Maclura pomifera (Raf.) Schneid.

https://thekeep.eiu.edu/herbarium_specimens_byname/19975/thumbnail.jp

Maclura pomifera (Raf.) Schneid.

https://thekeep.eiu.edu/herbarium_specimens_byname/19975/thumbnail.jp

Fluidity and Inconstancy: Australian Bush Tomatoes as an Exemplar of Non-Normative Sex Expression

Solanum, a genus of ~1500 global species, is one of the more interesting plant groups in which to study reproductive biology and ecology. Overwhelmingly, species in this group express full cosexuality, where individual plants have flowers containing both fully-functioning “male” (staminate) and “female” (carpellate) organs. However, there have been multiple and widespread evolutionary transitions within the genus to non-normative variations on this ancestral condition. Australian bush tomatoes (ca. 40 species) are especially diverse in this regard, with uncommon variation and combinations of unisexuality and cosexuality -- including, most notably, two sexual systems known as dioecy (unisexual male or female flowers on separate plants) and andromonoecy (combinations of male and cosexual flowers on every plant). This commentary summarizes 40+ years of study and highlights some of the more intriguing observations/findings that make the bush tomatoes an ideal model system for examining plant sexual expression – including functionally “female” flowers (in which “male” organs are formed and pollen is produced, but that pollen serves only as a reward to pollinators and plays no other role in sexual reproduction), leaky “male” plants (in which “male” flowers sometimes express “female” function via functional pistils and thus become cosexual), the preponderance of vestigial opposite-sex organs in unisexual flowers, and species (such as the recently-described S. plastisexum) where variation in sexual expression is the norm rather than the exception

Investigation into the Genetic Provenance of Three Rare Plants with East-West Disjunction Patterns in Pennsylvania.

Rare plant conservation relies on an understanding of the natural history, biology and ecology, and real and potential threats to their populations to inform state regulations that serve to protect the species from extirpation. This work often involves extensive field surveys over several years to determine population sizes and whether those populations are seeing reductions in number of individuals necessary to maintain the genetic diversity within and between those populations. Species and populations with high genetic diversity are better equipped to withstand sudden changes to their habitats that derive from land use changes and changing climate. There are a variety of methods used to investigate population genetic diversity and next generation sequencing (NGS) methods allow for complete genomic coverage by analyzing single nucleotide polymorphisms (SNPs) and allowing for an estimation of population genetic parameters such as genetic variation (FST), the inbreeding coefficient (FIS), and heterozygosity (HO) (HE). Population genomic investigations of Baptisia australis, Chasmanthium latifolium, and Erigenia bulbosa, plant species at the edge of their ranges in Pennsylvania and disjunct distributions within the state were performed for this study. All three species exhibited lower than expected heterozygosity and, with the exception of Chasmanthium, high levels of inbreeding. This information was incorporated into conservation rank status assessments and climate change vulnerability indices using the NatureServe Conservation Status Rank Calculator and the Climate Change Vulnerability Index tools. As a result, state ranks for Chasmanthium and Erigenia require formally proposed changes to the Department of Conservation of Natural Resources. Likewise, management recommendations are given as guidance on the steps likely necessary to preserve and potentially increase the genetic diversity for all species. Through these investigations, a long-term partnership between the Pennsylvania Natural Heritage Program at Western Pennsylvania Conservancy and Bucknell University was developed through which a pipeline of undergraduate and graduate students were, and will be, trained in both field-based natural heritage methods and new, innovative ways address the conservation of rare plants in Pennsylvania and beyond

Cross-pollination: Building a Co-taught Course to Examine Art and Sex Through the Lens of Botany

Driven by overlapping interests in plants, art, and diversity in sex expression, Anna Kell (Department of Art and Art History) and Chris Martine (Department of Biology) developed a course that integrates the perspectives of a visual artist and a botanist. Art & Sex Through the Lens of Botany seeks to impart the importance of making connections across disciplines and the value of visual literacy across academic lines. The course introduces foundational concepts in each field and encourages students to integrate and explore these different systems of knowledge and their intersections. In addition to developing fluencies related to both general botany and studio art, the goal of the course is that students demonstrate a variety of new strengths including a) the ability to recognize, construct, and evaluate connections among different intellectual methods, ways of learning, and bodies of knowledge; b) the ability to identify the various parts of a flower and discuss their significance and role in sexual reproduction in plants; c) increased awareness of visual forms of communication, including artistic expression, data visualization, and observation; and d) a broader understanding of the role of sexuality in the science of biology and in the formation of cultural beliefs and biases

Lepidopteran Granivory Reduces Seed Counts in a Rare Species of Riparian Scour Prairies

