BIOL-L211 Lecture 25 Outline of Last Lecture I. Article (cont.)II. Activators, Repressors, and Synergism III. EpigeneticsOutline of Current Lecture I. EpigeneticsII. ArticleIII. Epigenetic TherapyIV. RNA SplicingCurrent LectureEpigenetics (cont.) and RNA SplicingI. EpigeneticsA. Epigenetics and Nutrition1. Certain foods are advised during pregnancya. Folate promotes proper formation of the neural tube by donating methyl groups for DNA methylation2. Babies inherit methylation patterns from mothersB. Agout gene in mice1. Agouti mice (yellow & obese), were used in breeding experiments2. Diets varied in nutrients that supply methyl groupsThese 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.3. Agout gene was affected in offspringa. Methylated: gene off -> healthier mouseb. Unmethylated: gene on -> yellow and obese; prone to diabetes and cancer mouse4. Epigenetic changes found to have a correlation with low birth rate and diseaseC. Cancer1. "Cancer is a term used for diseases in which abnormal cells divide without control and are able to invade other tissues." –National Cancer Institute Website2. A result of mutations affecting cell growth and division3. Cells do not die when they should4. Tumors may form5. Six Biological Abilities of Cancer Cells:-Self-stimulated growth-Evades signals to stop growing-Activates invasion of local tissues and metastasizes-Multiplication without termination-Resistance to apoptosis-Induces blood vessel growth to increase nutrient supply to tumorsII. ArticleA. "The Long Trail of Cancer's Clues" –Scientfic American, November 2013B. Chemical modifications can be altered without mutating DNA1. May be rearranged2. May be added or removed (ex: methylation)III. Epigenetic TherapyA. DNA and histone modifications are reversibleB. Commercial supplements are available1. Lunasin: Peptide from soy2. Reliv (company) sells Lunasin as a promoter of optimal health at the epigenetic levelC. Medicine1. Some prescription drugs work by blocking DNA methylation or inhibiting HDACactivityD. Becomes an issue if modifications are widespreadE. Important to target abnormal cells and not healthy cellsIV. RNA SplicingA. Form of RNA processing which removes introns and connects exonsB. Spliceosome: recognizes intron-exon boundaries1. Complex of proteins and non-coding RNA2. Recognizes 5' and 3' ends of each intron3. Recognizes a sequence within the intron C. Spliceosome recognizes the following sequences of each intron:1. 5' splice site: boundary between exon and intron2. Branch site: sequence internal to intron3. 3' splice site: boundary between intron and exon4. Sequences are conserved within all introns of a species5. Variation exists between speciesD. Important symbols to note:1. "N" can represent any base2. "Y" means that any pyrimidine can be added and still be recognized by spliceosome3. "R" means any purine can be added and still be recognized by
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