A deeper look into the morphology and receptors found in the tick (Acari: Ixodidae) chemoperception structure, the Haller's organ

The Haller's organ is a sensory structure unique to ixodid ticks that assists in host seeking behaviors. Presented here are the results of a detailed comparative study of the morphology and the chemoperception gene expression of the Haller’s organ. The morphometrics study focuses on the three important North American tick species: Ixodes scapularis, Amblyomma americanum, and Dermacentor variabilis. Possible differences in morphology between and within these species and between males and females for each species were observed using environmental scanning electron microscopy (ESEM). Analyses using geometric morphometrics resulted in low levels of intraspecific, within sex variation in the morphology of Haller’s organ and high variation between species. Differences between species may be due to different host seeking behaviors (passive versus active). The differences in Haller’s organ morphology of males and females of the same species could be attributed to post-mating behaviors. The exploration of chemoperception gene expression in the Haller’s organ focused on a single species, Ixodes scapularis. This study focused on the expression of ionotropic (IR) and gustatory receptors (GR) in the forelegs of male and female ticks. Additionally, two phylogenetic trees were created corresponding to each receptor type. The phylogenetic trees show the orthology between the tick ionotropic and gustatory receptors and the described insect chemoreceptors. There were two I. scapularis IRs expressed in the forelegs of these ticks and five GRs of interest. This research aids in providing an increase in our knowledge of the Haller’s organ. The Haller’s organ is critical to the performance ability of tick activities including host location. Therefore, improved knowledge of the Haller’s organ may facilitate tick management

Fourteen Recommendations to Create a More Inclusive Environment for LGBTQ+ Individuals in Academic Biology

Individuals who identify as lesbian, gay, bisexual, transgender, queer, and otherwise non-straight and/or non-cisgender (LGBTQ+) have often not felt welcome or represented in the biology community. Additionally, biology can present unique challenges for LGBTQ+ students because of the relationship between certain biology topics and their LGBTQ+ identities. Currently, there is no centralized set of guidelines to make biology learning environments more inclusive for LGBTQ+ individuals. Rooted in prior literature and the collective expertise of the authors who identify as members and allies of the LGBTQ+ community, we present a set of actionable recommendations to help biologists, biology educators, and biology education researchers be more inclusive of individuals with LGBTQ+ identities. These recommendations are intended to increase awareness of LGBTQ+ identities and spark conversations about transforming biology learning spaces and the broader academic biology community to become more inclusive of LGBTQ+ individuals

One tick closer to a better understanding of tick physiology and how to incorporate tick biology in a classroom

The black-legged tick, Ixodes scapularis (Acari: Ixodidae), transmits pathogens that can have detrimental effects on human and wildlife health. The pathogens that I. scapularis transmits include the causative agents of Lyme disease and Powassan virus disease. Due to various human impact factors such as global climate change, black-legged ticks have been expanding their range and establishing themselves in new areas, allowing them to encounter novel animal hosts as well as new diseases which could further impact human and wildlife health. While the ecology of the black-legged tick is well studied, its physiology is not, which may limit tick management success. This dissertation examines two important components of I. scapularis physiology: embryogenesis and host-seeking mechanisms. This dissertation also includes the development and examination of a high school-teaching unit focused on Ixodes scapularis and Lyme disease. Science education and the sharing of science to the general public is an important component of future tick management strategies. In Chapter 1, I provide background information about I. scapularis biology as well as give an overview of the Haller’s organ, which is the chemosensory structure found in ticks. In Chapter 2, I discuss a micro-computed tomography (MicroCT) scanning procedure I developed for examining the embryogenesis of the black-legged tick and document the full embryogenesis of I. scapularis. The development of the MicroCT scanning procedure consisted of a qualitative comparison of MicroCT scans of I. scapularis embryos at different development points using three different fixation methods. The scans at all three development points were compared to determine which of the fixation methods produced the most consistent images at the lowest cost. In this case, I found that using hot ethanol and dissolved iodine was the best method. I subsequently used this method to scan embryos every 24-hours starting from the time the eggs were laid until the ticks emerged as larvae. These scans revealed both internal and external development points throughout the embryogenesis such as when limbs form and when the Haller’s organ arises. This is the first documentation of I. scapularis embryogenesis and the third tick species to have its complete embryogenesis documented. In Chapter 3, I conducted a study aimed to identify the neurons associated with the black-legged tick’s Haller’s organ and what odors I. scapularis can detect using their Haller’s organ. Neuron identification was accomplished by puncturing sensilla within the Haller’s organ of female black-legged ticks and using the carbocyanine dye DiI to dye the neurons. Once the neurons were dyed they were visualized using fluorescent microscopy. Additionally, legs of female ticks were fixed and embedded in resin so that thin cross-sections of the leg could be observed using transmission electron microscopy. In order to determine what odors these ticks can detect, I attempted to use both an electrolegogram (ELG) and single-sensilla recordings (SSR) to obtain physiological recordings of neuron activity of the tick legs after exposure to various host odors. Although the ELG recordings were unsuccessful, the SSR recordings yielded recordings of the neuron activity of a single sensillum within the capsule aperture of the Haller’s organ. The odors that these ticks are able to detect were then used in a tick-choice behavioral assay in order to determine if ticks find these odors attractive or repulsive. These studies revealed key structures within the legs of I. scapularis which I suspect to be the neurons associated with the Haller’s organ. Additionally, I found that the large sensillum within the capsule aperture of the black-legged tick’s Haller’s organ is able to detect phenols. For the choice tests, of these phenols, I found that ticks exhibited repellent behavior when exposed to p-methylphenol, diluted at 10 µg/µL. In Chapter 4, I describe the development of a high school unit that is focused on I. scapularis and the spread of Lyme disease. The Lyme Disease unit development was guided by the Next Generation Science Standards (NGSS) and Framework, which Illinois recently adopted. The unit was presented to students in a way that included exposure to comics especially created to give instruction and introduce new material including the primary phenomenon of the unit: “Why are these kids getting sick and how can I stop the spread of the disease?”. After being presented with the phenomenon, students would act as scientists and use scientific data, extracted from published research that they analyzed to decide what line of questioning they wanted to follow. In addition to developing the unit, the unit was piloted by one teacher during three different school years. After each pilot trial, the unit was revised and student and teacher data were collected. These data were critically analyzed using qualitative and quantitative methods. Ultimately, the unit developed contained 16 lessons which encompassed 5 performance expectations, 9 practices, 5 Disciplinary Core Ideas, and 4 Cross-Cutting Concepts outlined in the NGSS and Framework. My analyses revealed that many of the revisions throughout the unit were beneficial to the unit and that overall students were able to successfully answer questions about tick biology, tick ecology, disease biology and human impact on disease biology. Additionally, students were able to develop models and apply their knowledge to new situations presented to them. Collectively, this dissertation addresses major gaps in tick physiology knowledge and demonstrates the importance of translating basic scientific research into truly educational teaching units.LimitedAuthor requested closed access (OA after 2yrs) in Vireo ETD syste

