BIOL 1411 1st Edition Lecture 30Outline of Last Lecture I. MutationsOutline of Current Lecture I. DNA sequencing LectureRelating Genotype with Phenotype- Genetic Markers and the discovery of disease-causing alleleso Genetic markers provide reference loci for associating genotype with phenotype o Knowledge of two mutations is needed: One influences the disease phenotype and the other is a marker mutation Co-inheritance of the marker and the disease-causing allele occurs due to genetic linkage; i.e., the loci are closely linked - Finding the cause of heritable diseaseso Through association with a phenotype caused by genetic linkage, genetic markerssuch as SNPs, STRs, and RFLPs are used as land marks to localize genes of interest- Genetic Screening to Detect Diseaseso Genetic Screening: using tests to determine is an individual has a genetic disease,is predisposed to one, or is a carrier. Tests are at level of genotype or phenotype. Prenatal screening Screening of newborns Screening asymptomatic people with relatives who have genetic diseases - DNA tests to detect diseaseso DNA testing is direct analysis of DNA for mutation; the most accurate way of detecting an abnormal allele.o Pre-implantation screening of a zygote can be used for parents of a child with a disease like cystic fibrosiso Fetal cells and newborns can be tested for sickle-cell disease and others - Genetic causes of heritable disease o Mendelian traits segregate as single autosomal or sex-linked locio Most human traits are multifactorial- caused by interactions of many genes and the environmento Susceptibility to disease is often influenced by these complex genetic interactionsThese 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.o 60 percent of people are affected by diseases that are genetically influenced Human Genome Project- Characteristic of the human genomeo Some interesting facts about the human genome: Protein-coding regions make up less than 2 percent, about 24.000 genes A gene can code several proteins, with posttranscriptional mechanisms An average gene has 27,000 base pairs Human genes have many introns Genes are not evenly distributed over the genome. The y chromosome has the fewest genes (231); chromosome 1 has the most (2,968) Over 50 percent of the genome is transposons and other repetitive sequences, not genes 97 percent of the genome is the same in all people - Studies enabled by sequencing the human genomeo Rapid genotype technologies are being used to understand the genetic basis of diseases such as diabetes, heart disease, and Alzheimer’s diseaseo Genome-wide association studies are designed to identify SNPs linked to genes involved in diseaseo Technologies to analyze SNPs include massively- parallel sequencing methods and DNA microarrays - Analysis of multifactorial traitso Rapid genotype technologies are being used to understand the genetic basis of diseases such are diabetes, heart disease, and Alzheimer’s diseaseo Technologies to analyze SNPs include rapid sequencing and other direct detection methods, eg allele-specific hybridizationo One aim is to associate SNP-defined haplotypes with
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