A. Bruce Cahoon

A. Bruce CahoonBruce Cahoon

Buchanan Endowed Chair of Biology

E-mail: abc6c@uvawise.edu
Phone: 276.328.0201
Office: Science 137


  • Doctor of Philosophy (Biology), University of Virginia, Charlottesville, VA, 2001
  • Master of Science (Biology), Virginia Commonwealth University, Richmond VA, 1994
  • Bachelor of Science (Biology) Virginia Commonwealth University, Richmond, VA, 1991

Courses Taught

  • Principles of Biology
  • Genes and GMOs
  • Principles of Biology Laboratory
  • Introduction to Biological Diversity
  • Plant Cell Function
  • Local Flora

Research Interests

My research focuses on two broad areas – protist biodiversity and plant cell organelle gene expression.

1. Protist Biodiversity and Biogeography in Appalachian Freshwater Systems: There are numerous natural and man-made freshwater ponds and waterways in the southern Appalachian region yet there is very little exploration of the microscopic eukaryotic organisms within these systems. Since 2015, members of my lab have been collecting water samples from streams, reservoirs, and man-made ponds of various ages in southwest Virginia and using a metagenomic barcoding strategy to identify microalgae and protozoans. As of the spring 2017 we have completed nearly 100 samples to 1 – create a database of protists living in the region, 2 – study temporal changes in protist populations, and 3 – correlate protist blooms or species to abiotic factors.

2. Organelle Gene Expression: Chloroplasts and mitochondria are semi-autonomous organelles that were incorporated into pre-eukaryotic cells through a process called endosymbiosis. They have circular chromosomes with genes that are organized and expressed in ways that are unique in the biological world. This includes multiple post-transcriptional processing steps, including trans-splicing, RNA editing, odd poly-cistronic gene groups, transcript separation, poly-A degradation signaling, and others.  Land plant and algal organelles share some post-transcriptional modification mechanisms but  also differ significantly ­ for example, algae do not edit mRNAs but land plants do and some algae add polynucleotide stretches to 3¹ ends whereas land plants do not.  Since green algae and land plants share a common evolutionary history it is interesting to tease apart the differences between these two groups of organisms.  Most recently my lab has been using deep transcriptome sequencing to explore transcript processing of several green algae and two dinoflagellates, Karenia brevis and Pyrocystis lunula.

Selected Publications

Roseanna M. Crowell, James A. Nienow, and Aubrey Bruce Cahoon (2019)  The complete chloroplast and mitochondrial genomes of the diatom Nitzschia palea (Bacillariophyceae) demonstrate high sequence similarity to the endosymbiont organelles of the dinotom Durinskia baltica.  Journal of Phycology

A. Bruce Cahoon, Ashley G. Huffman, Megan M. Krager, Roseanna M. Crowell (2018) A meta-barcoding census of freshwater planktonic protists in Appalachia – Natural Tunnel State Park, Virginia, USA. Metabarcoding and Metagenomics 2:e26939

A. Bruce Cahoon and Ali A. Qureshi (2018) Leaderless mRNAs are Circularized in Chlamydomonas reinhardtii Mitochondria. Current Genetics.

Christen M. Klinger, Lucas Paoli, Robert Newby, Matthew Yu-Wei Wang, Hyrum D. Carroll, Jeffrey D. Leblond, Christopher J. Howe, Joel B. Dacks, Bruce Cahoon, Richard G. Dorrell, and Elisabeth Richardson  (2018) Plastid transcript editing across dinoflagellate lineages shows lineage-specific application but conserved trends.  Genome Biology and Evolution. 10:1019-1038

Cahoon, A. B., Nauss, J.N., Stanley, C.D., Qureshi, A. (2017) Deep Transcriptome Sequencing of Two Green Algae, Chara vulgaris and Chlamydomonas reinhardtii, Provides no Evidence of Organellar RNA Editing.  Genes 8(2)

Lee, S. A., Wrona, L. J., Cahoon, A. B., Crigler, J., Eiteman, M. A., Altman, E.  (2016).  Isolation and comparison of bacteria that use furans as the sole carbon source. Applied Biochemistry and Biotechnology 178:76-90

Bhawana, Jeannie Stubblefield, Anthony Newsome, A. Bruce Cahoon (2015) Surface decontamination of plant tissue explants with chlorine dioxide gas. In Vitro Cellular and Developmental Biology – Plant 51:214-219

Bhawana, Joyce L. Miller, and A. Bruce Cahoon (2014) Visualization of 3-Dimensional Plant Cell Architecture in Different Tissues of Arabidopsis thaliana with Focused Ion Beam-Scanning Electron Microscopy.  Applications in Plant Science 2:6

Benjamin T. Grimes, Awa K. Sisay, Hyrum D. Carroll, A. Bruce Cahoon (2014) Deep Sequencing of the Tobacco Mitochondrial Transcriptome Reveals Expressed ORFs and Numerous Editing Sites Outside Coding Regions.  BMC Genomics 15:31

Jacob B. Hall, Vincent A. Cobb, A.Bruce Cahoon. (2013) The complete mitochondrial DNA sequence of Crotalus horridus (timber rattlesnake).  Mitochondrial DNA.  24:94-96

Sheri Mersch and A. Bruce Cahoon (2012) Ky31 tall fescue can outcompete MaxQ through more efficient utilization of a hydrophilic compound produced by the endophyte Neotyphodium coenophialum. Grass and Forage Science.  67:299-304

Abby M. Drumwright, Brian W. Allen, Krista A. Huff, Patricia A. Ritchey, A. Bruce Cahoon.  (2011).  Survey and DNA Barcoding of Poaecea in Flat Rock Cedar Glades and Barrens State Natural Area, Murfreesboro, TN.  Castanea 76:300-310

