Chapter !1 - Introduction to Genomics Code : KSI0010

<Index of Chapter 1>

The human genome

Phenotype = Genotype +Environment + Life history + Epigenetics

Genotype is DNA sequence both nuclear and mitochondrial. 

Phenotype is the collection of your observable traits other than your DNA sequences. 

Life story includes the integrated total of your experiences and the physical and psychological environment in which you developed. 

At the interface between the genome and life experience are epigenetic factors. 

A genome is like a page of printed music. The page is a fixed physical object, but the notes are consistent with realizations, in time and space, in a variety of ways.

- a limited variety of ways. 

 

Contents of the human genome

Francis Crick encapsulated this scheme in the Central Dogma of Molecular biology. 

DNA makes RNA makes Protein.

The most prominent and familiar asepects of the genome, the regions that code for proteins. Protein coding genes are transcribed into messenger RNA(mRNA).

After processing, ribosomes translate mature mRNA to polypeptide chains. 

Some regions of the genome encode non-protein coding RNA molecules( that's RNAs exclusive of messenger RNAs), including but not limited to transfer RNAs, the RNA components of ribosomes and microRNAs and small interfering RNAs that regulate translation.

Other regions contain binding sites for ligands responsible for regulation of transcription. In assessing the total amount of the genome dedicated to control, one would need to include both the regulatory sites themselves, and all the proteins and RNAs encoded that have regulatory functions, arguably including receptors. 

 

 

Genes that encode the proteome

Proteome- that is the amino acid sequences of the proteins expressed. However, several mechanisms introduce additional variety into the genome - protemeome relationship.

In eukaryotes, a mechanism of generating variety from a single gene sequence is alternative splicing. Alternative splicing involves forming a mature from a gene, but always in the order in which they appear in the genome. 

In both prokaryotes and eukaryotes, RNA editing can produce one or more proteins for which the amino-acid sequence may differ from that predicted from the genome seuqnce. 

The leap from the one-dimensional world of sequences to the three dimensional world we inhabit.

DNA sequence determines protein sequence.

Protein sequence determines protein structure

Protein structure determines protein function.

 

Varieties of genome organization

Chromosomes. organlleles, and plasmids. 

 

 

Genome sequencing projects

Variations within and between populations

Human genome sequencing

The human genome and medicine

The evolution and development of databases

Protein evolution : Divergence of sequences and structures within and between species

Ethical, lega and social issues