Chapter 13  Differential Gene Expression & plant development

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

Arabidopsis

MicroRNAs  Overexpression of miR156

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

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

Arabidopsis

Transposable elements

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

Transposon tagging

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

DNA microarrays  Can accommodate ~20,000 genes

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

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

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

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

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