* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Unit2Day5
Polycomb Group Proteins and Cancer wikipedia , lookup
X-inactivation wikipedia , lookup
Oncogenomics wikipedia , lookup
Human genome wikipedia , lookup
Biology and consumer behaviour wikipedia , lookup
Pathogenomics wikipedia , lookup
Transposable element wikipedia , lookup
Human genetic variation wikipedia , lookup
Ridge (biology) wikipedia , lookup
Epigenetics in learning and memory wikipedia , lookup
Neuronal ceroid lipofuscinosis wikipedia , lookup
Point mutation wikipedia , lookup
Saethre–Chotzen syndrome wikipedia , lookup
Genetic engineering wikipedia , lookup
Copy-number variation wikipedia , lookup
Vectors in gene therapy wikipedia , lookup
Long non-coding RNA wikipedia , lookup
Epigenetics of neurodegenerative diseases wikipedia , lookup
Public health genomics wikipedia , lookup
Genomic imprinting wikipedia , lookup
History of genetic engineering wikipedia , lookup
Epigenetics of human development wikipedia , lookup
Gene therapy wikipedia , lookup
Mir-92 microRNA precursor family wikipedia , lookup
Gene desert wikipedia , lookup
Gene therapy of the human retina wikipedia , lookup
Helitron (biology) wikipedia , lookup
Epigenetics of diabetes Type 2 wikipedia , lookup
Genome (book) wikipedia , lookup
Gene nomenclature wikipedia , lookup
Nutriepigenomics wikipedia , lookup
Genome evolution wikipedia , lookup
Therapeutic gene modulation wikipedia , lookup
Site-specific recombinase technology wikipedia , lookup
Gene expression profiling wikipedia , lookup
Gene expression programming wikipedia , lookup
Microevolution wikipedia , lookup
Mutation examples involving switches • What Darwin never knew (switches) video • http://www.pbs.org/wgbh/nova/evolution/d arwin-never-knew.html • Watch 1:44:00 to 1:49:15 • The work highlighted in the Nova piece on Katie Pollard fits nicely with earlier studies comparing gene expression patterns in human and chimp. 2002: Gene expression differences weren’t that different in non-brain tissues… Gene activity, not sequence, “makes us human” Enard et al., Science, 2002, 296: 340-343 2003: Gene expression in human and chimp cerebral cortex … Red = increased expression 169 different genes with expression differences between human and chimp in cortex Most genes were more highly expressed in human vs. chimp Caceres et al., 2003, PNAS, 100: 13030-13035 Katie Pollard’s work implicates the “switches” as the genetic mechanism behind the gene expression differences Prx1 Prx1 is naturally expressed at different levels in bat and mouse during limb development Created knock-in mice (replaced mouse switch with bat switch for Prx1). Limb length was increased 6% (sig) Cretekos et al., 2008, Genes and Development • Sean Carroll, “switches” and fly wing spots (gene expression is turned on by particular sequence) A glimpse of the actual wing trans-regulatory landscape. Prud'homme B et al. PNAS 2007;104:8605-8612 ©2007 by National Academy of Sciences Prud'homme B et al. PNAS 2007;104:8605-8612 ©2007 by National Academy of Sciences Body-plan evolution by compounding regulatory changes. Prud'homme B et al. PNAS 2007;104:8605-8612 ©2007 by National Academy of Sciences Schematic comparison of Hoxc8 expression in chicken and mouse in relationship to morphological landmarks. Belting H et al. PNAS 1998;95:2355-2360 ©1998 by The National Academy of Sciences Hoxc8 figure from Time Mag. Examples involving gene duplication • Can arise by unequal crossing over (gene duplication) • Can arise by genome duplication (failure of meiosis to produce haploid gamete) Is it common? • Several hundred duplicated genes every million years in Drosophila Gene Duplications • Especially important in evolution… – Can change protein quantity (e.g., human amylase) – Duplicated gene may take on a new job if mutation alters it – Duplicated gene may be expressed at a different time or location if “switch” sequence is altered Gene Duplication seems to be more common in our lineage than in other primate lineages Marques-Bonet et al., Nature, Feb. 12, 2009 Gene duplication seems especially common in the human lineage even compared to the chimp/bonobo lineage… does this account for gene expression diffferences we discussed earlier? Marques-Bonet et al., Nature, Feb. 12, 2009 Color vision is useful… http://www.neitzvision.com/content/home.html Color vision in Old World Primates (including humans) is trichromatic Jacobs and Nathans, Scientific American, April 2009 Red and green genes are very similar and are likely due to a duplication event (unequal crossover) and gene cooption Jacobs and Nathans, Scientific American, April 2009 Both males and females are trichromatic… Jacobs and Nathans, Scientific American, April 2009