BCOR 103 1st Edition Lecture 24 Outline of Last Lecture I. GenomicsII. Alternative SplicingIII. Gene FamiliesOutline of Current Lecture I. Human Genome ProjectII. Gene StudiesCurrent Lecture- Human Genome Project: ~10 years/$2.7 billiono DNA source: 6 – 10 anonymous individuals- From slab gels to capillary sequencing and second-generation sequencing technologies, there has been a more than a million-fold improvement in the rate of sequence generation over this time scale. (kb/day/machine)- Hierarchical Clustering is the most popular method for visualizing microarray expression data. In hierarchical clustering, genes with similar expression patterns are grouped together. - Heat map: relative gene expression data visualized by color.- Transcriptional profiling: Objective: use gene expression patterns for diagnosis, prognosis, determination of most effective therapy- Pharmacogenomics: the study of how genetic (genome) differences in MULTIPLE genes influence variability in drug response.- Key concept: gene expression is influenced by more than simply DNA sequence.- Epigenetic modifications are both inheritable (through cell division, and in some cases from parent to offspring) and dynamic (reversible) – influenced by cell development, cellsignaling, environment, etc.- 5-methylcytosine: only know DNA modification: methyl group is displayed in the DNA major groove where it is accessible to regulatory proteins.These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- DNA methylation may occur at symmetric CpG sequences.- DNA methylation within promoter regions: associated with gene silencing- Cell type-specific gene expression patterns may be dictated and maintained by epigenetic modificationso Royal jelly is a complex, protein-rich substance secreted from glands on the heads of worker bees. A larva destined to become a queen is fed large quantities of royal jelly inside a specially constructed compartment called a queen cup. The larvae that develop into workers and queens are genetically identical. But as a result of the royal jelly diet, the queen will develop functional ovaries and a larger abdomen for egg laying, while worker bees remain sterile. She'll also develop the necessary behaviors to act as queen, such as killing rival queens, making communication sounds known as "piping," and going on "mating flights." The queen is fed royal honey exclusively for the rest of her life. In a recent series of experiments, scientists determined that royal jelly silences a key gene (Dnmt3), which codes for an enzyme involved in genome-wide gene silencing. When Dnmt3 is active in bee larvae, the queen genes are epigenetically silenced and the larvae develop into the default "worker" variety. But when royal jelly turns Dnmt3 off, certain genes jump into action that turn the lucky larvae into queens.- Chromosome 3 pairs in each set of twins are digitally superimposed. One twin's epigenetic tags are dyed red and the other twin's tags are dyed green. When red and green overlap, that region shows up as yellow. The 50-year old twins have more epigenetic tags in different places than do 3-year-old twins.- Key concept: Environmental factors influence epigenetic modifications which in turn influence gene expression.- Calico cats are always female (almost true, some XXY males have been calico) one X chromosome carries the gene for black coat color and the other X chromosome carries the gene for yellow coat color in 64-cell embryos, one of each pair of X chromosomes and its genes are randomly silenced daughter cells inherit active or inactive X chromosomes, creating a cat with patches of coat color.- Reproductive cloning: production of an entire organism, example: Dolly.- Therapeutic cloning: production of cells or tissues for therapeutic