1. Chapter 13  Differential Gene Expression & plant development

2. Regulation of gene expression  Environmental stimuli  Hormones  Transcription factors  microRNAs

3. Arabidopsis

4. MicroRNAs  Overexpression of miR156

11. microRNAs and RNAi  RNAi – RNA interference –Used to determine the consequences of down-regulating gene expression

12. Technologies used in gene identification  RNAi  Mutational studies  Transposon tagging  Microarray analysis

13. Arabidopsis

14. Transposable elements

15.  AC and DS in maize –AC encodes transposase, required to excise DS

16. Transposon tagging

17. Transposon tagging utilizes colorimetric expression assays  GUS reporter gene (B-glucuronidase), E. coli  GFP (green fluorescent protein), jellyfish

18. DNA microarrays  Can accommodate ~20,000 genes

20. Microarrays and development  Example –Vegetative meristem mRNA labeled green –Flower bud mRNA labeled red

21. The discovery of microRNAs has resulted in which gene analysis technology? 1. RNAi 2. Chemical mutagenesis 3. Transposon tagging 4. Microarray analysis

22. GUS and GFP reporter genes are utilized in 1. RNAi 2. Chemical mutagenesis 3. Transposon tagging 4. Microarray analysis

23. Comparing gene expression under two different conditions is best accomplished using 1. RNAi 2. Chemical mutagenesis 3. Transposon tagging 4. Microarray analysis

24. Determining which tissues a gene is expressed in can be examined using 1. RNAi 2. Chemical mutagenesis 3. Transposon tagging 4. Microarray analysis 5. More than one of the above