Jen photographing Andeimalva machupicchensis at Machu Picchu, Peru

Evolution of polyploidy in plants

Much of my research has focused on the evolution of plant polyploids, from identifying the progenitors of polyploid species using phylogenetic methods, to examining the fate of genes duplicated by polyploidy using molecular genetic techniques. Polyploidy can have significant consequences on the entire organism, from genomic incompatibilities to changes in ecological tolerances. As a result, studies of polyploidy naturally allow for an integrative approach to research. The main goals of my research are to identify progenitor species of natural polyploids, so that the genetic, genomic, and phenotypic consequences of polyploidy in natural systems can be understood.

Currently, I am a postdoctoral research associate in the Soltis lab at the University of Florida. We are investigating genome evolution in the New World allopolyploid Tragopogon species, T. miscellus and T. mirus. These two allopolyploids formed within the past 80 years following the introduction of three diploids (T. dubius, T. pratensis, and T. porrifolius) from Europe to western North America. Because the parentage and time of formation of these polyploids are well documented, this system provides a unique opportunity to study the consequences of recent and recurrent polyploidization. As part of our collaborative NSF grant with Dr. Jeff Chen (University of Texas at Austin), we are using a variety of molecular genetic approaches (cDNA-AFLP, RT-PCR, CAPS, SNPs) to investigate the evolution and expression of homoeologous loci (genes duplicated by polyploidy) in Tragopogon.

Publications:

Tate, J. A. and B. B. Simpson. 2003. Paraphyly of Tarasa Philippi (Malvaceae) and diverse origins of the polyploid species. Systematic Botany 28: 723-737. PDF

Tate, J. A. and B. B. Simpson. 2004. Breeding system evolution in Tarasa (Malvaceae) and selection for reduced pollen grain size in the polyploid species. American Journal of Botany 91: 207-213. PDF

Soltis, D. E., P. S. Soltis, J. C. Pires, A. Kovarik, J. A. Tate, and E. Mavrodiev. 2004. Recent and recurrent polyploidy in Tragopogon (Asteraceae): Genetic, genomic, and cytogenetic comparisons. Biological Journal of the Linnean Society 82: 485-501. PDF

Tarasa antofagastana (left), a tetraploid annual, with one of its putative progenitors, T. meyeri (right), a diploid annual

Phylogenetic systematics of tribe Malveae (Malvaceae)

Tribe Malveae is the largest in subfamily Malvoideae with approximately 75 genera and over 1000 species. Currently, I am collaborating with Dr. Randy Small (University of Tennessee) to reconstruct phylogenetic relationships in tribe Malveae using chloroplast DNA sequence data from several regions (rpl16 and matK-3’trnK introns, ndhF), along with sequences from a low copy nuclear gene (granule bound starch synthase or “waxy”). Using these additional datasets, we are evaluating generic boundaries, biogeography, and character evolution within the tribe. Given the complex chromosomal evolution in many lineages of the tribe, we are particularly interested in examining the role that polyploidy has played in terms of rates of molecular evolution, biogeographic radiations, and character evolution.

Publications:

Tate, J. A., J. Fuertes Aguilar, S. J. Wagstaff, J. C. La Duke, T. A. Bodo Slotta, and B. B. Simpson. 2005. Phylogenetic relationships within the tribe Malveae (subfamily Malvoideae, Malvaceae) as inferred from ITS sequence data. American Journal of Botany 92: 584-602. PDF

Tate, J. A. 2003. Andeimalva: a new genus of Malvaceae from Andean South America. Lundellia 6: 10-18. PDF

C.V.

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