@article{YanChenKaufmann2016, author = {Yan, Wenhao and Chen, Dijun and Kaufmann, Kerstin}, title = {Efficient multiplex mutagenesis by RNA-guided Cas9 and its use in the characterization of regulatory elements in the AGAMOUS gene}, series = {Plant methods}, volume = {12}, journal = {Plant methods}, publisher = {BioMed Central}, address = {London}, issn = {1746-4811}, doi = {10.1186/s13007-016-0125-7}, pages = {1 -- 9}, year = {2016}, abstract = {Background The efficiency of multiplex editing in plants by the RNA-guided Cas9 system is limited by efficient introduction of its components into the genome and by their activity. The possibility of introducing large fragment deletions by RNA-guided Cas9 tool provides the potential to study the function of any DNA region of interest in its 'endogenous' environment. Results Here, an RNA-guided Cas9 system was optimized to enable efficient multiplex editing in Arabidopsis thaliana. We demonstrate the flexibility of our system for knockout of multiple genes, and to generate heritable large-fragment deletions in the genome. As a proof of concept, the function of part of the second intron of the flower development gene AGAMOUS in Arabidopsis was studied by generating a Cas9-free mutant plant line in which part of this intron was removed from the genome. Further analysis revealed that deletion of this intron fragment results 40 \% decrease of AGAMOUS gene expression without changing the splicing of the gene which indicates that this regulatory region functions as an activator of AGAMOUS gene expression. Conclusions Our modified RNA-guided Cas9 system offers a versatile tool for the functional dissection of coding and non-coding DNA sequences in plants.}, language = {en} } @article{YanChenKaufmann2016, author = {Yan, Wenhao and Chen, Dijun and Kaufmann, Kerstin}, title = {Efficient multiplex mutagenesis by RNA-guided Cas9 and its use in the characterization of regulatory elements in the AGAMOUS gene}, series = {Plant Methods}, volume = {12}, journal = {Plant Methods}, publisher = {BioMed Central}, address = {London}, issn = {1746-4811}, doi = {10.1186/s13007-016-0125-7}, pages = {2381 -- 2389}, year = {2016}, abstract = {Results: Here, an RNA-guided Cas9 system was optimized to enable efficient multiplex editing in Arabidopsis thaliana. We demonstrate the flexibility of our system for knockout of multiple genes, and to generate heritable large-fragment deletions in the genome. As a proof of concept, the function of part of the second intron of the flower development gene AGAMOUS in Arabidopsis was studied by generating a Cas9-free mutant plant line in which part of this intron was removed from the genome. Further analysis revealed that deletion of this intron fragment results 40 \% decrease of AGAMOUS gene expression without changing the splicing of the gene which indicates that this regulatory region functions as an activator of AGAMOUS gene expression. Conclusions: Our modified RNA-guided Cas9 system offers a versatile tool for the functional dissection of coding and non-coding DNA sequences in plants.}, language = {en} } @article{MuinodeBruijnPajoroetal.2016, author = {Muino, Jose M. and de Bruijn, Suzanne and Pajoro, Alice and Geuten, Koen and Vingron, Martin and Angenent, Gerco C. and Kaufmann, Kerstin}, title = {Evolution of DNA-Binding Sites of a Floral Master Regulatory Transcription Factor}, series = {Molecular biology and evolution}, volume = {33}, journal = {Molecular biology and evolution}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0737-4038}, doi = {10.1093/molbev/msv210}, pages = {185 -- 200}, year = {2016}, abstract = {Flower development is controlled by the action of key regulatory transcription factors of the MADS-domain family. The function of these factors appears to be highly conserved among species based on mutant phenotypes. However, the conservation of their downstream processes is much less well understood, mostly because the evolutionary turnover and variation of their DNA-binding sites (BSs) among plant species have not yet been experimentally determined. Here, we performed comparative ChIP (chromatin immunoprecipitation)-seq experiments of the MADS-domain transcription factor SEPALLATA3 (SEP3) in two closely related Arabidopsis species: Arabidopsis thaliana and A. lyrata which have very similar floral organ morphology. We found that BS conservation is associated with DNA sequence conservation, the presence of the CArG-box BS motif and on the relative position of the BS to its potential target gene. Differences in genome size and structure can explain that SEP3 BSs in A. lyrata can be located more distantly to their potential target genes than their counterparts in A. thaliana. In A. lyrata, we identified transposition as a mechanism to generate novel SEP3 binding locations in the genome. Comparative gene expression analysis shows that the loss/gain of BSs is associated with a change in gene expression. In summary, this study investigates the evolutionary dynamics of DNA BSs of a floral key-regulatory transcription factor and explores factors affecting this phenomenon.}, language = {en} }