Teri J. Orr

Bats host a wide range of viruses, including several high-profile pathogens of humans and other animals. The COVID-19 pandemic raised the level of concern regarding the risk of spillover of bat-borne viruses to humans and, conversely, human-borne viruses to bats. From August 2020 to July 2021, we conducted viral surveillance on 254 bats from 10 species across urban, periurban, and rural environments in New Mexico, USA. We used a pan-coronavirus RT-PCR to assay rectal swabs and performed metagenomic sequencing on a representative subset of 14 rectal swabs and colon samples. No coronaviruses were detected by either RT-PCR or metagenomic sequencing. However, four novel viruses were identified: an adenovirus (proposed name lacepfus virus, LCPV), an adeno-associated virus (AAV), an astrovirus (AstV), and a genomovirus (GV). LCPV, detected in a big brown bat (Eptesicus fuscus), is more closely related to canine adenoviruses than to other bat adenoviruses, suggesting historical transmission between bats and dogs. All virus-positive bats were either juvenile or adult individuals captured in urban environments; none exhibited obvious clinical signs of disease. Our findings suggest limited or no circulation of enzootic coronaviruses or SARS-CoV-2 in southwestern U.S. bat populations during the study period. The discovery of a genetically distinct adenovirus related to canine adenoviruses highlights the potential for cross-species viral transmission and underscores the value of continued virome surveillance in animals living with and near humans.

Herbivores are frequently exposed to potentially toxic doses of plant secondary metabolites (PSMs). Furthermore, the plant species available and their associated PSMs may change over extended time periods. To understand the ability of herbivores to biotransform novel PSMs, we investigated populations of one species of mammalian herbivore that had undergone a radical diet shift, i.e., the desert woodrat’s (Neotoma lepida) switch juniper (Juniperus spp) to creosote bush (Larrea tridentata). To determine whether woodrats currently feeding on creosote also retain the ability to consume and biotransform the PSMs in their ancestral diet of juniper, we compared various metrics of hepatic biotransformation in a population that ingests creosote bush (Mojave woodrats) to one that specializes on the ancestral diet of juniper (Great Basin woodrats). We investigated PSM biotransformation capabilities by quantifying the hepatic metabolism of α-pinene, a common terpene in juniper. We also measured total cytochrome P450 content, cytochrome P450 2B (CYP2B) and glutathione S-transferase (GST) concentrations, and the activity of GST in the livers of both populations consuming control (rabbit chow) and juniper diets. There were no differences in hepatic metabolism of α-pinene, total P450 content, or CYP2B concentration between woodrat populations when feeding on juniper. The only difference found was that the Mojave woodrats had higher GST activity compared to the Great Basin woodrats when feeding on juniper. Our results suggest that despite the change to a novel toxic diet, the Mojave woodrats maintain the capacity to metabolize their ancestral diet of juniper.

How mammalian herbivores evolve to feed on chemically defended plants remains poorly understood. In this study, we investigated the adaptation of two species of woodrats ( Neotoma lepida and N. bryanti ) to creosote bush ( Larrea tridentata ), a toxic shrub that expanded across the southwestern United States after the Last Glacial Maximum. We found that creosote-adapted woodrats have elevated gene dosage across multiple biotransformation enzyme families. These duplication events occurred independently across species and substantially increase expression of biotransformation genes, especially within the glucuronidation pathway. We propose that increased gene dosage resulting from duplication is an important mechanism by which animals initially adapt to novel environmental pressures.

Synopsis: Trade-offs during reproduction have long been a central focus within biology and much of the foundational work within life history evolution has focused on females, as the fitness of females is more easily quantified for use in theoretical models. However, in many regards, the field of organismal biology has deviated from this early focus on females, particularly as it relates to the nuances and dynamic nature of female reproduction. Regardless, at the organismal level, reproduction is thought to trade-off with other simultaneously occurring processes. Recent papers have sought to outline the issues with our current understanding of whole-organism trade-offs, though the field as a whole has not come to a consensus on what trade-offs mean to a reproducing female. To rectify this important gap in how trade-offs are discussed in organismal biology as well as confusion about what constitutes a trade-off, our overarching goal of this symposium was to discuss trade-offs from an integrative perspective that places female reproduction at the center. By answering what trade-offs are and what they mean to reproducing females, what has been neglected in the context of whole-organism physiology, and how maternal effects fit within this framework, our group of speakers and their associated papers will crystalize nuances of measuring and determining presence (if any) of trade-offs in reproducing females in a range of taxa and subfields.

