Developmental Molecular Genetics
Dr Karim Sorefan - Lecturer (commences in the Department in May 2013)
Career History
May 2013: Lecturer, Dept. of Molecular biology and Biotechnology, Sheffield, UK
2009-2013: Senior Postdoctoral Researcher, University of East Anglia, Norwich, UK
2002-2009: Postdoctoral Researcher, John Innes Centre, Norwich, UK
1998-2002: PhD Student, University of York, UK
1996-1998: Research Technician, University of Leicester, UK
My Laboratory works on the molecular mechanisms regulating plant development with a particular focus on linking miRNA and hormonal pathways.
Plant Stem Cell Niche Development
All above ground tissues arise from a small mound of stem cells. These meristematic cells are programmed through hormonal and small RNA mechanisms to develop leaves and flowers (Fig 1). ARGONAUTE10 (AGO10) is a small RNA effector that regulates meristem development (Zhu et al, Cell,2011) and mutations in AGO10 cause severe developmental abnormalities in the meristem (fig2). We are investigating how different molecular pathways are coordinated during meristem development. Understanding how meristematic cells are programmed will contribute to the progress made in improving crop productivity and preserve food security.
Figure 2. Wild type Arabidopsis seedlings have highly coordinated leaf development. The argonaute10 mutant has severely disrupted meristem development that has been linked to small RNA pathways that regulate tissue polarity.
Computationally Modelling Transcription factor networks
We are collaborating with Dr Scott Grandison at the University of East Anglia to computationally model gene regulatory networks (GRN) in plants. Computational modelling can help us understand how GRN's can arise spontaneously and precisely direct molecular pathways. Currently we have modelled a GRN based on a well characterised transcription factor network in Arabidopsis fruit development (Girin et al. 2009). Many of these transcription factors have functions in the shoot apical meristem development and therefore the computational model will be used to investigate parallels between fruit and shoot apical meristem function.
Figure 3. Visualisation of transcription factor gene expression based on a computational model.
PhD Studentship Available October 2013
Contact k.sorefan@sheffield.ac.uk for further details
PUBLICATIONS
Fuentes S, Ljung K, Sorefan K, Alvey E, Harberd NP, Østergaard L (2012) Fruit Growth in Arabidopsis Occurs via DELLA-Dependent and DELLA-Independent Gibberellin Responses. The Plant Cell Online
Girin T, Paicu T, Stephenson P, Fuentes S, Körner E, O’Brien M, Sorefan K, Wood TA, Balanzá V, Ferrándiz C (2011) INDEHISCENT and SPATULA Interact to Specify Carpel and Valve Margin Tissue and Thus Promote Seed Dispersal in Arabidopsis. The Plant Cell Online
Jiang K, Sorefan K, Deeks MJ, Bevan MW, Hussey PJ, Hetherington AM (2012) The ARP2/3 Complex Mediates Guard Cell Actin Reorganization and Stomatal Movement in Arabidopsis. The Plant Cell Online 24: 2031-2040
Sorefan K, Pais H, Hall AE, Kozomara A, Griffiths-Jones S, Moulton V, Dalmay T (2012) Reducing sequencing bias of small RNAs. Silence 3: 4
Mohorianu I, Schwach F, Jing R, Lopez‐Gomollon S, Moxon S, Szittya G, Sorefan K, Moulton V, Dalmay T (2011) Profiling of short RNAs during fleshy fruit development reveals stage‐specific sRNAome expression patterns. The Plant Journal
Arnaud N, Girin T, Sorefan K, Fuentes S, Wood TA, Lawrenson T, Sablowski R, Østergaard L (2010) Gibberellins control fruit patterning in Arabidopsis thaliana. Genes & development 24: 2127-2132
Sorefan K, Girin T, Liljegren SJ, Ljung K, Robles P, Galván-Ampudia CS, Offringa R, Friml J, Yanofsky MF, Østergaard L (2009) A regulated auxin minimum is required for seed dispersal in Arabidopsis. Nature 459: 583-586
Girin T, Sorefan K, Østergaard L (2009) Meristematic sculpting in fruit development. Journal of experimental botany 60: 1493
Sorefan K, Ostergaard L (2007) Auxin homeostasis and Arabidopsis fruit development. Comparative Biochemistry and Physiology-Part A: Molecular & Integrative Physiology 146: S239-S239
Li Y, Lee KK, Walsh S, Smith C, Hadingham S, Sorefan K, Cawley G, Bevan MW (2006) Establishing glucose-and ABA-regulated transcription networks in Arabidopsis by microarray analysis and promoter classification using a Relevance Vector Machine. Genome Research 16: 414-427
Bainbridge K, Sorefan K, Ward S, Leyser O (2005) Hormonally controlled expression of the Arabidopsis MAX4 shoot branching regulatory gene. The Plant Journal 44: 569-580
Li Y, Sorefan K, Hemmann G, Bevan MW (2004) Arabidopsis NAP and PIR regulate actin-based cell morphogenesis and multiple developmental processes. Plant physiology 136: 3616-3627
Sorefan K, Booker J, Haurogné K, Goussot M, Bainbridge K, Foo E, Chatfield S, Ward S, Beveridge C, Rameau C (2003) MAX4 and RMS1 are orthologous dioxygenase-like genes that regulate shoot branching in Arabidopsis and pea. Genes & development 17: 1469