Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Human Genetics Concepts and Applications Seventh Edition Powerpoint Lecture Outline Ricki Lewis Prepared by Mary King Kananen Penn State Altoona

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Chapter 11 Control of Gene Expression

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Gene Expression Over Time Changes in gene expression may occur over time This may occur at the molecular, tissue, or organ gland level May be a response to environment

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Globin Chain Switching Adult hemoglobin has four polypeptide chains Genes for alpha and beta subunits are located on chromosome 11 and 16 respectively Subunits change in response to oxygen levels Subunit makeup varies between embryo, fetus, and adult

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Hemoglobin Composed of: Globular proteins Two alpha chains and two beta chains They surround an iron-containing heme group Figure 11.1

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Globin Chain Switching Figure 11.2

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Changing Gene Expression in Blood Plasma Blood plasma contains 40,000 different types of protein Changing conditions cause a change in the protein profile of the plasma Stem cell biology is beginning to shed light on how genes are turned on and off

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Pancreas Exocrine and endocrine function Differential gene expression produces either endocrine or exocrine cells If transcription factor pdx-1 is activated, some progenitor cells follow the exocrine pathway Figure 11.3

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Table 11.1

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Differential Gene Expression Figure 11.4

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Proteomics Uses analytical chemistry and microarrays to study all proteins produced Fourteen categories of proteins Variation in gene expression over lifespan and environment

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Figure 11.5

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Mechanisms of Gene Expression Transcription factors Histone code –Histones play a major role in exposing DNA for transcription –Important molecules: acetyl groups, methyl groups, and phosphates

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Control of DNA Expression Figure 11.6

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display RNA Interference Promotes gene silencing in the nucleus Removes certain mRNAs in the cytoplasm

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Figure 11.8

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Proteins Outnumber Genes 1.5% of human genome encodes protein 25,000 genes specify up to 200,000 proteins Use of exon shuffling, alternative splicing, interons, and cutting proteins translated from a single gene

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Alternative Splicing within a Gene Figure 11.9

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Dentinogenesis imperfecta Caused by deficiency in proteins DPP and DSP Both are cut from same larger protein Figure 11.10a

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display DPP and DSP Figure 11.10b

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Majority of Human Genome Does not Encode Protein Rest of genome encodes for Noncoding RNAs Introns Promoters Other controls Repeats

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Table 11.4