affected. Individual bacteria isolated from soil samples collected during September 2017 will continue to be characterized and tested against ESKAPE pathogen safe relatives in the search for new antibiotics. Many of these bacterial isolates were previously found to be highly effective in inhibiting the growth of the ESKAPE pathogens.

May 2017 - May 2018

student researchers Utilizing the Gateway cloning technique for creation of Tol2 transposons containing wild type and mutant zebrafish NOD1 alleles.
Benjamin Arnson

NOD1 is an innate immune receptor involved in detecting cytosolic bacteria. We plan to subclone wild type (wt) and mutant (K202R) zebrafish NOD1 alleles into the plasmid pENTR1ADS. This will allow use of a Gateway cloning technique to make three different Tol2 transposons encoding the wt, K202R and L36Q NOD1 alleles, respectively. These transposons will allow our collaborators to make transgenic zebrafish in which NOD1 function can be controlled in a tissue-specific manner. The transgenic zebrafish will then be used to study the role of NOD1 in hematopoiesis (i.e., the development of blood cells).

Faculty Advisor: Dr. Rob Peters
Funded by: Mohler-Thompson Summer Research Grant

student researchers Design of the Riparian Buffer along Coldbrook Creek at Brookby Estate
Amanda Roth

Riparian buffers are areas of vegetation along the edge of water bodies; they provide protection for water bodies and habitat for organisms. The goal of this research project is to create an aesthetically pleasing buffer along Coldbrook Creek at the Brookby Estate to preserve the estate’s historic integrity while improving its environmental value. This project involves researching wildflower species that will thrive along the creek, growing these plants from seed, and installing them along the creek. Different plant propagation methods will be investigated to determine the best method for building a riparian buffer from seed.

Faculty Advisor: Dr. Rebecca Humphrey
Funded by: Mohler-Thompson Summer Research Grant

May 2016 - May 2017

Faculty Advisor: Dr. Jennifer Hess
Funded by: Mohler-Thompson Summer Research Grant

student researchers The Characterization of Bacteria Contaminants in Vitamins and Supplements 
Avery Wagner

A previous Mohler Thompson student found that a particular brand of garlic capsule was contaminated while testing its antimicrobial effects against a common bacteria found in dental plaque. We will attempt to characterize this contaminant through various staining techniques, selective and differential media tests, and some molecular biology. We will also test other vitamins and supplements for contaminants, including a new batch of the same brand of garlic capsule that had contaminants four years ago. 

Faculty Advisor: Jennifer Hess
Funded by: Mohler-Thompson Summer Research Grant

student researchers

Understanding the Endosymbiotic Relationship of Corals
Bridgette Degenhardt

This summer we will be studying the different genes involved in the endosymbiotic relationship between the anemone Aiptasia and the algae that live within it. Variables such as temperature, bleaching, and pH can be manipulated so that we may attempt to explore the different genetic responses within Aiptasia using qPCR. We hope to clone certain genes of interest into bacterial plasmids and eventually characterize their proteins to better understand the molecular and chemical relationship between corals and their endosymbionts. 

Faculty Advisor: LR Peters
Funded by: Mohler-Thompson Summer Research Grant