Approach to Genome Analysis

The approach to genome analysis encompasses
several goals. Of primary interest is the number,
type, and distribution of genes. Knowing all
genes and their positions and structures in a
eukaryotic genome will provide the basis for
understanding their function. The size of a
genome needs to be taken into account for a
systematic study.
Two basic approaches to sequencing a genome
can be distinguished: clone-by-clone sequencing
and the so-called shotgun approach. In the
former, individual DNA clones of known relation
to each other are isolated, arranged in their
proper alignment, and sequenced. The shotgun
approach breaks the genome into millions of
fragments of unknown relation. The individual
DNA clones, for which prior knowledge of their
precise origin is lacking, are sequenced. Subsequently,
they are aligned by high-capacity
computers. The two approaches complement
each other.