2 Nucleic Acids and Nuclear Proteins
2.1
2.1.1
2.1.2
2.1.3
2.1.4
2.2
2.3
2.3.1
2.3.2
2.3.3
2.3.4
2.3.S
2.3.6
2.4
2.4.1
2.4.2
2.S
2.S.1
2.S.2
2.S.3
2.S.4
The Structure of Chromosomal DNA
Conformation and Composition
Base Sequence and Gene Structure
The Genetic Code
Introns
Multiple Genes and Pseudogenes
Repetitive Sequences and Mobile Elements
Satellite DNA
Middle Repetitive DNA
and Genome Organization
Transposition of Middle Repetitive Sequences
Mobile Sequences of Invertebrates
The Retroposons of Vertebrates
Retropseudogenes
Size of the Genome
The DNA Content of Haploid Genomes
(the C Value)
Increase and Decrease in the DNA Content
of Individual Cells
Chromatin Proteins
Structure and Evolution of the Histones
The Histone Genes
Variability of the Histones
Protamines
2.1 The Structure of Chromosomal DNA
DNA deserves the most attention in any book
dealing with molecular variety in animals. The
complete genetic information of the organism is
encoded in the order of the bases, and with it also
is the whole spectrum of genetically determined
variation within and between individuals. One
can view DNA as a text in which each of the four
letters at each position has a unique meaning.
Some information and variety is lost en route
from the DNA via RNA to the proteins and the
complex morphological and physiological characters because only part of the DNA is transcribed
into RNA, and not all RNA codes for proteins;
furthermore, the genetic code is degenerate and
the 64 possible triplet co dons define only 20
amino acids. Sequence differences between proteins may also have no consequences for complex
phenotypic characters. On the other hand, new
2.S.S
2.6
2.7
2.7.1
2.7.2
2.7.3
2.7.4
2.7.S
2.7.6
2.8
2.8.1
2.8.2
2.8.3
2.8.4
2.8.S
2.8.6
2.9
2.9.1
2.9.2
2.9.3
2.9.4
Non-Histone Proteins
DNA Replication and Repair
Transcription and RNA Maturation.
RNA Polyrnerases
Transcription
Maturation of the Primary Transcripts
(RNA Processing)
Production of Multiple Transcripts of a Gene
Regulation of Transcription
Heat-Shock Genes and Heat-Shock Proteins
Ribonucleic Acids and Ribonucleoproteins
The rRNA Genes and Their Transcription
Structure of rRNAs
The SS rRNAs and Their Genes
Ribosomal Proteins
The Transfer RNAs and Their Genes
The Small Nuclear RNAs and Their Genes
Mitochondrial DNA
The mtDNA of Vertebrates
The mtDNA of Invertebrates
The mtDNA of Ciliates
Kinetoplast DNA
References
(epigenetic) variability can arise during the information transfer process as a result of environmental factors.
The genetic information in the DNA that is
passed from generation to generation is not as
rigidly and inalterably inscribed as the text in a
book. Spontaneous reactions, external factors
and mistakes during replication, so long as they
are not corrected by the cell's repair system, produce persistent changes in the genetic information.
When this occurs in somatic cells, malfunction or
neoplastic growth may result, and the survival
chances of the individual are reduced. Mutations
in germ cells, however, may spread through the
progeny and instigate the evolutionary process.
The latest results of molecular biology research
have shown genetic alteration to be far more frequent than was previously assumed. The animal
genome appears today as a dynamic system
whose structure changes from one cell generation
2.1
2.1.1
2.1.2
2.1.3
2.1.4
2.2
2.3
2.3.1
2.3.2
2.3.3
2.3.4
2.3.S
2.3.6
2.4
2.4.1
2.4.2
2.S
2.S.1
2.S.2
2.S.3
2.S.4
The Structure of Chromosomal DNA
Conformation and Composition
Base Sequence and Gene Structure
The Genetic Code
Introns
Multiple Genes and Pseudogenes
Repetitive Sequences and Mobile Elements
Satellite DNA
Middle Repetitive DNA
and Genome Organization
Transposition of Middle Repetitive Sequences
Mobile Sequences of Invertebrates
The Retroposons of Vertebrates
Retropseudogenes
Size of the Genome
The DNA Content of Haploid Genomes
(the C Value)
Increase and Decrease in the DNA Content
of Individual Cells
Chromatin Proteins
Structure and Evolution of the Histones
The Histone Genes
Variability of the Histones
Protamines
2.1 The Structure of Chromosomal DNA
DNA deserves the most attention in any book
dealing with molecular variety in animals. The
complete genetic information of the organism is
encoded in the order of the bases, and with it also
is the whole spectrum of genetically determined
variation within and between individuals. One
can view DNA as a text in which each of the four
letters at each position has a unique meaning.
Some information and variety is lost en route
from the DNA via RNA to the proteins and the
complex morphological and physiological characters because only part of the DNA is transcribed
into RNA, and not all RNA codes for proteins;
furthermore, the genetic code is degenerate and
the 64 possible triplet co dons define only 20
amino acids. Sequence differences between proteins may also have no consequences for complex
phenotypic characters. On the other hand, new
2.S.S
2.6
2.7
2.7.1
2.7.2
2.7.3
2.7.4
2.7.S
2.7.6
2.8
2.8.1
2.8.2
2.8.3
2.8.4
2.8.S
2.8.6
2.9
2.9.1
2.9.2
2.9.3
2.9.4
Non-Histone Proteins
DNA Replication and Repair
Transcription and RNA Maturation.
RNA Polyrnerases
Transcription
Maturation of the Primary Transcripts
(RNA Processing)
Production of Multiple Transcripts of a Gene
Regulation of Transcription
Heat-Shock Genes and Heat-Shock Proteins
Ribonucleic Acids and Ribonucleoproteins
The rRNA Genes and Their Transcription
Structure of rRNAs
The SS rRNAs and Their Genes
Ribosomal Proteins
The Transfer RNAs and Their Genes
The Small Nuclear RNAs and Their Genes
Mitochondrial DNA
The mtDNA of Vertebrates
The mtDNA of Invertebrates
The mtDNA of Ciliates
Kinetoplast DNA
References
(epigenetic) variability can arise during the information transfer process as a result of environmental factors.
The genetic information in the DNA that is
passed from generation to generation is not as
rigidly and inalterably inscribed as the text in a
book. Spontaneous reactions, external factors
and mistakes during replication, so long as they
are not corrected by the cell's repair system, produce persistent changes in the genetic information.
When this occurs in somatic cells, malfunction or
neoplastic growth may result, and the survival
chances of the individual are reduced. Mutations
in germ cells, however, may spread through the
progeny and instigate the evolutionary process.
The latest results of molecular biology research
have shown genetic alteration to be far more frequent than was previously assumed. The animal
genome appears today as a dynamic system
whose structure changes from one cell generation