Nicola Illing | Evolution of Development

My primary research interest is to use the tools of modern genetics to unravel the answers to interesting evolutionary and developmental biology questions, using examples from the rich biological landscape of southern Africa.   Genetic analysis of organisms that are currently alive can be used to delve into the past, for example, understanding how flight evolved in the Natal long finger bat, Miniopterus natalensis  50 million years ago.  Similarly, we are using genetics and cell biology to understand how vegetative desiccation tolerance evolved in Xerophyta resurrection plants, and how floral symmetry is broken in the mirror image flowers of Wachendorfia paniculata and Cyanella alba. 

Masters OR PhD studentship Research Position: Closing date June 30, 2021
Postdoctoral Research Position: Closing date June 30, 2021

1. Kappel, C, Illing, N, Nguyen Huu, C, Barger, NN, Cramer, MD, Lenhard, M, and Midgley, JJ (2020) Fairy circles in Namibia are assembled from genetically distinct grasses. Commun Biol 3:698. doi: 10.1038/s42003-020-01431-0.
2. Lyall R, Schlebusch SA, Proctor J, Prag M, Hussey SG, Ingle RA, Illing N. (2020).  Vegetative desiccation tolerance in the resurrection plant Xerophyta humilis has not evolved through reactivation of the seed canonical LAFL regulatory network.  Plant J. 101:1349-1367. doi: 10.1111/tpj.14596. PMID: 31680354
3. Yuan C, Meng X, Li X, Illing N, Ingle RA, Wang J, Chen M. (2017). PceRBase: a database of plant competing endogenous RNA.Nucleic Acids Res. 2017 Jan 4; 45(D1):D1009-D1014. doi: 10.1093/nar/gkw916
4. Eckalbar WL , Schlebusch SA,  Mason MK, Gill Z, Parker AV,  Booker  BM,  Nishizaki S,  Muswamba-Nday C, Terhune  E, Nevonen  K,  Makki N,   Friedrich T, VanderMeer JE, Pollard KS, Carbone L, Wall JD, Illing N, Ahituv N. (2016) Epigenomic and transcriptomic characterization of the developing bat wing. Nature Genetics. doi:10.1038/ng.3537
5. Breen MS, Uhlmann A, Nday CM, Glatt SJ, Mitt M, Metsalpu A, Stein DJ, Illing N (2016) Candidate gene networks and blood biomarkers of methamphetamine-associated psychosis: an integrative RNA-sequencing report. Translational Psychiatry. 6:e802. doi: 10.1038/tp.2016.67
6. Booker B, Friedrich T, Mason MK, VanderMeer JE, Zhao J, Eckalbar WL, Logan M, Illing N, Pollard KS, Ahituv N. (2016) Bat accelerated regions identify a bat forelimb specific enhancer in the HoxD locus, PLoS Genetics. http://dx.doi.org/10.1371/journal.pgen.1005738
7. Mason, M.K., Hockman, D., Curry, L., Cunningham, T.J., Duester, G., Logan, M., Jacobs, D.S., and Illing, N. (2015). Retinoic acid-independent expression of Meis2 during autopod patterning in the developing bat and mouse limb. EvoDevo 10.1186/s13227-015-0001-y
8. Lyall, R; Ingle, R. A. and Illing, N. (2014). The Window of Desiccation Tolerance Shown by Early-Stage Germinating Seedlings Remains Open in the Resurrection Plant, Xerophyta viscosa. PLoS ONE 9:3: e93093
9. Tonnabel J, Mignot A, Douzery EJ, Rebelo AG, Schurr FM, Midgley J, Illing N, Justy F, Orcel D, and Olivieri I (2014) Convergent and correlated evolution of major life-history traits in the angiosperm genus Leucadendron (proteaceae). Evolution.68(10):2775-92. doi: 10.1111/evo.12480.
10. Ravasi DF, O’Riain MJ, Davids F, Illing N (2012) Phylogenetic Evidence That Two Distinct Trichuris Genotypes Infect both Humans and Non-Human Primates. PLoS ONE 7(8): e44187.

Mamosa Ngcala
Eugene Kabwe
Michael Edwards
Christine Osborn
Ruchi Rani

Evolution of vegetative desiccation tolerance in Xerophyta resurrection plants

European Commission Funded project: RESIST

Collaborators: Assoc. Prof. Robert Ingle (UCT), Prof. Zoran Nikoloski (University of Potsdam), Dr Rafe Lyall (Centre for Plant Systems Biology and Biotechnology, Plovdiv, Bulgaria), Prof. Yariv Brotman (Ben-Gurion University of the Nedev, Israel)

Xerophyta species, including Xerophyta elegans, Xerophyta humilis, and Xerophyta schlechteri can survive desiccation at all stages of plant development.  Most Xerophyta species dismantle the thylakoid membranes in their chloroplasts, and break their chlorophyll down (i.e are poikilochlorophyllous) as leaves desiccate. However X. elegans does not (ie is homoiochlorophyllous), preferring to grow in the shade.  We are using a comparative genome analysis between these three Xerophyta species to unlock the conserved genetic signatures that allow drying without dying.  

An analysis of miRNA-seq, RNA-seq, metabolite and lipid datasets generated from a detailed sampling of X. elegans seedlings undergoing desiccation and subsequent rehydration will be used to decipher the gene regulatory networks underpinning protection against desiccation, and the subsequent recovery, without major changes in the structure of chloroplasts.
What is the relevance of this research? Although crops in the earliest stages of germination can survive desiccation, this valuable trait is lost as seedlings mature  We are extending our studies to investigate gene regulatory pathways activated as germinating barley seedlings desiccate. These finding will inform us whether the drought tolerance of barley grown under dryland crop conditions can be improved.

The biology of left-right asymmetry - linking structural determinants to ecology and evolution

Human Frontiers Research Programme (HFSP) Funded project:

Collaborative project including Prof. Michael Lenhard, University of Potsdam, Prof. Spencer Barratt (University of Toronto), Dr Eva Denium (University of Wagenenin), Prof. Bruce Anderson (University of Stellenbosch), Assoc. Prof. Robert Ingle and Prof. Dirk Lang (University of Cape Town).

The body plans of most plants and animals are symmetrical. Understanding how symmetry is broken is an important question in biology. For example, in flowers, the female and male reproductive organs (ie the pistil and stamen) are usually symmetrically placed relative to each other.  In rare cases, this symmetry is broken. These plants have mirror-image flowers, and are referred to as being enantiostylous. We are studying this problem in Wachendorfia paniculata and Cyanella alba, where the style (part of the pistil) is directed either to the left or right of the midline, while the anthers point in the other direction.  Half the population of these plants are either left- or right-handed, and thus we know that this patterning must be determined by simple genetic control.  Our research seeks to

• identify these genes
• understand how these genes pattern the reproductive organs of mirror image flowers
• quantify the ecological impact of mirror-image flowers in terms of pollination success
• trace how mirror-image flowers evolved. 

Further listening and reading

Podcast by Prof. Bruce Anderson
Darwin’s last wish – studying handedness in plants, popular article by Prof. Bruce Anderson
Barrett, SCH (2002) The evolution of plant sexual diversity. Nature Reviews Genetics
Jesson LK and Barrett SCH (2003) The comparative biology of mirror-image flowers. International Journal of Plant Sciences