Synopsis: Trade-offs resulting from the high demand of offspring production are a central focus of many subdisciplines within the field of biology. Yet, despite the historical and current interest on this topic, large gaps in our understanding of whole-organism trade-offs that occur in reproducing individuals remain, particularly as it relates to the nuances associated with female reproduction. This volume of Integrative and Comparative Biology (ICB) contains a series of papers that focus on reviewing trade-offs from the female-centered perspective of biology (i.e., a perspective that places female reproductive biology at the center of the topic being investigated or discussed). These papers represent some of the work showcased during our symposium held at the 2024 meeting of the Society for Integrative and Comparative Biology (SICB) in Seattle, Washington. In this roundtable discussion, we use a question-and-answer format to capture the diverse perspectives and voices involved in our symposium. We hope that the dialogue featured in this discussion will be used to motivate researchers interested in understanding trade-offs in reproducing females and provide guidance on future research endeavors.

There is much current debate in the US regarding how sex and gender are approached in science and medical classrooms. There does not seem to be sufficient consensus around why it must be taught and how it should be implemented. State-enacted restrictions to both education and healthcare in recent years demonstrate the relevance and importance of sex and gender in the college classroom, not only including but especially in the biology classroom. Given the areas comprising the Society for Integrative and Comparative Biology (SICB), these topics of sex and gender in biology instruction are incredibly salient to our members. Thus, this survey aimed to determine instructors’ views of and experiences with sex-diverse gender-inclusive biology. College-level biology instructors who are members of SICB were surveyed about their views of science, views of sex and gender, teaching philosophy, and their experiences with inclusive teaching and with sex-diverse gender-inclusive teaching. The resulting data lead us to implore academic biology to provide more sex-diverse and gender-inclusive teaching tools and resources to educators, while minimizing potential fear of retaliation and backlash to instructors who utilize these teaching methods.

Synopsis: Inclusive teaching is teaching in a way that reaches all students in the classroom; this is beneficial for everyone, particularly for those with minoritized identities. Instructors play a critical role in scaffolding how students are exposed to and learn science content in the classroom. In this manuscript, we discuss how biology instructors can make their classrooms more inclusive with regard to sex and gender diversity content. Many topics in biology are based on androcentric, heteronormative, and oppressive framing, even though those lenses are more reflective of our own history and culture than they are of the diversity we see in nature. Here, we summarize information presented in the SICB 2024 workshop titled “Incorporating sex diversity and gender inclusivity in biology undergraduate classrooms” and provide instructors with (a) rationale for why inclusive teaching matters, (b) guidance on how to challenge unscientific views and make their curricula more sex diverse and gender inclusive, and (c) practical and easy-to-implement strategies for discussing “contentious” topics in the classroom. Incorporation of this material will be beneficial for students, for science and medicine, and for accurately representing the diversity found across the tree of life.

The genomic architecture underlying the origins and maintenance of biodiversity is an increasingly accessible feature of species, due in large part to third‐generation sequencing and novel analytical toolsets. Applying these techniques to woodrats (Neotoma spp.) provides a unique opportunity to study how herbivores respond to environmental change. Neotoma bryanti and N. lepida independently achieved a major dietary feat in the aftermath of a natural climate change event: switching to the novel, toxic food source creosote bush (Larrea tridentata). To better understand the genetic mechanisms underlying this ability, we employed a trio binning sequencing approach with a N. bryanti × N. lepida F₁ hybrid, allowing the simultaneous assembly of genomes representing each parental species. The resulting phased, chromosome‐level, highly complete haploid references enabled us to explore the genomic architecture of several gene families—cytochromes P450, UDP‐glucuronosyltransferases (UGTs), and ATP‐binding cassette (ABC) transporters—known to play key roles in the metabolism of naturally occurring toxic dietary compounds. In addition to duplication events in the ABCG and UGT2B subfamilies, we found expansions in three P450 gene families (2A, 2B, 3A), including the evolution of multiple novel gene islands within the 2B and 3A subfamilies, which may have provided the crucial substrate for dietary adaptation. Our assemblies demonstrate that trio binning from an F₁ hybrid rodent effectively recovers parental genomes from species that diverged more than a million years ago.

Synopsis: The lower reproductive tract of female mammals has several competing functions including mating, tract health maintenance, and parturition. Diverse vaginal anatomy suggests interactions between natural and sexual selection, yet despite its importance, female copulatory morphology remains under-studied. We undertook a comparative study across the species-rich mammalian order Chiroptera (bats) with a focus on the suborder Yangochiroptera (Vespertilioniformes) to examine how female vaginal features may have coevolved with male penis morphology to minimize mechanical damage to their tissues during copulation. The penis morphology is diverse, presenting great potential for post-copulatory sexual selection and coevolution with the female morphology, but vaginas have not been carefully examined. Here we test the hypotheses that vaginal thickness and collagen density have coevolved with features of the male penis, including the presence of spines and a baculum. We present histological data from females of 24 species from 7 families of bats, and corresponding data on male penis anatomy. We also examine the role of phylogenetic history in the morphological patterns we observe. We found evidence that female vaginal thickness has coevolved with the presence of penile spines, but not with baculum presence or width. Collagen density did not appear to covary with male penile features. Our findings highlight the importance of considering interactions between the sexes in influencing functional reproductive structures and examine how these structures have been under selection in bats.