Click on this link to download the full high-definition interactive pdf for AJUR Volume 7 Issue 1 (June 2020)
Links to individual manuscripts, abstracts, and keywords are provided below.
p.3. 9-Borobicyclo[3.3.1]nonane-Catalyzed Hydroboration of Terminal Aromatic Alkynes with Pinacolborane
Garett L. Ruesch, Sydney L. Rowley, Marcus C. Mifflin, & Nathan S. Werner*
Department of Physical Science, Southern Utah University, Cedar City, UT
ABSTRACT: Organoboron compounds are extensively used in organic synthesis. The alkenylboronic acid pinacol esters formed from the hydroboration reaction of alkynes with pinacolborane are stable, easy to handle, and useful in many synthetic transformations. However, pinacolborane lacks the reactivity necessary to undergo facile hydroboration reaction with terminal aromatic alkynes. 9-Borobicyclo[3.3.1]nonane (9-BBN) can be used to catalyze the hydroboration reaction of phenylacetylene with pinacolborane. The hydroboration reaction parameters and product purification conditions were evaluated to maximize the yield of (E)-2-phenylethenylboronic acid pinacol ester. It was found that the optimal reaction conditions for the 9-BBN-catalyzed hydroboration of phenylacetylene with pinacolborane were: phenylacetylene (1.0 equiv), pinacolborane (1.2 equiv), 9-BBN (20 mol%), and THF [0.2] at 65 °C. The compatibility of these reaction conditions with p-substituted terminal aromatic alkynes bearing electronically diverse groups was studied. Moderate to good yield (49–76%) of the hydroboration products were isolated after purification by liquid-liquid extraction and flash chromatography.
KEYWORDS: Organic Synthesis; Catalysis; Methods Development; Hydroboration; Reaction Optimization; Alkenylboronic Ester; Alkyne; Pinacolborane; 9-Borobicyclo[3.3.1]nonane
p.13. Synthetic Biology Bicistronic Designs Support Gene Expression Equally Well in vitro and in vivo
Owen Kouckya, Jacob Wagnerb, Sofia Aguilerab, Benjamin Bashawb, Queena Chena, Anthony Eckdahla, Elise Edmanc, Paul Gomeza, Nick Hanlanb, Nick Kempfd, Devin Mattoond, Sam McKlina, Christopher Mazariegosa, Alex Moreheadd, Shi Qing Ongb, Andy Petersonc, Maria Rojasa, Kyla Rolanda,, Kaitlyn Schildknechtc, Haley Seligmannc, Kaden Slaterd, Ali Tauchenb, Raechel Tittorb, Tatianna Traviesoa, Dannie Urband, Caroline Willisa, John Zhoua, Nicole L. Snydere, Laurie J. Heyerc, Jeffrey L. Poetd, Todd T. Eckdahlb, & A. Malcolm Campbell*a
aDepartment of Biology, Davidson College, Davidson, NC
bDepartment of Biology, Missouri Western State University, St. Joseph, MO
cDepartment of Mathematics and Computer Science, Davidson College, Davidson, NC
dDepartment of Computer Science, Math, and Physics, Missouri Western State University, St. Joseph, MO
eDepartment of Chemistry, Davidson College, Davidson, NC
ABSTRACT: Synthetic biology integrates molecular biology tools and an engineering mindset to address challenges in medicine, agriculture, bioremediation, and biomanufacturing. A persistent problem in synthetic biology has been designing genetic circuits that produce predictable levels of protein. In 2013, Mutalik and colleagues developed bicistronic designs (BCDs) that make protein production more predicable in bacterial cells (in vivo). With the growing interest in producing proteins outside of cells (in vitro), we wanted to know if BCDs would work as predictably in cell-free protein synthesis (CFPS) as they do in E. coli cells. We tested 20 BCDs in CFPS and found they performed very similarly in vitro and in vivo. As a step toward developing methods for protein production in artificial cells, we also tested 3 BCDs inside nanoliter-scaled microfluidic droplets. The BCDs worked well in the microfluidic droplets, but their relative protein production levels were not as predictable as expected. These results suggest that the conditions under which gene expression happens in droplets result in a different relationship between genetic control elements such as BCDs and protein production than exists in batch CFPS or in cells.
KEYWORDS: Bicistronic Design; Synthetic Biology; Cell-Free Protein Synthesis; Microfluidics
p.21. Survey of Wolbachia frequency in Nashville, Tennessee Reveals Novel Infections
Sangami Pugazenthi, Phoebe White, Aakash Basu, Anoop Chandrashekar, & J. Dylan Shropshire*
Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
ABSTRACT: Wolbachia (Rickettsiales: Anaplasmataceae) are maternally transmitted intracellular bacteria that infect approximately half of all insect species. These bacteria commonly act as reproductive parasites or mutualists to enhance their transmission from mother to offspring, resulting in high prevalence among some species. Despite decades of research on Wolbachia’s global frequency, there are many arthropod families and geographic regions that have not been tested for Wolbachia. Here, arthropods were collected on the Vanderbilt University campus in Nashville, Tennessee, where Wolbachia frequency has not been previously studied. The dataset consists of 220 samples spanning 34 unique arthropod families collected on the Vanderbilt University campus. The majority of our samples were from the families Blattidae (Blattodea), Pulicidae (Siphonaptera), Dryinidae (Hymenoptera), Aphididae (Hemiptera), Paronellidae (Entomobryomorpha), Formicidae (Hymenoptera), Pseudococcidae (Hemiptera), Sphaeroceridae (Diptera), and Coccinellidae (Coleoptera). PCR-based techniques were used to assign infection states and, from these data, the first cases of Wolbachia in the Paronellidae springtails, Lithobiidae (Lithobiomorpha) centipedes, Lonchopteridae (Diptera) spear-winged flies, Sepsidae (Diptera) black scavenger flies, Cryptocercidae (Blattodea) wood roaches, and Lauxaniidae (Diptera) acalyptrate flies were identified. Within-family infection frequencies ranged from 17-100% when Wolbachia was observed; however, numerous families tested did not reveal evidence of infection. These results expand on the field’s understanding of Wolbachia’sfrequencyin Nashville, Tennessee, and among arthropod families broadly, and is the first report of Wolbachia in centipedes.
KEYWORDS: Wolbachia; Infection Frequency; Endosymbiont; Tennessee; Centipede; Arthropod; Polymerase Chain Reaction; Nashville