1 Chapter 2 Genome Organization and Gene Expression

2 Chromosome, nucleosome, chromatin Heterochromatin, euchromatin Centromeres, telomere Tandem repeats, dispersed repeats (simple sequence repeats, microsatellites), transposons (jumping genes)

3 Figure 2.1 Chromosomal landmarks, including centromeres, telomeres, and nucleolar organizers centromere telomere Nucleolar organizer Heterochromatic regions

4 Figure 2.2 The two major classes of transposons differ in their mode of transposition

5 Figure 2.3 Loss of methylation can lead to mutations Methylation of transposons play important roles in genome stabling

6 Figure 2.4 Meiosis in plants Polyploids contain multiple copies of the entire genome Autopolyploids: from a single species Allopolyploids: from two or more species

7 Figure 2.5 Polyploidy arises by genome duplication

8 Figure 2.6 Three common species of plants in the mustard family (Brassicaceae)

9 Figure 2.7 (A) Maize plants of same age; (B) Relationship between plant vigor and ploidy level

10 Figure 2.10 Vegetative segregation can lead to variegation Organellar genetics donot obey Mendelian laws

11 Regulation of gene expression Transcriptional regulation Post-transcriptional regulation –mRNA stability –Translation efficiency –Degradation –Protein stability (posttranslational regulation)

12 Figure 2.11 Gene expression in eukaryotes

13 Figure 2.13 Methylation of cytosine, lysine, histones; acetylation of histones catalyzed by histone acetyltransferases (HATs)

(1) RNAi pathways in plants; (A) MicroRNA pathway RISC: RNA- induced silencing complex

(2) RNAi pathways in plants; (B) Short interfering RNA pathway RdRP: RNA- dependent RNA polymerase

16 Figure 2.15 Diagram of the cytoplasmic pathway of protein degradation

17 Figure 2.16 Two-color labeling is a microarray technique used to compare gene expression

18 Figure 2.16 Two-color labeling is a microarray technique used to compare gene expression

19 Figure 2.17 Agrobacterium’s tumor-inducing (Ti) plasmid

20 Figure 2.19 Classic breeding and domestication of wild grass teosinte led to the crop plant maize

21 Figure 2.20 Golden rice was produced by inserting foreign genes into rice

22 Tools to study gene function Gene transcription: Northern blotting, reverse transcription (RT-) PCR, in situ hybridization Microarray Report gene fusion Transformation