In Pennsylvania Baptisia australis var. australis is found along only four waterways: the Allegheny River, Youghiogheny River, Clarion River, and Red Bank Creek. Because of its limited distribution and small number of extant populations, the species is considered state-threatened in Pennsylvania. In addition, the riparian prairie habitat that Pennsylvania Baptisia australis var. australis is restricted to is also in decline and considered vulnerable. Because of these conservation concerns, insights into the natural history of the taxon in the state is valuable and will inform conservation efforts. Field surveys and fruit collections along the Allegheny River and herbarium collections were used to investigate and document granivory in Pennsylvania Baptisia australis var. australis, a phenomenon recorded in other parts of the species\u27 range, but not previously reported on in Pennsylvania. Using a model of best fit, the number of seeds found in fruit was found to be significantly impacted by the presence of granivores. We also report that visual surveys of fruits in the field are found to be accurate assessments of the presence and potential impact of granivores. In turn, our results will inform the conservation and management of Baptisia australis var. australis populations in Pennsylvania and highlight the importance of field surveys in protecting threatened taxa

Natural History Collections: Teaching About Biodiversity Across Time, Space, and Digital Platforms

Natural history collections offer unique physical and virtual opportunities for formal and informal progressive learning. Collections are unique data in that they each represent a biological record at a single place and time that cannot be obtained by any other method. Collections-based experiences lead to an increased understanding of and substantive interaction with the living world. Global biological diversity and changes in that diversity are directly tracked through specimens in collections, regardless of whether changes are ancient or recent. We discuss how collections, specimens, and the data associated with them, can be critical components linking nature and scientific inquiry. Specimens are the basic tools for educating students and interested citizens through direct or virtual contact with the diversity of collections. Such interactions include instruction in a formal classroom setting, volunteering to gather and curate collections, and informal presentations at coffee shops. We emphasize how the recent surge in specimen-based digitization initiatives has resulted in unprecedented access to a wealth of biodiversity information and how this availability vastly expands the reach of natural history collections. The emergence of online databases enables scientists and the public to utilize the specimens and associated data contained in natural history collections to address global, regional, and local issues related to biodiversity in a way that was unachievable a decade ago

Differentiating inhibition selectivity and binding affinity of isocitrate dehydrogenase 1 variant inhibitors

Isocitrate dehydrogenase (IDH) 1/2 gain-of-function variants catalyze the production of the oncometabolite 2-hydroxyglutarate and are validated targets for leukemia treatment. We report binding and inhibition studies on 13 IDH1/2 variant inhibitors, including clinical candidates and drugs, with wild-type (wt) IDH1 and its cancer-associated variant, IDH1 R132H. Interestingly, all the variant inhibitors bind wt IDH1 despite not, or only weakly, inhibiting it. Selective inhibition of the IDH1 R132H variant over wt IDH1 does not principally relate to the affinities of the inhibitors for the resting forms of the enzymes. Rather, the independent binding of Mg2+ and 2-oxoglutarate to the IDH1 variant makes the variant more susceptible to allosteric inhibition, compared to the tighter binding of the isocitrate–Mg2+ complex substrate to wt IDH1. The results highlight that binding affinity need not correlate with inhibition selectivity and have implications for interpretation of inhibitor screening results with IDH and related enzymes using turnover versus binding assays

Conservation of the unusual dimeric JmjC fold of JMJD7 from Drosophila melanogaster to humans

The JmjC family of 2-oxoglutarate dependent oxygenases catalyse a range of hydroxylation and demethylation reactions in humans and other animals. Jumonji domain-containing 7 (JMJD7) is a JmjC (3S)-lysyl-hydroxylase that catalyses the modification of Developmentally Regulated GTP Binding Proteins 1 and 2 (DRG1 and 2); JMJD7 has also been reported to have histone endopeptidase activity. Here we report biophysical and biochemical studies on JMJD7 from Drosophila melanogaster (dmJMJD7). Notably, crystallographic analyses reveal that the unusual dimerization mode of JMJD7, which involves interactions between both the N- and C-terminal regions of both dmJMJD7 monomers and disulfide formation, is conserved in human JMJD7 (hsJMJD7). The results further support the assignment of JMJD7 as a lysyl hydroxylase and will help enable the development of selective inhibitors for it and other JmjC oxygenases

Museum collections: Natural history training bridges time, space, and digital platforms.

Natural history collections offer a number of unique physical and virtual opportunities to create formal and informal progressive learning environments. Collections provide direct interaction with biodiversity as it changes through time and space. Collections-based experiences lead to an increased understanding and substantive interaction with the living world. Recent studies demonstrate how nature and outdoor experiences can improve learning. We discuss how collections, and the data associated with collections, are a critical component linking nature and scientific inquiry. Partnerships that develop around collections and collections-based science can foster innovative educational and research experiences that are enhanced by access to museum specimens. Such collaborations can also facilitate new avenues of learning through not only traditional classroom settings, but also citizen science initiatives, cross-disciplinary field experiences, or other place-based learning environments. We emphasize how the recent surge in specimen-based digitization initiatives has resulted in unprecedented access to a wealth of biodiversity information and how this vastly expands the reach of natural history collections. Natural history collections, the data they contain, and the emergences of digital databases enable scientists and the public to address global, regional, and local issues related to biodiversity that were simply unachievable a decade ago