Fourteen Recommendations to Create a More Inclusive Environment for LGBTQ+ Individuals in Academic Biology

Individuals who identify as lesbian, gay, bisexual, transgender, queer, and otherwise nonstraight and/or non-cisgender (LGBTQ+) have often not felt welcome or represented in the biology community. Additionally, biology can present unique challenges for LGBTQ+ students because of the relationship between certain biology topics and their LGBTQ+ identities. Currently, there is no centralized set of guidelines to make biology learning environments more inclusive for LGBTQ+ individuals. Rooted in prior literature and the collective expertise of the authors who identify as members and allies of the LGBTQ+ community, we present a set of actionable recommendations to help biologists, biology educators, and biology education researchers be more inclusive of individuals with LGBTQ+ identities. These recommendations are intended to increase awareness of LGBTQ+ identities and spark conversations about transforming biology learning spaces and the broader academic biology community to become more inclusive of LGBTQ+ individuals

Chronicling the Journey of the Society for the Advancement in Biology Education Research (SABER) in its Effort to Become Antiracist: From Acknowledgement to Action

The tragic murder of Mr. George Floyd brought to the head long-standing issues of racial justice and equity in the United States and beyond. This prompted many institutions of higher education, including professional organizations and societies, to engage in long-overdue conversations about the role of scientific institutions in perpetuating racism. Similar to many professional societies and organizations, the Society for the Advancement of Biology Education Research (SABER), a leading international professional organization for discipline-based biology education researchers, has long struggled with a lack of representation of People of Color (POC) at all levels within the organization. The events surrounding Mr. Floyd’s death prompted the members of SABER to engage in conversations to promote self-reflection and discussion on how the society could become more antiracist and inclusive. These, in turn, resulted in several initiatives that led to concrete actions to support POC, increase their representation, and amplify their voices within SABER. These initiatives included: a self-study of SABER to determine challenges and identify ways to address them, a year-long seminar series focused on issues of social justice and inclusion, a special interest group to provide networking opportunities for POC and to center their voices, and an increase in the diversity of keynote speakers and seminar topics at SABER conferences. In this article, we chronicle the journey of SABER in its efforts to become more inclusive and antiracist. We are interested in increasing POC representation within our community and seek to bring our resources and scholarship to reimagine professional societies as catalyst agents towards an equitable antiracist experience. Specifically, we describe the 12 concrete actions that SABER enacted over a period of a year and the results from these actions so far. In addition, we discuss remaining challenges and future steps to continue to build a more welcoming, inclusive, and equitable space for all biology education researchers, especially our POC members. Ultimately, we hope that the steps undertaken by SABER will enable many more professional societies to embark on their reflection journeys to further broaden scientific communities