DNA Sequence and Chromosome Organization

Content of Nucleic Acid Synthesis
» Nucleic Acids
» Structure and Function of Nucleic Acids
    » Basic Chemical Structure
    » Base Pairing in Nucleic Acids: Double Helical Structure of Dna
    » Size, Structure, Organization, and Complexity of Genomes
    » Information Storage, Processing, and Transfer
    » Chromosomal Dna Compaction and Its Implications in Replication and Transcription
    » DNA Sequence and Chromosome Organization
    » Repetitive Sequences: Selfish DNA
    » Chromatin Remodeling and Histone Acetylation
» Nucleic Acid Syntheses
    » Similarity of DNA and RNA Synthesis
    » DNA Replication Vs Transcription: Enzymatic Processes
    » Multiplicity of DNA and RNA Polymerases
» DNA Replication and Its Regulation
    » DNA Replication
    » Regulation of DNA Replication
    » Regulation of Bacterial DNA Replication at the Level of Initiation
    » DNA Chain Elongation and Termination in Prokaryotes
    » General Features of Eukaryotic DNA Replication
    » Licensing of Eukaryotic Genome Replication
    » Fidelity of DNA Replication
    » Replication of Telomeres—The End Game
    » Telomere Shortening: Linkage Between Telomere Length and Limited Life Span
» Maintenance of Genome Integrity
» DNA Manipulations and their Applications
» Transcriptional Processes
    » Recognition of Prokaryotic Promoters and Role of S-Factors
    » Regulation of Transcription in Bacteria
    » Eukaryotic Transcription
    » RNA Splicing in Metazoans
    » Regulation of Transcription in Eukaryotes
    » Fidelity of Transcription (RNA Editing)
» Chemical Synthesis of Nucleic Acids (Oligonucleotides)
» Bibliography of Nucleic Acid Synthesis
The massive human genome project should achieve its goal of determining the complete sequence of human and mouse genomes in the near future; a “rough draft” has already been obtained. Furthermore, this genome initiative, pursued by both government and private enterprises in the United States and other countries, has already culminated in elucidating the complete sequence of E. coli and other bacteria, as well as yeast, a nematode, and the fruitfly Drosophila melanogaste. Significant progress has been made in elucidating the nucleotide sequences of both human and mouse genomes by using a two-pronged approach. On one hand, the sequences of transcribed regions of the genomes are being deduced from sequences of randomly isolated mRNA segments reverse transcribed into DNAs. At the same time, complete DNA sequences of fragments of whole chromosomes are being directly determined. This has opened up a huge scientific challenge of deciphering the genetic information, identifying unknown genes and their encoded proteins, and the variability of gene sequences with corresponding changes in the protein sequences in individuals. Functional genomics is a newly created discipline which deals with the deterministic prediction of protein functions from the primary sequences. One extension of such analysis is to ascertain the consequences of allelic polymorphisms in the human genome, i.e., minor changes in the sequences of cellular proteins which do not cause an explicit pathological phenotype and yet may affect survival and predisposition to specific diseases in the long term.