Brian Morton

 Professor of Biology

Brian R. Morton, Professor of Biological Sciences, joined the Barnard faculty in 1995.

One area of Professor Morton's research focuses on two main aspects of genome evolution, with an emphasis on plant plastid genomes.

The first is the selective constraints on both codon usage and genome structure across a wide variety of phyla of the plant kingdom. He is attempting to determine how and why selection intensity varies among lineages as well as over time. He is also interested in finding out how selective constraints on codon usage interact with other structural features, such as amino acid composition of proteins and genome organization.

His second major line of research involves an investigation of the nucleotide substitution dynamics of plastid DNA. Professor Morton and his research team are studying the ways in which rate heterogeneity among sites is affected by variation in context, or the composition of nucleotides flanking those sites.

Another area of research examines the chemosensory receptor superfamily in the tobacco hornworm (Manduca sexta). We have identified several dozen putative olfactory and gustatory receptor genes in the newly sequenced genome and inferred function based on sequence similarity to other insect chemosensory proteins. We are now utilizing the CRISPR-Cas9 genome editing tool to generate knock-out mutants for these genes in order to better characterize their function.

Selected Publications

Suzuki H, Morton BR (2016) Codon Adaptation of Plastid Genes. PLoS ONE 11(5): e0154306.

Kanost MR, Morton B, Shukla A, Hirsh A and 110 others (2016) Multifaceted biological insights from a draft genome sequence of the tobacco hornworm moth, Manduca sexta. Insect Biochem Mol Biol. 2016 Sep;76:118-47. doi: 10.1016/j.ibmb.2016.07.005.

Koenig C, Hirsh A, Bucks S, Klinner C, Vogel H, Shukla A, Mansfield JH, Morton B, Hansson BS, Grosse-Wilde E. 2015. A reference gene set for chemosensory receptor genes of Manduca sexta. Insect Biochemistry and Molecular Biology 66: 51-63.

Afroz A, Howlett N, Shukla A, Ahmad F, Batista E, Bedard K, Payne S, Morton B, Mansfield J. H., and J. I. Glendinning 2013. A TrpA1-dependent pathway integrates taste and temperature in Manduca sexta. Chemical Senses 38(7): 605-617.

Howlett N, Dauber K, Shukla A, Morton B, Glendinning JI, Brent E, Gleason C, Islam F, Izquierdo D, Sanghavi S, Afroz A, Aslam A, Barbaro M, Blutstein R, Borkova M, Desire B, Elikis A, Fan Q, Hoffman K, Huang A, Keefe D, Lopatin S, Miller S, Patel P, Rizzini D, Robinson A, Rokins K, Turlik A, and J. H. Mansfield 2012. Identification of chemosensory receptor genes in Manduca sexta and knockdown by RNA interference. BMC Genomics 13:211.

Morton B. R., Dar V. and S. I. Wright 2008. Analysis of site frequency spectra from Arabidopsis with context-dependent corrections for ancestral misinference. Plant Phys. 149:616-624.

Morton R. A. and B. R. Morton 2007. A maximum likelihood analysis of compositional skew in microbial genomes. BMC Genomics 8:369.

Zheng T., Ichiba T. and B. R. Morton 2007. Assessing substitution variation across sites in grass chloroplast DNA. J. Mol. Evol. 64:605-613.

Morton B. R. and S. I. Wright 2007. Selective constraints on codon usage of nuclear genes from Arabidopsis thaliana. Mol. Biol. Evol. 24:122-129.

Tillich M., Lewahrk P., Morton B. R. and U. G. Maier 2006. The evolution of chloroplast RNA editing. Mol. Biol. Evol. 23:1912-1921.

Morton B. R., Bi I. V., McMullen M. D. and B. S. Gaut 2006. Variation in mutation dynamics across the maize genome as a function of regional and flanking base composition. Genetics (172:569-577)

Morton B. R. 2003. The role of context-dependent mutations in generating compositional and codon usage bias in grass chloroplast DNA. J. Mol. Evol. 56:616-629.

Academic Focus: 

Molecular evolution

Evolutionary genomics


Molecular & Mendelian Genetics (BIOL BC2100)

Evolution (BIOL BC 2272)

Genomics and Bioinformatics (BIOL BC3308)

Science and Public Policy (SCPP BC3333)

Lab in Genetics (BIOL BC2801)

Project Lab in Molecular Genetics (BIOL BC3305/6)


BS, University of Toronto
PhD, University of California, Riverside

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