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Genome biology and evolution

genome biology and genome research and comparative genomics biology definition
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Dr.SamuelHunt,United Arab Emirates,Teacher
Published Date:21-07-2017
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Introduction to Genome Biology Sandrine Dudoit and Robert Gentleman Bioconductor Short Course 2003 © Copyright 2002, all rights reservedOutline • Cells, chromosomes, and cell division • DNA structure and replication • Proteins • Central dogma: transcription, translation • Microarrays • PathwaysA brief history Gregor Mendel (1823-1884) Thomas Hunt Morgan (1866-1945) Francis Crick (1916- ) James D. Watson (1928- )From chromosomes to proteinsCellsCells • Cells: the fundamental working units of every living organism. • Metazoa: multicellular organisms. E.g. humans: trillions of cells. • Protozoa: unicellular organisms. E.g. yeast, bacteria.Cells • Each cell contains a complete copy of an organism’s genome, or blueprint for all cellular structures and activities. • Cells are of many different types (e.g. blood, skin, nerve cells), but all can be traced back to a single cell, the fertilized egg.Cell composition • 90% water. • Of the remaining molecules, dry weight – 50% protein – 15% carbohydrate – 15% nucleic acid – 10% lipid – 10% miscellaneous. • By element: 60% H, 25% O, 12%C, 5%N.The genome • The genome is distributed along chromosomes, which are made of compressed and entwined DNA. • A (protein-coding) gene is a segment of chromosomal DNA that directs the synthesis of a protein.The human genome • The human genome is distributed along 23 pairs of chromosomes –22 autosomal pairs; –the sex chromosome pair, XX for females and XY for males. • In each pair, one chromosome is paternally inherited, the other maternally inherited (cf. meiosis).ChromosomesChromosome banding patternsOf mice and menChromosomes and DNADNA structure “We wish to suggest a structure for the salt of deoxyribose nucleic acid (D.N.A.). This structure has novel features which are of considerable biological interest.” J.D. Watson & F. H. C. Crick. (1953). Molecular structure of Nucleic Acids. Nature. 171: 737-738.DNA structure •A deoxyribonucleic acid or DNA molecule is a double-stranded polymer composed of four basic molecular units called nucleotides. • Each nucleotide comprises – a phosphate group; – a deoxyribose sugar; – one of four nitrogen bases: • purines: adenine (A) and guanine (G), • pyrimidines: cytosine (C) and thymine (T).DNA structureDNA structureNucleotide bases Purines Adenine (A) Guanine (G) Pyrimidines Thymine (T) Uracil (U) Cytosine (C) (DNA) (RNA)DNA structure • Polynucleotide chains are directional molecules, with slightly different structures marking the two ends of the chains, the so- called 3' end and 5' end. • The 3' and 5' notation refers to the numbering of carbon atoms in the sugar ring. • The 3' end carries a sugar group and the 5' end carries a phosphate group. • The two complementary strands of DNA are antiparallel (i.e, 5' end to 3' end directions for each strand are opposite)