Edinburgh Research Explorer

Dr Catherine Kidner

Senior Lecturer

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Willingness to take Ph.D. students: Yes

Does a dynamic genome drive speciation in a mega diverse genus? Begonia is one of the most specious plant genera with likely 2,000 species found throughout the tropics. The only other genus in the family Begoniaceae, Hildebrandia, comprises only a single species. We wish to understand what has driven this high level of speciation. We know from previous work that Begonia generally exist in small, isolated populations, however, by its self this would not be enough to generate reproductive isolation and speciation. A notable feature of Begonia is the variation in genome size and chromosome number across the genus. It ranges from c values of 0.23pg to 1.46pg and chromosome numbers of 2n = 22 to 2n = 156. A dynamic genome with active repeat elements may underlie high speciation rates (Leitch AR, and Leitch IJ., 2012). A draft Begonia genome we have produced confirms the presence of high numbers of repetitive elements, including active transposons in Begonia which could be driving this variation. Genome skims from 12 species have been analysed with Repeat Explorer (Novak et al., 2013) and show a high level of diversity between species in the numbers and types of repetitive elements present. There have also been B chromosomes documented in the group (deWitte et al., 2009). B chromosomes are correlated with large genome sizes and with highly speciose groups (Jones et al., 2003) This project will test the hypothesis that a dynamic genome driven by bursts of transposon activity could be creating sufficient variation between isolated populations to generate reproductive isolation, driving speciation. The draft genome sequence will be analysed in detail to fully characterise the transposons and date their activity. Genome skims of a phylogenetically balanced survey of Begonia species and of Hildebrandia sanwichensis will be added to the 12 we already have to provide a full overview of repetative elements in the family. c values and chromosome counts will be produced for all the species sequenced (Pellicer J and Leitch IJ.,2014) . This dataset will allow us to test the hypothesis that high rates of speciation are correlated with high transposon activity, variation in genome size and presence of B chromosomes. We have transcriptomes of five tissue types for two species of Begonia. Bioformatic analysis will be used to determine whether transposons are active in the reproductive tissue and how this activity varies between the species. This data will be confirmed by Q-RT-PCR and southern blotting. We will also test the hypothesis on an intraspecific scale using populations of B. heracleifolia collected across Mexico which vary in genome size (Twyford et al., 2015). Genome skims will be used to determine the make up of the extra DNA and crossing experiments used to establish the effect of this variation on reproductive isolation.

Qualifications

Postdoctoral Researcher CSHL, NY 1997 - 2004

PhD University of East Anglia 1997

BA Oxford University 1994

Current Research Interests

We are interested in determining the genetics underlying differences between species.  We would like to know how many genetic changes and what type of changes cause variation in plant growth and form.  A combination of classical genetics and new sequencing technologies is being used to link the variation in form to variation in the sequence and expression of genes. We are particularly interested applying these techniques to tropical species, as the tropics contain most of the world’s diversity but have been genetically understudied.

As a study system we are working on Begonia, a species rich genus (1500+ species) found in wet rainforests throughout the world, with a focus on Section Gireoudia.  This is a group of about 66 Central American Begonia species, very variable in form and including many examples of convergent evolution, which makes it an excellent system to study the evolution of development.

Research students

Katie Emilieova Started Sept 20012.
    Gene duplication in Begonia. Funded by BBSRC
Mansour Abdullah Started Feb 2012
    Barcoding the flora of Kuwait.  (Second supervisor)

Past Students
Saima Umbreen Started Jan 2007.  Graduated Sept 2011
    ARP genes in Begonia leaf evolution Funded by HEC , Pakistan
Nicola Burton Started Sept 2007 (viva Nov 2012)
    The evolution of Begonia section Gireoudia. Funded by BBSRC
Mobina Shaukat.  Started April 2007 (viva Nov 2012)
    The genetic architecture of species level variation in Begonia Funded by HEC , Pakistan
Alex Twyford Started Sept 2008, (Graduated Oct 2012)
    Hybrid vigour in Begonia. Funded by BBSRC
Steven Wrigely Started Sept 2010, left Jan 2012
    Rare species and rare niches. Funded by BBSRC
Muhammad Hyat Qasim 2010 A phylogeny of Artemisia (Second supervisor, Quaid-i-Azam University, Islamabad)

Collaborative Activity

Chemistry, taxonomy and diversification in tropical plants: a case study of Inga.

Collaboration with Toby Pennington (RBGE), Graham Stone (UoE), Tom Kusar and Phyllis Kusar (Univerity of Utah).

 

Ecophysiology and anatomy in Begonia

Collaboration wth Gail Jackson, School of Geosciences, UoE

 

Population genetics of Begonia hybrid zones

Collaboration with Richard Ennos, Institute of Evolutionary Biology, UoE

 

Phylogeography of Mexican Begonia

Collaboration with James Richardson, RBGE

 

Developmental diversity of Streptocarpus

Collaboration with Michael Moller, RBGE and Kanae Nishi, National Taiwan University

 

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