R.M. Sharpe, A. Mahajan, E. Takacs, D. B. Stern, A. B. Cahoon (2011) Developmental and cell type characterization of bundle sheath and mesophyll chloroplast-encoded transcript abundance in maize.  Current Genetics 57:89-102

Bruce Cahoon, R. M. Sharpe, C. Mysayphonh, E. J. Thompson, A. D. Ward, Anhua Lin (2010) The Complete Chloroplast Genome of Tall Fescue (Lolium arundinaceum, “Poaceae”) and the Comparison of Whole Plastomes from the Family Poaceae. American Journal of Botany 97: 49-58

Sharpe RM, Dunn SN, Cahoon AB (2008) A Plastome Primer Set for Comprehensive Quantitative Real Time RT-PCR Analysis of Zea mays: A Starter Primer Set for Other Poaceae Species.  Plant Methods 4:14

B. Cahoon, E. M. Takacs, R.M. Sharpe*, D. B. Stern. (2008) Nuclear, Chloroplast, and Mitochondrial Transcript Abundance Along a Maize Leaf Developmental Gradient. Plant Molecular Biology 66:33-46

B. Cahoon, Y. Komine, D.B. Stern. (2006) Plastid Transcription: Competition, Regulation and Promotion by Plastid- and Nuclear Encoded Polymerases.  In The Structure and Function of Plastids.  R. R. Wise, J. K, Hoober (Eds.) Advances in Photosynthesis and Respiration.  Volume 23: pp 167-181

B. Cahoon, F.M. Harris & D. B. Stern. (2004) Analysis of developing maize plastids reveals two mRNA stability classes correlating with RNA polymerase type. EMBO Reports  5:801-806

A.B. Cahoon, K.A. Cunningham, T.J. Bollenbach, D.B. Stern. (2003)   Maize BMS cultured cell lines survive with massive plastid gene loss. Current Genetics 44:104-113

A.B. Cahoon, K.A. Cunningham, D.B. Stern. (2003)  The plastid clpP gene may not be essential for plant cell viability.  Plant and Cell Physiology 44: 93-95

A.B. Cahoon and M.P. Timko (2003) Biochemistry and Regulation of Chlorophyll Biosynthesis. , In Photosynthesis in Algae.  A.W. Larkum, S. Douglas, J.A. Raven (Eds.)  Kluwer Academic Publishers, Netherlands.

A.B. Cahoon and D.B. Stern (2001) Plastid transcription: a menage á trois? Trends in Plant Science. 6:45-46.

A.B. Cahoon and M.P. Timko (2000) The phenotype of “yellow-in-the-dark” mutants of Chlamydomonas Results from the Loss of Expression of CHLL.  Plant Cell  12:559-568.

 Recent Presentations

Anna M. Crowell, James A. Nienow, A. Bruce Cahoon. (2018) The Complete Chloroplast and Mitochondrial Genome Sequences for an Appalachian Isolate of the Freshwater Diatom, Nitzschia palea.  Northeastern Algal Society Meeting. New Haven, CT.

A. Bruce Cahoon, Ashley G. Huffman, Megan M. Krager, Roseanna M. Crowell. (2018)  A Short-Term Temporal Meta-Barcoding Survey of Planktonic Protists in Appalachia –  Natural Tunnel State Park, Virginia, USA.  Northeastern Algal Society Meeting. New Haven, CT.

A. Bruce Cahoon and Ali Qureshi. (2018) Circularization of Chlamydomonas reinhardtii mitochondrial mRNAs place ribosome biding sites upstream of leaderless transcripts.  Association of Southeastern Biologists Meeting.  Myrtle Beach, SC.

A. Bruce Cahoon, Ashley G. Huffman, Megan M. Krager, Roseanna M. Crowell. (2018)  A Short-Term Temporal Meta-Barcoding Survey of Planktonic Protists in Appalachia –  Natural Tunnel State Park, Virginia, USA.  Association of Southeastern Biologists Meeting.  Myrtle Beach, SC.

Rachel E. McGlone, A. Bruce Cahoon, Walter H. Smith (2018).  The development of a DNA barcode assay to detect the green salamander (Aneides aeneus) from eDNA sampling.  Association of Southeastern Biologists Meeting.  Myrtle Beach, SC.

Brandon Thompson, Robert VanGundy, and A. Bruce Cahoon. (2018) Metabarcoding Analysis of Cave Prokaryotic Microbiomes in Southwest VA.  Association of Southeastern Biologists Meeting.  Myrtle Beach, SC.

A. Bruce Cahoon, Ashley G. Huffman, Megan M. Krager, Roseanna M. Crowell.  (2017) A Short Term Temporal Meta-Barcoding Survey of Planktonic Protists in the Cumberland Mountains –  Natural Tunnel State Park, Virginia, USA.  University of Virginia’s College at Wise, Department of Natural Sciences, Wise, VA. USA. 39th Annual Southeastern Phycological Colloquy,  UNC-Wilmington

Bruce Cahoon (presenter), Jason Woods, Ashley Huffman, Anna Crowell.  (2017)  Biodiversity of freshwater microalgae in southern Appalachian coalfield region determined by metagenomic barcoding, Phycological Society of America, Monterey, CA

A. Bruce Cahoon, Anna Crowell, Ashley Huffman*, Jason Woods (2016)  Microalgal diversity in southern Appalachian waterways.  38th Annual Southeastern Phycological Colloquy,  Valdosta State University.

Jason Woods and A. Bruce Cahoon (2016)  A Metagenomic Survey of Planktonic Algae in Southern Appalachian Ponds.  National Council for Undergraduate Research (NCUR) annual meeting, UNC-Asheville.